 All right. Good afternoon, everybody. I'm Elizabeth Rosen with Rosen preservation in Kansas City and it is my pleasure to be here this afternoon to moderate today's webinar about replacement windows for historic buildings and how to manage compromise. I want to let's see we're going to start with a few housekeeping notes. So first of all this event is the session is being recorded and it will be available in the forum webinar library, following the event. Follow up information, including how to access the recording will be sent to the email address that you use to register. Close captioning is enabled and available through your control bar at the bottom of the screen. Please use the q amp a function to submit questions directly to the speakers at any point during the presentation, and you can use the chat function to share your thoughts with the entire group. Lastly, please abide by the conference code of conduct, and I think Rhonda has posted a link to that code of conduct in the chat. So with that, we will get started and and I think while I'm doing introduction for our speaker this morning, Rhonda is going to post a poll to help us understand how you are engaged with this topic in what capacity. While you're doing that it is my very great pleasure to introduce this afternoon speaker, john sander. John has worked as an architectural historian in the technical preservation services division of the National Park Service since 1996. He reviews rehabilitation projects in seeking certification for federal historic tax credits and provides assistance to the users of the program and the general public on technical aspects of preservation. He previously worked as an architectural coordinator for the West Virginia State Historic Preservation Office, and has experience as a preservation consultant and a carpenter. He is a graduate of Carnegie Mellon University in architecture. Locally he's active in the latrobe chapter of the Society of Architectural Historians, and the DC preservation League, both of which he has served as president. So thank you john and I will let you take it away. Thanks very much Elizabeth. And thank you all for joining me today. Let me see if I can move. I'm not sure why my screen is not advancing here. I think you're at the end of the presentation and you might have to. I'm on the first slide so I'm not sure how that would be the case. I'll wait to see if Rhonda can help me figure this one out, because I'm not sure. In the bottom left corner. Yes. Yeah, there should. Do you see the tiny little yeah, the little. Okay so that's what I need you to advance. Sorry we didn't get that coverage first thanks everybody. All right, if you've joined us here for the program today I assume that you do not need to be convinced of the importance of windows to the character of historic buildings, and the importance of the historic window to the integrity of that building. That's something we're not going to bother to even address, looking from who you all are clearly a lot of you are preservation professionals I hope we're not talking too far down the spectrum for you to get something useful out of this. So TPS use the secretary of the interior standards for rehabilitation to judge the work that that comprises historic rehabilitations that are as Elizabeth mentioned seeking certification for federal tax credits. Many of you may use them as well to guide a variety of programs you work with some tax credits local review all sorts of things. So TPS prioritizes repair over replacement, and it requires match when replacement is needed. It's possible to repair just about anything, but there is a point where repair is just not reasonable. You may end up with more new wood that old or more epoxy than would. So I think, even within the standards as an understanding that replacement sometimes is called for. So it depends on the agenda of who's drawing it. And that is a worthy subject for a whole separate presentation and discussion, and not one that we're going to have here today. We're going to be looking at the replacement windows themselves, once you've gotten across that threshold and decided you need them. And really, at least in the projects I look at. We don't even have historic windows in the buildings that we're looking at their long gone. They've either been just out or they've been replaced by some modern aluminum or vinyl, or some other inappropriate window, or what somebody thought at the time wasn't appropriate window. Even when they're not there, there, even though when we do have historic windows, there can be forces in place that are moving the decision toward replacement when repair might have even been feasible. The presence of hazardous materials, operability needs, including egress, thermal and sound transmission needs, all can come into play in a decision to decide to replace a window. Even though most of these can be addressed without losing the historic window, depending on the window and the needs, it may not always be possible to do so reasonably. While it may be possible to put a very good quality storm window out of wood on window, it may be very difficult to come up with a strategy for improving the thermal efficiency of a factory steel sash with a pivot window in the very middle. Like how do you get a storm that gets out of the way so you can open the window. There are any number of factors that can make it complicated, even when your goal is really to keep the historic window. Elizabeth, did we, did everyone get to see that poll that you put up or do you want to tell us what the result of that was. So we have a lot of professionals with us here today and that's, that's great so, and a few of you that may have a little less technical information experience but we'll hope that that we can augment that a little bit with what we're going to talk about. So that's, I appreciate that thanks very much. So let me get out of that. So let's get started, then with with cultivating our sense of what, what is appropriate. Today we're really going to look at the possibilities for replacement from what is available from major manufacturers, primarily for wood hung windows but also steel factory sash and even steel residential windows to some extent. So this is with repair of. You can create match, nearly perfectly if you spend enough money on it, it's, it's almost always possible to match the window, but that doesn't mean it's always going to be reasonable or cost effective given your project. So it's in that middle ground that most of the projects fall, they're not going to a craftsman who's going to make something exactly like what was there, stick by stick, or weld by well, we're dealing with products that are readily available. And those products vary and incredibly amount on incredible amount when you start looking at them with any kind of care. It's also the fact that we really are asking more of our windows than what the original windows did. It's one thing to, you know, to replace a single piece of glass. But if you put, if where that single piece of glass was we're now expecting to put a three quarter to one inch thick piece of insulated glass. Even the craftsman that's struggling to match that window exactly is going to have to change something to fit that glass in there. So, increasingly, you know, we're having to make compromises to meet the needs and the expectations we have for our windows, and trying not to alter too much the way they look to historical. So we'll look at some basic questions here, but one, how will the window be installed, because that's something that I find, especially review commissions. But don't ask, even surprisingly here in Washington DC, a city that hasn't quite a staff doesn't always start with that most basic question of, are you going to take the old window out, or are you going to put the new window within the old window. How does the material that you've chosen for the replacement window affect the appearance, different materials have different appearances but they also affect the way the windows constructed, and a lot of other aspects more than just the visual quality of the material. And then, of all the things that make up the appearance of the window what what parts of that what are those pieces that matter most. So I have to remember to keep on my little arrow down here. So, here's a little start to get us to challenge our observational skills. I would expect every one of you could look at every one of these windows and tell me why it's not a good match for a historic window. And now when we don't have a historic window, we're going to be looking at what is the basically the typical a generic version of what the window would have been in the building, based on what the architecture tells us. So even if we don't know what the window was we still have a pretty good idea what a window should be for a particular building. So I would hope that that all of these solutions, if you recall in that here are ones that are pretty obvious everybody as to what the problem is and why these are not, but not as good as we could get if we're dealing with with with a replacement. Now, here are four windows that I live in Capitol Hill in Washington, and we row house neighborhood and so there'll be five or six houses in a row that are exactly the same. And it provides a splendid laboratory where you can see all kinds of themes on variations on a theme. The window on these are all four from a row called Philadelphia row. The left is the original an original window that an owner has managed to hold on to. And the next three are replacements. Now, on the surface maybe they all look like pretty good replacements, and I'm not saying they're adequate or inadequate. But I think we need to look at them a little more carefully and we both begin to see how what those differences are. And so when we're shopping for a replacement window we can decide to the does do these differences matter in this or are they ones that we maybe could do a little bit better if we chose a different model or ask for some different features. So we'll return to this a little later but this is I think this is not quite as easy as the first slide to see what's wrong with all these windows or what's not quite as on the mark as it might be. So let's start by just looking at the basic parts particularly of a wooden hung window. We have the sash, which is made up of the rails the horizontal and the styles the vertical parts. It's the part that holds the glass. It was a case that window what would be hinge to facilitate opening if it's a hung window it's going to move in a track. It's the dark green part shown in this, and this highlighted in this photograph and it has a dimension for within a certain range, you know, they're the surprising the little variation in the size of these pieces, at least relative to one another, just across a whole range of windows within a given time frame. The next piece which probably doesn't get enough attention is the blind stop it's this little narrow piece, it's what keeps the wind the sash from falling forward into the street. It's often the cover of the weight box if these are counterbalanced windows. Maybe it's a fun fact I don't know that not that I was asking one of my colleagues why it's called the blind stop and since she didn't know I thought well maybe it's worth pointing that out for everybody. And it is because if anyone's read on 19th century. Things about architecture you'll see that what we now call shutters were most typically called blinds. Well, the blind stop is the piece of wood against which the blind closed, it kept them, the shutter from hitting the sash itself it's that little strip of wood, against which the blind closed and which holds the sash in place, but it's the little, the little punctuation point between the sash and the brick mold or if it was a frame building it would be casing. The shape it can be flat, and of course if it's a frame building it's going to be a flat board, or an ornamented board in some cases but rarely. And as you can see now highlighted here. If we look at if we just step back, we sort of see we have basically from the, from the siding or the brick to the window glass we have a three step system we have the casing or the block or the brick hold. The blind stop which is just a little offset, and then we have the sash, and the sash is relatively similar in size to the brick mold maybe a little bigger maybe a little smaller depending on the application, and the blind stop is just a little narrow piece just enough to catch the shutter and keep the session place, so we have a proportionality that's established for traditional window. The sizes themselves may vary the proportions generally don't vary a whole lot. Now let me go back and look at that slide again. We can maybe see a little more clearly that you know all three of these, all four of these windows have a brick mold. And they all have a blind stop but in some cases the blind stop is gotten like on the third one over. It's super wide it's wider than the sash. And then the sash in the second one, it's gotten super narrow, it's not any wider than the blind stop at the head. So, when you start to look at the pieces and think of them relative to each other, you start to see like why these windows may, maybe they don't look that bad but if you really look at them closely you're you're going to realize like oh yeah that's a replacement window, even if you don't realize it's a replacement window. And then the one on the right, the brick mold is a completely different shape. There's proportions are maybe a little bit better. Some of these are wood, some of them are clad. So the materials may, we'll see may have affected how they turned out as they did. So let's talk first about materials. Windows can be wood, aluminum, aluminum clad wood, they could be vinyl, fiberglass, steel, but how does that affect what we get? Well at the very basic level, the finish of the window is going to matter if it's a wood window versus an aluminum window which is very commonly used in a lot of commercial buildings. And these are the windows and both of these pictures may have been perfectly fine at the 10th story of a tall building in terms of matching it from what you could see of the details. But did anybody think what this window would look like in this gloriously paneled office here? I think not. And maybe you could paint it brown and get by with it, but the material can matter if the inside of your window is in an important space. And in many cases, you know, if you're a homeowner or the user of the building, you might want the inside of your building to look a little better than have a glaring shiny white aluminum or a white vinyl window filling that opening. Heavy drapes I think would be called for. And even a window and a painted wall, then the enamel of aluminum finish is not going to look like a paint finish, nor will the finish of a vinyl window. So all these are factors that just in terms of the most basic level of material that start to matter. But material matters in more ways than that. This is a cross section of a typical wood window. All of the red lines reflect dimensions that are fixed for the particular model you've chosen. Many companies make more than one model. But if you want that sash to be a little deeper at the top, they can't change that for you. You know, you're stuck with that particular dimension. And if that dimension relative to the other dimensions isn't quite right, you either need to go look at another model of theirs or go look at another brand. Those red lines, those are not things you can customize within a manufactured product. Even the depth of the blind stop, which is the blue circle there for that particular window, that's the size of the blind stop. Now, the width of the blind stop also is fixed, but what you can change in a wood window is the brick mold that's just apply it doesn't have to come from the manufacturer you can change it. And you can use, and if you don't like it there, that makes the blind stop look quite wide, but you can move it down a little bit and then the blind stop has gotten more narrow. But that's about all you can do or you can just use a whole different, a whole different molding for that. Steve, I'm not sure. I hope you are not having your screen blocked by the bar that's across mine at the top, I think not. So your options are somewhat limited in the wood window, you just have to look at a different brand if you don't like the window you have if you don't like the dimensions you have. And here's another brand and you can see in this case, the blind stop is way deeper. And it's depending, you know, where this brick mold goes, you know, you could affect that the proportions of the rails and styles are also different. The meeting rail here is a little narrow. The top rail is a little deeper. And it's going to have its own change but it's a little bit like a whack-a-mole in the sense that, well, you know, this one over here we really don't like the proportions of the meeting rail so we'll go find this one but then on this one we have some other thing that's not quite right. So don't expect to find the perfect match in a manufacturer, you know, that's why we're talking about all this being compromised which is, but if you don't understand what the choices are, and what the visual impact of these different pieces is, you know, you can't make a good decision and make it relative to what you're choosing. So all this, it helps to just have at least a beginning understanding. And then finally, a minor detail but I never saw a putty that was shaped like an OG curve or a bead, putty is struck with a putty knife that has a straight line. The manufacturers seem to think it ought to have this shape over here. Usually they do have an option that it puts it back at this shape over here where it's actually a straight line. And the difference between these two units, this one the glazing with the glass went in from the inside so the bead holding the glass in is on the inside. This one the bead holding the glass in it's on the outside. If it's an added piece like this the manufacturer should be able to change that to a simpler profile. This is a photograph I found the other day and forgot I had years and years ago we had a project in a state that where they were not keen about letting people use clad windows. So we thought, well, okay, we'll let him use clad windows on the second floor and we'll let him use wood windows on the first floor and we'll see if we can tell any difference. Well, the second floor is clad and the first floor is wood. But the differences are not because they're clad and they're wood the differences are because the proportions are completely off and I'm not sure either one of them is actually a good match for the, for the the original, but all this is close to the point that material is no guarantee of quality of match, you know, a wood window for a wood window 30 years ago that probably was a useful standard and it may still be if you're in a review commission and you don't have the means in a small town to dissect this stuff and pour over this drawing compared to that drawing and tell the owner like oh no go find another brand. So for a wood window you're probably going to do better than if you get a vital window, but say wood window over clad. Well, really, I don't think the wood window in the bottom looks any more like a traditional wood window than the clad window does at the top. So it's just a reminder that the kind of simple solution to getting a good window is just not there. For a lot of windows and increasingly popular because of the need to not wanting to or the desire not to need to paint the window. And also the dilemma that we do see a lot of wood windows that modern wood windows that have failures that seem often premature or those sometimes I'm not sure that they're kept as well painted as they needed to be. But a cloud window has a different aspect that is not just a wood window with cladding or with the sandwich of aluminum. A historic wood window has the it's shown in yellow that what would be a brick mold that you can apply well the cloud window has where that brick mold would be just a little narrow out of half inch wide piece of the frame that comes all the way through and you're sort of stuck with that. So you can add to it, but it's not it's not the size of shape of a brick mold, and you can't take it away so you can't take it off you have to work with it. If you're going to try to design a case save or a brick mold to go with it. So here are four section drawings through four different clad wood window units. And you can see the piece that I'm talking about is this piece right here. It's where the brick mold would be, and you could add something to it that's what this little notches and most all of these, but you're going to whatever you're going to add that's still going to be part of it. So you have to work with that piece so a cloud window does sort of change the the the strategy you have to getting the trim right. And this is also a good place to notice that how different the shape and dimensions of the blind stops are in these four different models, one's very wide and thin. Another one's not quite so wide. Here's one with an extra step it's like a more complicated frame. And this one has a funny little bump and maybe this kind of disappears a little bit against the sash but none of these look quite like the simple wood window that we looked at in the early picture. And these cross sections here this this shadow line that's running down here and running down here. That's where this groove is that something snaps in to give us a full trim piece. And so now if we look at the next slide here. This is a clad window with a trim piece added. So with the trim piece added that little narrow line becomes this line right here, where either a strip of metal that was an accessory that come that you can order from a selection of shapes from the manufacturer gets you the effect of a brick mold of the appropriate dimension of this little narrow piece, as we saw in the first slide they are the clad window where you just disappears and the idea these windows were made to maximize the daylight opening so you have extraneous trim we don't have weight boxes to cover up it's all internalized into the frame. So there was no if you're building for modern construction that might be a good solution but if we're trying to match a historic window we usually need this trim piece. Some have a flat piece like this. That's just a single thickness, some are three dimensional pieces that snap in different manufacturers have different approaches, and you can get different shapes. This is actually a really great shape to mimic what is a typical brick mold on a 19th century late 19th century. It's not really Victorian building, but it's a really terrible solution if you look at the fact that the dimension of it is over four inches why well a typical brick mold isn't you know less than two inches from here to here. So, if you stick this piece into that little groove, you'd have something that's not 4.4 and 330 seconds you'd have something that's more like four and a half inches or even larger than that, which is way too big for what should have been a brick mold for that for a window so there are a lot of options out there in the in the wood industry but everybody makes different ones and different sizes so sometimes if the if the size and shape the brick mold is important that may drive what you're actually you go to, and you can get these custom made but for it. You're typically adding an upcharge of about $10,000 which if you're not buying 100 windows. That's hard to spread out over the cost of 100 windows in terms of getting that special shape but a lot of times we see people that just do a piece of wood or a sec or something and notch out the back of it and apply over it but then we still have a piece that needs a different finish and doesn't match the finish of the window. And if we have a wood window we have an even more complicated problem because we they make pieces that like this piece here that are three times as wide so it seems more like a piece of casing. But then you're dealing with all this is enamel aluminum. And you're putting it into a wood building where everything else is painted wood. And that may be a not a very bold difference but the difference between painted wood and the perfection of an enameled wood finish is going to be a little noticeable on your wood building. It's a lot less noticeable that everything is all one finishes in the case of this masonry building and there's no wood to be seen so there's nothing to compare it to so you don't realize how different it is from the painted wood finish. But, you know, cloud windows do have accessories from a lot of the manufacturers that allow you to mimic a casing as you might have might have found on a wood building. Illumina windows are a whole different ball wax on an aluminum window in its basic form, the part that is thoroughly the window is drawing on the left. You can see there's no blind stop there's no brick mold, because the way the aluminum window goes together it doesn't need those pieces it's all about the pieces that are locking. And where there is a piece that needs to overlap it's it's in piece of metal. So, in some respects, the aluminum window offers a great deal more flexibility, because you're not stuck with the book, the blind stop being where it is in the sash. A lot of what looks like the sash is decided by where you place those trim pieces. So in the middle photo in the middle drawing here we can see a particularly appropriate shape brick mold blind stop extrusion that's all it's made to be one piece, and the window snaps into that, and it's the set back here accommodate set. Now that. So, aluminum window, this is an aluminum window at the bottom down here it has really great sight lines the top rail is about the same as the styles in terms of dimensions the meeting rails not too flat. So we've got lugs on here that look reasonable and then this is a kind of of all an accessory extrusion that mimics the blind stop and the brick mold all in one piece. But even these pieces, you know different aluminum companies are going to have different choices and if you're only buying 10 or 20 windows, you may need to choose from what they have because you're not going to be able to afford to have to make one for you. Big project that's another matter. Another thing to think about in terms of these limited windows, if you look on the inside of the window up here, if you look at this. The glass is pushed way to the towards the way towards the inside so that they can get the maximum amount of so they get a party bubble on the outside, you still have a lot of space left for a big piece of glass so that you can get good thermal performance. So there's nothing left on the inside for a mountain profile of any distinction and we'll look at that a little more with the mountains later, but the the aluminum window defers to the wood windows, try to compromise and give you a little bit on the inside and a little bit on the outside making those a more popular choice in a home where somebody really cares that the inside, you happen to have mountains that they don't look like they're a flat strap of metal. But the aluminum windows, aside from the issues of strength and everything else. So the way they're made gives us different choices and different solutions relative to the proportions and profiles we can get. When we're replacing steel windows, 99% of the time, they're getting replaced with aluminum windows, you can still buy a steel window. Steel windows are still expensive and they don't generally have a thermal break in the frame the way the aluminum window does. The historic windows on the right, the replacement aluminum is on the left. This one wasn't as complicated as some where the vent is is suspended in the middle of a field of mountains, but still, though this is not necessarily the, these are not necessarily the exact profiles of these windows. And that, like, a typical size we might expect for the, for the rail here that where there's the vent the piece that opens is with a with a aluminum window might be close to two and a half inches. The original steel window over here, that would more likely be closer to an inch and three quarter or even less so this piece here that facilitates this window opening is now much wider and then this is also much bigger because this window opened on a little pin, literally just a piece of a steel stuck in the center of the window and into the frame. Now we have to have opening arms and a lot more hardware involved in the way we know open so it doesn't go flapping in the wind or something that you can control it with an operable. But overall, the difference, the extra dimension that was created by this from here is not, is not enough to make the window look like a different kind of window and then at the top where they didn't need to. They can fake it. So it didn't have to be quite so heavy though it might have done well to make it a little heavier so that it didn't look so different if we're trying to get similarity between the two. Now let's that we've kind of blitz through materials and some of the limitations and possibilities. Let's look at how you install the window. They're really I think of four different levels of replace, you can replace just the sash using the existing operation system that you have whether it be a spring balance or play or weights and police. You can do a sash replacement that involves a new tracking system which is was is a relatively inexpensive approach that allows you to put in slated glass in. And that would be the second level up but you keep the existing frame. Thirdly, you could take that the parting beat out and put in a whole new unit with that's designed to sort of snug up behind the blind stuff. You can put it, then you're putting a frame within a frame. And finally, if you take everything out of the opening that's there now, and put in a whole new unit designed to put it a rough opening chances are you can get the best match, but you're having the most disruption. So let's look at each one of these just a little more detail in the pros and cons. If you're going to just replace the sash. You really the jams need to be parallel and plump, you can't if they're bowed, the session isn't going to fit well so you need to check to make sure that the frame is worth putting a new session. Even if the windows out of square as this one was, you can accommodate that by ordering the sash a little bit bigger and a little bit of carpentry you can play in the top in the bottom and redo the weather stripping so that the sash actually meets the size of the opening if you're using a wood window. The sill needs to be good enough that it can be repairable. And if you're willing to fuss with the weights, you can actually use an insulated glass sash, which is what the cases of this green window here. Those are those are new sash would insulated glass but they're hooked back up to the rich to the police which just were augmented in order to facilitate operation and in a more improved the thermal performance of the window. The rails in the style should be able to match exactly though if you're doing insulated glass, there may be some limitations to the size of the size of the meeting rail. And if the window is out of plane though this is this is a sash pack on the left but you can see how out of square the opening is. Well these were wood windows I don't understand why the craftsman that put them in wasn't more of a craftsman because the weather stripping that was underneath this window could have been pulled out. So if you're going to plane this window to match the angle of the sill, we recurved for the weather stripping and put it back in and you had a much better fit because weather stripping is not designed to accommodate gaps of over a quarter of an inch when one end is fully compressed. So, even, even a new, a new sash, and even a sash pack or as they sometimes call them, accommodates, accommodates out of square units. So the next level that using the the sashing track it that one of the most major manufacturers of this particular solution just recently ceased to produce it, but there's still several companies that do. Now it's no guarantee that that your proportions of rails and styles are going to be the same as what you have now it's just like with anything else each manufacturer offers a different set, and you have a different set of dimensions and proportions so you need to look at them. You know, jump going down this route to make sure that the variations are not greater than you are willing to tolerate for the window. But one of the biggest negatives is that you have a vinyl track. And if the vinyl track isn't a light colored window like the green window on the right, it may not be very noticeable and even less so the window were even lighter. But if you are determined that you need to have a dark window that vinyl track will become very noticeable. This is the way all new windows were made if they had a new window from a manufacturer would have a vinyl track exposed now mostly they're they're producing ones that are covered so that you're not seeing that vinyl and protecting it from the UV allows it maybe to last a little longer as well. But the advantage to both the first solution on this one is the trim on the inside remains in place there's no disruption to your interior. And if you have to start casing on the inside. You've got to keep it we don't have to worry about carefully taking it off and putting it back. There's a good positive, you know, that's a really positive aspect from a preservation point of view. And because it because you are replacing the friction surface. The new set you're dealing with a new sash operating against this vinyl track so the friction points, you no longer have paid done paid where there's, and if there's lead paint on your window, then you're, you're reducing the risk of lead of lead and getting into the environment from this. The sash for these things can be clad or can be would, if you need to be trimming the sash though you need to order a woodwind not a not a cloud when are you going to have that gap that I showed in the previous photograph. The next level up is the insert. This one is a little more popular when the openings are out of square, because I sort of observed that most contractors seem to have a dearth of carpentry skills and they know how to use a caulking gun but not how to use a plane. So of course, planning the window to get the planning the sash to make it meet the opening. That seems to be beyond their capability, but they can fill that gap with a caulking gun so if we have a whole frame that we're using and the windows a little bit out of square then it's easy to make a good fit. It allows us to use up to keep the trim on the inside, as with the other two so we're not disrupting the interior, but we're sticking a frame within a frame so we're adding another layer to this whole system. It can be a reasonable compromise to make and if it's done carefully like the window on the left. The, the amount we see there's the original brick mold as there's the blind stop and then you see this little hairline, and that's where the new part butts up tightly to the old blind stop. And that's a really good fit and it's it adds a little extra bump to the blind stop and then there's another, what really functions as a blind stop now is this next little line down here, which is kind of thin and small. So it doesn't have to be an intrusive element. It depends on the unit you've chosen and the way they've chosen to do it. It doesn't have to be made out of wood of aluminum clad wood fiberglass windows end up doing this though fiberglass usually doesn't have quite the same sight lines and often they have other funky aspects of them because they're not really designed for most manufacturers are not really trying that hard to make them look like wood in the first place so they have different features often bottom rails are too narrow or other things aren't right but sometimes they have their applicability on a secondary elevation. The composites are used there's one manufacturer that that has a whole lot of windows that's a composite like a polymer with wood fiber that the windows are made out of that that is designed particularly for this application. It does increase the complexity of the frame a little bit, but we'll look at some more pictures here, and you can see how, how much or how little that might be. The right are both clad inserts, and you can see the blind the brick motor blind stop are still there, but then you have this little projecting line which in the previous slide we didn't see it projecting like this. And the reason is that if we look at the, this is the manufacturers section drawing of a insert window or pocket window, and you can see how they're telling us to install it. Here's the face of the sash. And here's the blind stop. Well, if we look at the historic drawing on the left, the back of the sash should meet the back of the face of the session line up with the backside of the blind stop, which means that's where this yellow line is that's where the face of the session. We got this way because they're assuming you're installing it in a modern three and a half inch stud wall with a half inch drywall on the inside, and there's not room to move it back, but most of us are and we're dealing with these replaced windows and start buildings the walls are systems are thick enough, but there's no reason this window can't just be pushed back so that this, this edge here is lining up with this here, in which case, if they had done that with these windows. There's no channel of shadow line around here, it would look the window would have been back where it belonged in the original installation. So, here both of these are really fairly decent because they have portionality the top rail is about equal to the styles on the side and meeting rails not too heavy. And we didn't add a whole lot more dimension to the system if only they had pushed it back a little into the wall system, we would have had a whole lot better installation. And that's, it's not that the problem is not the window the problem with somebody knowing how to use it. Because I'm sure that wall was deep enough. Sometimes though, depending on the unit. We lose that proportionality, like if you'll note, in this particular model from the edge to the glass is two and five sixteenths from the edge, from the edge here to the glass is to an 1116 and that's sort of what's going on in this window where you can see the width of the style here is a lot more than the width of the rail at the top. And when we were looking at those, those drawings of a typical historic window, those dimensions are usually much more much more closer in size than they are in this window. But if that's the worst thing about this window, maybe that's okay for your installation. I'm going to be informed that this is what you're getting and you can decide up front like is this where I want to make the compromise or maybe I want to make it someplace maybe someplace else is going to matter less. But you have may have to look at a few before you decide which one, you know you want to marry. A lot of these inserts though end up. I'm not sure if it's just carelessness or what really the solution how they actually install them that we end up with what we end up with. This turret here has an original window in the bottom, very typical sight lines for a traditional window and a replacement in the top that clearly is an insert. So if we zoom in on this is the section from up here brought down to compare to what's going on here. So, even looking up here and here you can see the glass got a lot smaller. And why did the glass get a lot smaller, because what we had is three simple steps to the glass now in about five things so I'm not sure what all they saved and what they didn't when it's a little hard to tease apart what actually happened, but this is what you can end up with an insert if you don't choose carefully and install it carefully. It can be a good solution, but it really makes this window look kind of clunky compared to what we had here before. And here's one where I think in these rounded surfaces it's the the openings may be tapered towards the inside and that may be part of the problem, but I this one you know if they had just thought about the paint. They probably it wouldn't have hit you in the face so much because they painted the sash red, which means the sash really is a miniscule dimension. And the blind stop, they painted the dark brown or the dark gray with the trim. If only they painted the blind stop the same colors the sash, we might not have noticed that there was no sash and a whole lot of blind stop, not to mention the fact that the the original wood frame and the original blind stop that the brick mold and and original blind stuff are all remain in place in this nice little transit bar, but the window they put in. It's really just a little too small it needed to go back a little assuming that there was that they could have adjusted the jam to do that but maybe the jam was tapered and that's why they didn't but that the paint didn't do them any favor at all it just makes clear the deficiency that they chose. It's interesting what some people decide is the right thing to do. And sometimes aluminum windows are used as inserts especially our large commercial projects. These are aluminum windows set within the original Frank wooden frames. It's not something you're going to use a house typically, although sometimes on secondary elevations we do see people do that. And that would be a solution that again says the disruption and more mostly I think it's driven by the fact that it's cheaper that the the owner doesn't have to get rid of all that framing that's in there and and install new two buys and then they're not having to put a trim piece on their on their aluminum window but if this were a high rise building I wouldn't want to have to get up there to paint all this brick mold and blind stop when I have an aluminum window that's that doesn't need to be painted so I'm not sure what the value of that is. And finally, we'll get to the full unit replacement, which I think gives you the most opportunity to get the best match possible, but you still have to choose the right window. Wood clad aluminum can even be I mean fiberglass I suppose is an option. It does disrupt the interior you have to take the trip off on the inside well if you're faring out the walls and gutting the interior then what's the excuse for not doing a rough opening installation, because a piece of brick mold can be matched pretty easily with wood and off and generally with other materials. If you look if you do a little shopping around, and it has this has the best potential for a really good match. And here is a taken from that building we looked at earlier. Here's the historic wood window. And you can see it set back from the edge of the brick about an inch. Almost always set back a little bit from the edge summer set back more than that can depend on the thickness of the law can depend on depend on the intention of the designer. If you look at that same row of buildings. It's set completely flush. This is all the way out to the very edge of the opening. There's no reveal here at all. And it changes the way we perceive the window. And in this case the whole windows pulled out because this brick mold on this historic window is kind of deep so that the glass is well back from the face of the brick. And here this apartment building though it's not a high rise. The walls look thick enough that it could be. And it really makes a huge difference in the way you perceive the building but you know this is a building looks like it has real substance to it with walls that are that thick. If you look at those windows out in the process of replacing them towards the face, you might solve any leakage problems that are still if you have them but you would have changed the character that building substantially. So it does matter where you put it in the wall just like with the insert. In terms of the way that works with the existing trim, even when you're doing a rough opening replacement you still need to pay attention. There's a paint line on the brick that shows you where the brick mold was and so you can work your way back from there and there's no reason to ever come forward of that with your call climb for your new window. It should go without saying that you need to fully fill the opening and clearly, you know, given who you all are listening to this the one on the left is there more for a laugh and anything else like sure nobody thinks that that's acceptable. But the one in the middle, you know, it's only about an inch and a half off. You know, you can order these windows are not, they're not my standard sizes anymore, almost every window is available that you could order the exact size you need. So I don't know, of course, not when they changed the brick mold from what the original was on the right but there's no reason that window wasn't just another inch and a half tall, because otherwise it's a pretty good window. You know, the brick mold is not the right shape but the blind stop isn't all that much too big and the sash has the right proportions, but like how sad to have just like cheated and, you know, for the sake of getting another inch somebody measured wrong perhaps. That's not unheard of. Sometimes it's not just about fully filling the opening, but appropriately filling the opening. The brick mold runs around the curve of an arch. Sometimes though it doesn't like the one on the right, it goes straight across and the fill is above the brick mold here the one on the left is replacement window the fills below the brick mold, but in the end. I hope you all can see like the this little crescent it's just a little too short the corner of this window shouldn't disappear into some shadow. This is a more appropriate installation here where the window, the line of the window goes all the way into the corner not up behind the corner. This window, whoever decided what size to order it, ordered it just about three quarters of an inch too tall, and then it makes a very awkward joint here. But just as just a reminder that that you need to look at what the details are you have and how the often the paint line is a good indication of what you had. If your window had brick has brick mold up here then it should stay up here if it had it down here then you leave it down here it's going to depend on where the brick mold was and how the window works with that with that for the trim. And it would be the same for casing on a, on a wooden frame building you need to pay attention to how the pieces fit together initially and not change it up when you've got to replace it. Arch top windows aren't always what they see. Sometimes the sash is actually arched like the four units on the right hand side of that draw. The sash takes the shape of the arch on the outside, which means the jam the head of the jam has to follow the line of the arch. That's a little more expensive to make because you're having to curve that piece of wood. So for these two whether they're like numbers one and four or they're like one of the other four over here for these two windows. This one. We can be sure that this is not the arch the jam was not arched because we now have a replacement window behind it. This one tells me that the original window looked like number four below. And that was a very common way to make an arch window. The brick mold and the blind stock were arched, the glass was arched, and this and they mask the brick mold and the blind stock mask the corners of the sash. So on the inside, you had a rectangular opening with trim on the outside that faked to being an arch. And this this was fairly common this is a catalog from the 19th century. And we can fit. If you know you just need to know what you have and follow it. These are going to be a lot less expensive to reproduce than this is over here because you're actually having to curve the whole board itself at the top. And here's a window that is clearly like a number four. But because they used a track system, which we can see here, there's an awkwardness at this point when the transition from the blind stop into this track. You know, you can tell this is not like just, it doesn't have the clean lines that this one has as we at the spring point of the arch. So it's possible to reproduce this we've even had this done in aluminum, though, more than once they've gotten it wrong the first time to try again. But it just requires a little precision often you need a template to in order to get that right. But they're not always what they seem to be when we're dealing with these arches understanding that. Now let's look at some of the individual pieces, rails and styles the frame the frame relative to the sash trim components in their placements muntins millions and trances. Some of these variables that you may not get them all right but let's, you can help you can decide for yourself which ones matter most in your particular window. The window on the left is a building from the very first year of the 19th century. It is a super refined, very, very delicate window the the the sash is very narrow, the brick mold is very narrow, the muntins are very narrow. It was probably made from really fine wood that had straight dense grain and they could make all these pieces without them twisting and warping and everything else. The window on the right is a more typical late 19th century window with the kind of proportions we see there. We were not usually replacing a window like the one on the left. If we have one of those old enough that stuck up that survived long enough, it's probably just going to be repaired, or it's been replaced with a really a craftsman made unit we're not trying to sit back through in a manufacturer product, it just wouldn't be possible. The window on the right though, there's a pretty good chance we can do a good job with with a little with a little bit of compromise from a major manufacturer. But we still don't always get it right. The one on the left. If you look at the head, the, the, both the blind stop and the, and the top rail of this are about half the size of the style and the blind stop on the side. Why, I don't know, but that's, that's how that window comes and you can't do anything about. So if that bothers you. It was made because I it looks like the window got shoved up into the top of the frame. It's just, it's not right. This is a historic window in this top half of this bay window. You can see better of course what's painted two different colors, but you can see better the kind of relationship between the rails and styles and the whole thing is about equal to the size of the brick mold around this around the outside, given that they had the right window up here. You can see what they did down here or why, but you can see how jarring it is when you start to change those proportions, especially, even if you didn't see it against this window. I think we'd all be like, what the heck, why do we have so much wood over here for this, the styles on this rather modest little window. It's just not, you know, it was, I don't know, I don't know any manufacturer that makes a window like that so I don't know how they ended up with doing that. The aluminum window, as I mentioned before, what is the apparent size of the sash is often dependent upon where you put the trim pieces, the pieces outlined in red. They're applied sometimes to the frame and before the window goes in and then sometimes they go to the window itself depending on whether the window is being installed installed from the inside or the outside. But we, I often get a drawing for an aluminum replacement window that looks like what I have on the screen in front of us. The leg of this piece of trim sort of limits where, how far, you know, I look at this, I just want to push this back a little further because we have a two and a quarter inch wide style on this window. The visual, that's what we see, that's what it looks like the style is going to be. Well, that's a pretty wide style, anything over two inches is, unless it's a giant window is unusual. It should be close to what the dimension is at the head. Well at the head it's only inch and three quarters so it's a half inch difference between this dimension and this dimension. And there shouldn't be more, there should be less than a quarter of an inch difference there for a typical window. And if for a particular window we would measure it but if we don't have a window we would still want to keep those dimensions relatively the same. So in this case we could like maybe we could pull the window down a little bit from behind there. And sometimes what's necessary is to augment this frame by adding an extra piece and a lot of aluminum companies on some of their windows because they're not putting metal in there they don't need for installation that's not pleasing the historic profiles. So they're not, they're not throwing metal away, but if we need more we can extend this so that if this pulls down a little bit we could make this an inch or two and a quarter by adding a little more material up here, but we can't always add it in half inch increments or a quarter inch increments so sometimes then that will affect the trim piece that we choose and we may have to find a trim piece that has a little more space here that allows us to move that one way or the other because these are the way this trim is designed as a clip here this clips into the window was pushed in from the outside. You could choose a different piece of trim though, you know, in this case the trim has a longer leg. Does this match what the historic is that we need it might, because overall, both of these dimensions are a little great if we add all this up we have for five and a half inches from the glass to the frame which is almost twice what it probably needs to be for a typical trim window. So the aluminum office is this flexibility, but within a range because each piece has its limitations on how it fits together. It can get a little into the weeds with this but usually if you have a window supplier, they understand this kind of stuff up there in a market where they've done historic projects and they can help you find your way through it. The meeting rail is really pretty important in terms of its size because all the other stuff is solid against solid, you know it's dark brown against darker white, white, it's all, it's all massive the edges. The meeting rail cut slices through space. So you really see whether it's big or it's small because it there's nothing to mask it. And I just love this particular example is from Near Eastern Market in DC. The builder of this window was intensely optimistic when they built this window they had great faith in their wood and the design of that meeting rail but probably over over a little too long because somewhere along the line somebody had to come in with a remedial effort to hold it up even with a single sheet of glass there's a little tyron that you can see there that's not the cord from the blind. That's keeping that meeting rail from sagging. And if it had not sagged I would have been truly surprised that we know that the width of that and this is not stretched with Photoshop that's just really how big that would how why that when it was, but it's wonderfully appropriate to a kind of Romanesque effect for that for that little row house. But it can go the other way pretty easily historic window on the left replacement window on the right, that meeting rails big enough, that window could have been twice that big and it would have been okay, but if you're choosing a major that may be the size they make the meeting rail there I think at least one company that does offer had off for a while offered a choice and I think they just finally reduce the dimension altogether. That you know for for all the extra framing around the edge I think that that hits me in the face more than than the extra framing around the edge, and I happen to go by this building when they were installing these windows and the reason. If you look at the top the brick to glass left to right, but not much different on the sides, though the reason it's this different is that when they were installing these windows, they took out the jam at the head. They didn't really need that to nail anything to these aren't very big windows, but they left the jam at the sides. So these windows are kind of a cross between a rough opening at an insert. They just use the jam that was there took the trim off and and used it as a nailer for their new windows which is why the frame at the sides is about twice to why. Again, you know, economics have tried to do it on the cheap resulted in a window that's a little bulky at the frame, but the meeting rail to me is a real, a real negative in terms of the quality and character of those windows. A lot of windows of have the meeting rail has something more going on and let's look at the drawing in the upper right hand corner. If you can see that I hope I'm looking at my own face in that spot so I'm hoping you all can see that. There's a, and if not, I can't move it there so the glass for the bottom for that meeting rail. It slides into a slot. It doesn't sit down here. It's hidden in a slot up there. Nobody makes a window like that because we're not putting an insulated glass into a slot that's, that's cut into the window, but the sidelines for these historic windows were very much different because there was nothing, there were there was not the, there was no offset between the, the meeting rail the upper session meeting rail of the lower size they lined up at the bottom edge, all three, like these windows, you can see there's a you're seeing part of the top rail of the bottom sash underneath the bottom rail with the top sash. Now, is that the worst thing in the world, and it's in shadow, it's probably not the most noticed, but it is a feature that when it starts to get very big, you do start to notice it starts to make the whole meeting rail a little bit wrong. You can see here what we're talking about. In a historic window, you'd have this profile that's up here. And if you can't see that I'll go back to it later if it's blocked by the way the screen is showing the bottom rail, on the other hand, was almost always wider. Pretty much universally wider bottom rail than any other piece of the window. So we've got three to aluminum and one fiberglass of typical of what some of the configurations are. Some of the aluminum companies are finding starting to clean up this profile. We're getting, you know, there was often a little complexity the way the thing went together this was actually part of the frame not part of the sash that this fit down into this, I don't know. I'm not sure why it was this extra bit here but that's a lot we had that for a long time and then here. This fiberglass window which is particularly bad in terms of the meeting rail up here has a bottom rail that's that's exactly the same size as the meeting rail up here so clearly that's proportionally off. But that being said, it's not right it's not good if you're looking straight at it, but in a lot of buildings. Well, I can see the bottom rail here, but I really can't see it here, and I can't see it at all here. And then this building by the time they get to the third floor, I can't see any bottom rail, and even on these aluminum windows that are replacing steel. I can't see the frame at all at the bottom. So, in your palette of things that you can play with the bottom rail may not be right, but if you're dealing with a building of any height. It might not be the most important thing to be worried about given the way you look at the window and where you see the building. You just need to take into account the context in which you're using the window as to what pieces you're going to see most, but you're looking up at the window so you see the head and you see the underside of the meeting rail. The complexity here wasn't right you might notice that more, but because like if you just look at this one to how narrow house how slender that meeting rail looks and it only can look that slender because we're unlike the the previous unlike this if you're looking up at this you'd see a lot more material. It does really matter the on some situations whether that's there or not when you're looking dead on and allow wise building like this one, the fact that it gets buried into shadow makes that less important. Here are the details. A lot of times we put logs on windows because the, you know, they were there. So we want us, we think of them as being decorative certainly notice them. But they get tapped on and maybe if they're done well that you don't notice this joint from a distance. I put it the lungs are very much merged into the, you don't see any joints, but oh my goodness. What did they, you know, the log is the least of it in a window that goes from this. This was clearly a deep frame that stepped back a great deal but it was very narrow you look at the head it was only like a half three quarters of an inch wide. Three and a half inches up here, before we get to this window that's set in there so you know you, you went on one and you lose on another you have to decide which is more important I would say give up the log if we'd have gotten a window that that was more appropriately filled the opening. So let's look at that detail a little bit more. There's a reason those are there. They're not there for decorative purposes. That's a piece a stick of a style, the piece of a style with the, with them on mortise cut out to accept the tenant of the bottom sash. The reason that's there, it was just a way to sort of finish off the edge, rather than just make it a blunt cut. All this material down here gives strength to that joint. If you pull on the bottom rail of that top sash. You're wanting to pull this out, which is exactly what's happened on this window over here, where when you have an open mortise intended. If there was no material underneath this joint. You're more likely to have this happen when it fails it'll fail this way. So this was a sign of a quality window. Usually you'd find it on on better sashes on better buildings more often on an inch and three quarter window that an inch and three eighths thick sash. Though we might choose to replicate it now when we're matching it. There's a reason it was there. And it tells us something about the quality of the building the quality of the windows that we're in that building. And it was an extension of the style. So the last thing we want to do is highlight the joint if we're tacking it off. If we're going to fake it we need to try to fake it as well as we can. And sometimes we don't even try it seems like here's a drawing showing the log. It's not even all the way out to the edge where it might be. So on this on this sample window over here. It's a little better in terms of alignment but you can still see the joint. And then there's some manufacturers that choose to radius this edge I don't know whether what exactly the reason is if it's to accommodate the cladding but even their wood window does that. So there's no way you can tack something on here without having to groove or curve there so that in some cases that that leads to something that looks like this. And if you're going to have it have to set it back and they set it back even more and then if you have a window that needs that there is a tilt function, then it can't be all the way out. I think it's great that this manufacturer can do this, but if this is the best you can do just leave it off. You know you have it, you've called attention to a feature that you that should be seamless and merge into the window. And if you can't do it well, it's the kind of thing you probably best just not doing at all. It's not that critical. When windows are joined, the piece that connects them is called a mullion in most windows, most would windows that we're dealing with from, and even some holocaustic windows from the late 19th or 20th century. And that is the width that is is because it had two sets of weights inside. It was the weight, it housed the weights for the sash that that allowed the windows to operate. Now, later when spring balances were used, they started to be used quite early on we do sometimes find narrow windows and the building across the street from our offices here in Washington at GSA. So the chains go up through the head of the window and go across the top so they are very skinny mallians in the center but that's not that's not the rule, there are exceptions. So there are two ways that that mullions work in general you have the brick mold running around the whole of the opening. And the mullion is a cap set atop the blind stop that dies into the base into the brick mold. And the alternative is in this window where the brick mold goes around each individual unit, and the mall cap sits sort of behind between the two pieces of brick mold. So you have two different, two different general approaches to how these lawyers were done. And there's nothing wrong with the windows down, well, the windows are adequate down here but it's nobody thought about the fact that this is how we'd install the window today because we don't have anything to put in there we don't have any windows. So why make your, why reduce the glass. Well, if you want to match the window up above the window that this one replaced. You need to widen it out a little bit, run your molding around so that you have a match, because this looks very different than this. And it's not something that's hard to fix at all. Any window can be made can accomplish this with a little thought and somebody thinking ahead. This is a window that went through design review someplace and clearly nobody was paying any attention. These are aluminum windows I think aluminum clad windows, and here again this is where the molding runs down along the edge and the, and the mall cap is set between but we still have a width that was, even though these don't have weights, they have a width that would have accommodated weights. So this is the configuration that usually has this the first gray bar is the blind stop. Generally it's the face of the weight pocket this is what's going on inside there, and then the mall cap the million cap sits on top of it and that's what's going on in this way window here though this is narrow enough one might wonder if this is either a single hung window, or I have seen windows where there's a single weight inside a pulley that operates both sash. It's sort of a double, it does double duty with a single weight with a different set of pulleys on the inside. So the millions are always exactly the same but if we don't know we'd expect it to look like the drawing above there. This would be an aluminum window that might come into our office first pass, where they put one slap one piece of metal over the top but you know it has the two steps just like the perimeter does. So it can be fixed just by putting the second piece on so that we have that equivalency. This is happening to be a different unit but you know you just have to look at these pieces and make sure these are details that are so fixable. It's not like it doesn't matter whether it's a wood or aluminum window. There's no reason we can't get this. And one thing though with aluminum windows we have to pay attention to and I thought, Oh, nobody is that clueless, but I just looked at a window the other day for when aluminum window where they had it was a three windows in a row, and that had two dimensions and the dimension on the assuming this is the brick side not the mullion you know this over here might have been two and a half and this was inch and three quarters, it would look like the window it was off like somebody had shifted it out a lie. Somebody needs to look to make sure that this dimension on this side matches this dimension on this side. It's amazing how easy it is for this stuff to go arrive you don't look at it which is why I just I know it seems like a lot of minutiae here we're going through but there are a lot of details to pay attention to that in order that you don't get a window that looks kind of screwed up. It doesn't necessarily mean it's more expensive but those dimensions that red lines. They need to be equal on both sides because that's what it looks like your sessions and we're trying to. We're trying to make it look like it's the real sash. Now now and then we have some distinctions in the mullions they're decorative and certainly, if they're this elaborate you really want to try to hold on to them because they're going to be expensive to reproduce that something like this even you could reproduce if you needed to better if you don't need to, but it adds a real distinction to the window and those kind of details you want to hold on to that there's nobody that would think that those are things that we want to give up if we don't need to it can be a little more complicated even the mullions because the trend of sometimes the windows were it was a separate frame that was stacked sometimes it was made as a single thing with the transom bar mortised into the frame. And the transom sash can be in the line of the upper sash, or it could be in the plane of the lower sash it where it sits in the window system can can vary it's more often than not at the forward most played, but it's not absolute it can be different. And the details can be just any number of things the two on the left. Our historic windows that wanted the green one is really quite ornamental. The one in the middle is a little simpler with just a sort of the brick mold running around the bottom, then usually there's a little bit of a lip or something that allows the water that hits on the the transom to drain out over the whole thing so we're not creating a cult joint where we can actually create mechanical drip. The window has been replaced and they saved the, they saved the historic transom at the top, but then I'm sure this is not the historic detail we just lost it beneath this flat board here. An unfortunate given that it probably, it may not have looked quite this ornamental but I'm sure it was not this boring either so transoms are much more. There's a lot more planning and a lot more care to get them to come out right if your window includes them so that we don't end up just without blocks stack box with a little faceboard over the top that was called into place. Millions of our, what do I say about millions, a lot of review commissions like oh, no fake money, no fake mountains I'm sorry, we're done with millions of no fake mountains. And that's all well and good if you're happy to have it's a no insulated glass because if you want real mountains and you want to slate a glass, you're going to have a mess. You're going to have a wide there for that mountain. It's going to be a lot, a lot wider, unless it's a, maybe a late 19th century two over two window, you probably can have two divided life for that and get away with it but for a six or six or nine over nine that there's no way to make the month and thin enough and still hold the insulated glass unless you're using one of these new vacuum seal really thin units. What are the issues then in terms of what we're getting with these mountains which are typically if we're going to fake it it's going to be a simulated divided light SDL is the shorthand for what we're talking about and that means a grid on the out a three dimensional grid on the outside, a three dimensional grid on the inside and a spacer. Well that if this is an aluminum window that grid on the inside is going to be a flat bar, and you don't have any truck that's the best you can do a wood window. You know they want to give you a little on the inside a little on the outside but the result is the little on the outside is often too little. The thickness of the sash. You know we're not thinned down the the the insulated glass too much it often gets pretty shallow. And sometimes this is an example, the drawing at the top is really what this window is down here. Instead of a putting bevel we have a beaded profile for the perimeter as well as as the mountain. So before I've never seen putty that was beaded it's usually a flat surface so this is not really the right profile this is more an appropriate profile, and the window over here is closer to that though it seems almost more squared and trapezoidal. Minor details but this is one usually we don't have to we don't have to settle for the one at the top, usually you can get the one at the bottom if we ask for it. The material you've used for the window though will affect what you could get typically an inch and three eight sash which is a tip thickness of the sash for a historic wood window. The depth of that mountain on the outside is going to be three eighths of an inch. That's how deep the putty bevels itself. If you have a thicker sash an inch and three quarter or even up to two and a quarter on a monumental window. Maybe a half inch or even up to maybe as much as seven eighths of an inch that depth. Well that's a pretty deep. A pretty deep mountain. And how do we perceive the depth of that mountain, it's because of the shadow cast, you know, we're not nobody's going up and measuring it. But if it's a deep mountain it's going to cast a shadow and it will you will notice it if it's too flat. A modern wood or clad wood window, with one exception of one manufacturer present that I know that a major manufacturer. The depth of that mountain is only five sixteenths. It's only half of it's a sixteenth of an inch shy of what the inch of what a typical domestic window would be with a three eighths inch bevel. So it's a little shy but maybe a sixteenth of an inch, not so bad. You have a thicker sash though. The wood window industry and clad industry is not going to serve you well with that month with again with one exception, at least for now one exception. There may be some companies that smaller companies that can give you a little customization for a up charger not starting from scratch that you're having really a shop built unique window. When it comes to the mountains that when you have a mountain grid that's just too flat, it's going to sink your whole effort to make the window look historic. And it may it could be the driving force to the window you choose, if you really care about the way the window looks, aluminum manufacturers can do a little bit better because as we saw before, they don't give you anything on the inside. So they have a little more room to play on the outside. So some are as little as five sixteenths. But more often you can get seven sixteenths you can add another eight. And there are a couple that are now giving you that can provide up to a half inch deep mountain on the outside. This is the illustrated with the, with the drawing down here of the cleaner line for a sash for a newer model of a one of the manufacturers where they really have nine sixteenths so there's room for a half inch, a half inch on the surface of this window, which if you had windows like this over here in the Department of Agriculture building. Those mountains are way more this is this is a profile of a mountain for a deeper window well you know you can't have a month on this deeper than the frame around it. So you have, you have to start with with something that's a deeper frame. Maybe, maybe a half inch would be good enough to match it if it was seven eighths, but I assure you that five sixteenths is not going to be good. That we're just not going to be able to do that with that with that window. And those would be reasons maybe we have to look at better to be looking at it really trying to hold on to those windows and using a storm window for not going to spend the money to do the replacement in a way that doesn't make it look feeble and and shallow and flat and fake. We all know we don't want just space, we don't just want, and these by the way are not true STLs because they don't have a space or between them as they would be, if we would expect an STL now to have. But you might, you know, when the, when the mountains are too thin and too feeble looking that they're just not going to be convincing. And the mountains are everything when it comes to the steel windows. Steel windows had a whole range of profiles, historically. The T bar on some. Sometimes we have a flat, because a lot of steel industrial windows are putty from the inside in a factory where windows would get broken more readily of stuff going on, much easier to be able to replace the glass from the inside and I have to get a ladder and climb up decided the building to patch that window. A lot of times the profile on the outside is not putty. It's either a flat bar in some cases which is virtually impossible to get on unless we're doing 100% faked grids, or more typically a double concave, which is the profile down here in a simulated site. And some will just give you this, but now when you look at this window, and I'm we're relatively close I mean you can tell it probably has this profile, but would it be that different if you looked at this profile. You know, think about, you can look at this stuff in great detail, but from the standpoint of where you look at the window, how much of these distinctions are you going to see. You can see that I perceive the overall width, but how much will you perceive that shape. If it's right on the sidewalk and your nose up to it then yeah it's going to matter. If it's on the second floor or 20 feet from the sidewalk, maybe this is not something you're going to notice in terms of the shape of this you will notice the width of it and it's probably it's depth. So, this is like a typical kind of drawing for an aluminum window where you might be widening out one of the one of the mountains in order to fake where the vent was. If the vent doesn't have to be operating. The original building on the left had steel windows. These are the replacements for them on the right. So, the, the sight lines are pretty darn good. Some of the vents were deleted from the original because there was, they were not absolutely uniform and regular and they didn't need everyone to have it so like we, some of the, some of the vents in the center pieces were dropped. But these are all the vents that are here are all are all operable then these are not fake these are windows that actually open, and they are that they are that delicate. So, this is done with a window that was a, it's not truly thermally broken it's thermally of crew, and for some projects that might not be good enough. But it's a company that does provide us probably the best narrow sight lines for mimicking these industrial steel windows. It may not be applicable, it may not be useful in every application, but it, it can be, we can get a very good effect from the new windows here. Then, more than what we might have gotten, you know, 25 years ago or something. This is more typical of what we were getting where that the mountain on at least four points. That aluminum, aluminum is not as strong as steel. That aluminum needs to be wider and heavier enough to support those operable vent here, because the rest of these mountains are all fake. If they weren't fake they'd have to be a whole lot wider and a whole lot more expensive because then every one of these little pieces, every one of these pages would be a single piece of insulated glass and insulated glasses you probably know is charged by the perimeter of the square edge. So the more edge you have one more likely it's going to fail get more more edge to fail, more edge sealed failed but the more likely that then the, you need to have a wider month and behold it and the more expensive the whole system becomes so typically what we're getting for these industrial steel windows are simulated divided lights with true mountains where we need to hold up something. So, unlike the previous picture where this was a little bit narrower. This one's a little, this is the one in the previous picture that was probably an inch and three quarter for that this mountain here. And this picture, it's probably closer to it. It's closer to, it's a little bit bigger, I don't know what, maybe closer to closer to two inches for this dimension here, and this is a lot bigger as well. You can do almost anything if you want to fake it. And these are windows where the vents are just are false. They are there. And then because they're, they're wider the way the historic ones were, if we look back at this picture you can see, you know the extra lines here, even more so at the top and the bottom usually because the windows were never fully closed and they're pivot, but you can see that we can get. And if you don't need the windows to operate, you can do a very good job, a very good job of getting the profiles here you need only even the glass gets so big that we need to have some true mountains to divide up the glass because it's just too big a piece of glass. And you can still get a steel window this is a new steel window. And has this nice narrow side lines them. All these mountains are true mountains so that it's no problem to hold up events that occur here. It doesn't have any thermal break so it's not going to be, you know, you still got to have some conduction through the frame, even though you still windows can be made with insulated glass. Now, and many are in higher and up situations so we just don't usually have a rehab project that's willing to spring for the cost of the steel window. So we end up with having to figure out ways to make those compromises to either fake these vents where we don't need them to operate so we can get them closer to the original profile original dimensions, or else, you know, just try to keep them at the absolute minimum. And, and given that their companies have increasingly improved their product over the past 20 years in terms of this kind of window. So, some of the ones that were as good as we could do 20 years ago are not are not ones we need to take anymore because they're several companies that now can do better so is we not jump the bar. We're getting. It's easier to get a good match for this kind of window as manufacturers rise to the occasion. At the domestic level usually first deal with what we're seeing as a case and these can be really difficult and just impossible to get quite a good to match on these. If you have a three part like this. It's a little easier because the center one doesn't need to operate so you save some space there but clearly the width of this sash overlapping the fixed is nowhere near as narrow. I mean it's it's way way narrower than the original than what it is here with the replacement. This is about as good as you can do. The only thing else that we lose is that, or that that's a noticeable change but maybe not immediately noticeable is how much narrower this line is up here from these two here. The difference over here is not very great, but aluminum is not steel. And if you had two of these together. You know you couldn't have two operable windows side by side the way you would have had it in steel window and have the same profile so for these kind of for these sort of windows when we need to go to aluminum. We really are looking at compromises and trying to figure out you know just what's the best we could do and maybe you don't have to have more than one side open on on a given window. If you didn't, if you had just to to sash instead of three. Didn't do that. Forget that arrow. Get rid of that. Press the wrong button of the project on the left. Those are aluminum replacement windows at the top and original steel at the bottom. So when the windows kind of small. The montains are well matched. It's pretty good match. I don't think anyone would would notice right off hand other than the color that those windows were not the same and pretty successful. The project on the right though, where the steel window had almost no depth to the jam which is simply not possible aluminum frame is always going to have a certain like three inch or two and a half to three and a half inch depth. In the corner you cannot make that dimension go away. So the replacement windows compared to the historic windows in this particular application are nowhere near what was there before and are and are a pretty dramatic change in the character of this building. And it would seem to me that one should have thought very long and hard before deciding that this was necessary to do, given that that this is such a fundamental design concept for this window that to change to this. And if we did look at it, maybe they should have been looking at a steel window. I don't. I have an occasion to explore this steel manufacturers to see how close to the original could they come with a modern steel window but clearly there are some places where a substitute material just cannot yield what I think would be even a remotely acceptable solution. And another examples of where of how those corner windows are just particularly critical to the character of these properties from the mid century, and not something that we have a good solution for it present. We covered a lot of ground here and I hope I didn't leave too many of you in the dust, or confuse you. Let's just look at a couple summary things here to kind of remind us why we're looking at all this. These are from like buildings similar row houses in a row. The original window on the left of the storm window and despite the, the diminishment of the storm window and to the character of the window. We still have it, you know, a nice narrow mountain narrower than usually a two over two would be, you have the brick wall with its original hinges in place. And then we have the replacement window at the neighbors did. They cleaned up the profile. So they don't have a lot of clutter going on between the screen and the window. But what was a pretty narrow profile before is about twice the size now. So, you know, there's all covered with a little bit of so there's nothing to paint, but there's also the window looks kind of meager in its, in its opening, where as the original one, I think was just no, you know, we didn't. We were not successful in any respect in trying to capture the character of this window that this is not about this is not a compromise this is I would say a failure. Here are two that are. It's just really lovely when people do one and not the other because it makes what we're trying to do so much more easy to see. So at first glance, the replacement window on the left looks pretty good the meeting rails a little wider but not a lot the mountains are fairly appropriate in terms of size and depth they don't look flat or shallow. What, what is different here well if we look at the blocks in the quarter and look at the shadows that the frame of the frames the historic window on the left has that very simple brick mold skinny little blind stop and session in a three step down to the window. The window on the left. There's a little more frame, and it's just this wonderful cascade all sorts of steps all the way down. Now, in a overall building with the amount of architecture going on, like this window on the left be an adequate solution, it might be for some situation, it might not be for others. But let's understand what we're getting and what we can see and what we can't see if we stop and think well okay you know what are our priorities here on a window like this maybe it's the month and in the meeting rail. And that we not that the overall dimension from glass to masonry is not significantly greater. And maybe this was one where there was just disruption on the inside mattered as well I don't know what their concerns were, but it's not perfection. If you're good enough, you have to ask yourself what what mattered in this in terms of this window and that we get anywhere near to that. And then finally, this one which I've used for a while. The historic window on the left is indeed obscured in large part by a storm window which nobody really likes but it does protect the window. And the lighting was just bad the day I photographed that. But I would challenge you all to look at these two windows and and you know manufacturers say oh we can match anything well they can match the pattern of the mountains. But let's look carefully and see what here doesn't match. I think the storm window kind of obscures a little bit but I'll just give you the first one is that the new windows been pulled forward in the system. You can see the reveal around the storm it is clearly there's a recess between the brick mold and where the windows gone. Well this window though there's a little gap, it's almost in the plane of the brick mold it's been pulled forward. It's probably some kind of an insert. And then point number two let's look at the mountains themselves. If you look at the window on the left. The mountains at the top are not the same as the mountains on the bottom and the mountain on the bottom. The top ones are quite delicate, very narrow because they're holding little pieces of class. On the bottom, we have a much wider mountain for the two larger pieces of class. If you look at the new window on the right. They're all the same to why to narrow little both depending on what you're looking at, and they all seem to have a little bit of a profile I don't think they're just a straight profile, they're a, they're a beaded profile. Now, this is a good trade off. We don't have to look through a storm window anymore. But some of those things we might have actually done a little better at these are applied. It's in a simulated divided light might we have matched the difference between the width of these mountains a little bit better, or could we have pushed the window a little further back in the open, if we've been thinking about it and not so that and of course then the white paint doesn't help that they're, you know, if we understand what the differences are, then we can decide which ones, which ones we want to push at and maybe which ones we just need to let go for the situation, the economics of the situation, and then the reasons we're doing the replacement in the first place. So I think I've talked enough. I hope you all have had some questions. If any of this is generating any questions we can go back and look at some of these images again. And I appreciate your great patients. Thank you. Thanks john that was fantastic. As always. There are quite a few questions in the chat and I'll start to work through them. And if anybody else has more questions keep keep putting them in the chat. I think, first of all, the several people have have been asking if you would recommend any specific manufacturers for both double hung windows, industrial replacement windows. The manufacturer that does lugs well. So I don't know how you if you feel comfortable doing that or not. Well, I'm not going to recommend any manufacturer because I would say that. I don't think in my role at the Park Service that would be appropriate in the first place but there are many manufacturers that do some things well. There's not a single manufacturer that I think does everything well, which is my point why you, it's a little bit of a whack them all this summer a little less back them all than others. And there's some that they're, they don't do anything well, well, and you should probably stay away from those. But you can tell that when you look at them. The lugs, I would say, are probably the least critical aspect of things I mean they are, you know, they were a sign of quality and you should probably mimic them, but you know, don't choose a window that has a tilt function because then the lugs definitely not going to work well. And don't choose one that has a radius corner because you're never going to get back to work. And if you're choosing an aluminum company you need to, you know, they probably need to make one that's deep as deep as possible to the window some of them choose to make a little shallow one. And then I had a project early on that where they, there was nothing wrong with the one they made, but the guys installed it they weren't installed in the factory they were installed after they were, and they just put it in the wrong place so you know, there are lots of things that are not just about the manufacturer. But there are differences and there are some companies have been constant, there are at least a half a dozen window companies that I have talked to on a regular basis. When they're open it when they're designing a new product or when we're trying to find a way to make a product better. But some have listened, and some have have changed their products in the 25 years I've been working on this we have different products today than we had 25 years ago. And I would say that it's because some of them realize that we are a market that matters. And that, you know, they're not going to give up, they're not going to create something that's really going to disadvantage them in a new building or the industry that doesn't care what the windows look like but they realize that we are a market that's worth, worth addressing, and they have done so. And we have some products that have gotten better. With the steel windows as I point out, we can get the best looking steel window from a company that doesn't make a truly thermally broken window it may have some thermal improved performance, and in a project in buffalo that might matter in a project in a project it might not. You have to weigh your needs and look at these, look at these individually. And if you have a window supply company in larger cities sometimes you'll have distributors that that really understand the parts and understand the components and help us to figure that out. There are some architects that, you know, many of the Arctic seem to be a little awesome types of some of this stuff. And I can certainly understand I mean I look at, I look at this stuff a lot, and it's still like I'm thumbing through pages to be like oh, you know was which is that one and which is this one. And it's a lot to keep track of, and you may have, you know, you may have only access to certain companies in a certain area to so I, you just have to, you just have to make an effort, and look, and look and if there's nothing else to leave it leave you with here is that you need to be observant, you need to be keen observers and the more you look the more you will see, and the more you see the more satisfied you'll probably be. But then maybe the better product will ultimately get when you go to choose to replace something and you think about how you're doing it and then don't turn your craftsman loose. If this is a true craftsman, don't turn your installer loose to do it without paying attention to how they're going to do it because it, you know you can take a perfectly good window and and install it in a way that results in something that's that's a very poor substitute for what was there. So, no, I'm not going to give you a list of what companies do what. But I think it could, you know, like what I was talking about one company makes a deeper month and one of the wood cloud companies makes a deeper month and I think you probably could find that if you looked around a little bit. And if that matters to you, but if you're only replacing an inch and three eight sash in a typical home, you don't need to have you don't need to have so you know it just depends but then that company, the rails and styles are rather too narrow. It's like a window that has great monthings for a big window but they make rails and styles that are truly too narrow for a big window well which is more important to you and your application. So, there's nobody that we can give the gold star to I would say. Fair enough, fair enough. How about you have any thoughts about vacuum insulated glass. It's still expensive though we have had several projects use it a large project large buildings and more are being are coming through and I think in time that will bring the price down a little bit. It is a way to allow us to save an historic window because it's thin enough that usually the window can accept that glazing without much modification. In the past, if we had wanted to put an insulated unit in an existing with sash you had to route out the sash a little bit, often compromising the integrity of the sash. There was no way to have the kind of weeks that that aluminum windows would have or that, and the seals are more likely to fail sooner if the windows sitting in the water. We've had projects that did that that lasted a pretty long time and others that failed sooner than they should have largely that's due to the seals but the seal on the insulated glass now is much better. But the vacuum units are such that they could even be used in a in a multi light window like a six over six window they could be individual units in each window. One side is that there, there's a little button where the dark of a dark button on each particular pain. That's more visible probably from the inside, looking out then from the outside looking in, but it's a compromise that at least our program we have felt was was was more than acceptable, given that we were keeping the window and getting the kind of improvement that allowed that historic window to continue an operation. I think it's probably a more applicable for the retrofit that it is for a new window, but if somebody was trying to manufacture a new window that you know really, we're trying to keep everything very thin, it might have applicability there but right now I think it's biggest burden has cost I think there was actually a webinar going on from a better organization. As we were talking here today about about that glass and you can, and you can find that find those programs pretty, pretty readily I think they're the manufacturer that does that as an English company. If I'm not mistaken, and you can, they do a lot of promotion. So, yeah. Okay, there was a comment but I'm wondering if you might have anything to add about when windows are replaced in south Florida they're required to meet hurricane standards and that it's, it's very difficult technically impossible this person is saying to reproduce an early 20th century window to meet those standards. Any, any guidance that you would offer on that topic. No, I think we just have to accept kind of the best we can do and look around and make sure that we've looked at more than one option for the supplier. Some companies may be a little more sensitive to that than others. And in time they may come up with ways to beef up the, the strength without beating up the section so much. But it does present a problem and a lot of the windows and early windows in Florida and I didn't touch on that much because we were only beginning to see many projects that are having historic aluminum windows. And a lot of those were windows that were in that were really poor in terms of thermal performance they were worse than the seal. They were often not they were economical and often not very substantial in terms of their frames. So, we simply can't get the kind of performance that we expect now the window whether it be strength for impact or thermal resist or impact resistance or or thermal performance with a with us a frame as delicate as what that was. It's just like that. The 18th century window that I showed there earlier on that was real is from the octagon house here in downtown DC. You couldn't, you know, you couldn't do, you couldn't make that window out of anything in a place that was had to have that kind of performance so I think in terms of the standards and not that this talk was about the standards but the approach to the standards has never been to to insist or create a bar that prevents the building being used at all. Well, and sometimes suggest that well you know if you're making an apartment when it was really an office and what you need for an apartment makes, puts demands that requires the window be something more than what it was before that maybe it's the wrong use for the building, but if you can't do anything in the building without beefing up those windows then we just have to have to accept a certain amount of it and sometimes we can, you know, maybe the details, the way it can be the broken up with a trim piece or something we might diminish the effective appearance of something. There are some tricks on things we for a long time we were struggling with the events in the steel windows. Because in the end, it's we look back at that, at that one image I had of in this building. If you look at the historic windows, you see this extra like line at the top in the bottom. When we were faking it was just making a wider bar when we were doing something were false. It never really quite seemed right, because it was all in one plane and so one manufacturer came up the idea with well we together with them we came up the idea of adding a, like a quarter of an inch angle that was attached at the top in the bottom of that sash, where it was a fake sash, so that it created, you know from the ground what do I see I see a shadow line is the shadow line here I see a shadow line here. So by doing that, we weren't really matching it, but we were thinking about how we see it and creating some, some features that helped us to see it in a different way that gave them that enlivened the whole thing and gave it a little more three dimensionality. And I haven't really thought much about the, because I don't look at Florida projects directly. I often have an occasion to look at any to think about whether there are other ways that we might enhance these windows that if they're just getting too bulky to help to break down that mass a little bit but I do appreciate the dilemma and it's one that we certainly will probably be seeing more of it. Like, you know, what do you do with a building that had historical jealousy windows I mean for goodness sakes you know there's some of these are just, there's just not much you can do about it. And you just have to accept something that's, that's basic. Right. Great. So, this question says it seems that Mr Sanders suggests that vinyl is acceptable as a replacement for historic windows. It is often said that vinyl needs replacing after about 20 years would on the other hand can be kept for much longer if maintained and can be repaired in cases of rot. Can you comment on that. Well, I don't remember if I said vinyl isn't appropriate replacement for anything but in the end it's not the material itself that we're looking at but what can the material yield, and I get to see a vinyl window that has profiles that has a putty bevel even you know I vital can be a higher quality material and a lot of windows of very high quality in Europe are made of vital. So I just, I don't think that vinyl means that is necessarily bad but what we, you know if you look at a cheap aluminum it doesn't look very good either. So the fact that these things UV can degrade a lot of things and the finishes. The finishes on some of these materials are important help maintaining their long term appearance. Vinyl is not very strong, at least in the windows that we're seeing domestically. Even some of the polymer based things that are that are used for some of the replacement windows, they wouldn't be you couldn't use it on a building of more than a few stories because of wind load of limitations so vinyl is. I don't think we're here to say that any particular window, any particular material is acceptable or not acceptable. And I'm more than happy to look at a vinyl window when the vinyl company makes a window that looks like a wood window. And so far, nobody's quite done that yet now does it last as long. Well, maybe not but I just one of those pictures I had of a wood window. I just happened to notice when I was photographing it that I was astounded when I, and there was a building that is very well maintained. I mean, the window, I could begin to see some rock. And I'm like, how is that is that what no, how is it that we already at a building that, you know, neighborhood where people are taking care of the property and they're painting it. The wood that we're getting in windows today, I mean, almost all the companies at a water repellent wood preservative, but that is noise enough, because we're not, this is a reason the wood people. Oh, this window here. Look at this joint down here. I mean, this window doesn't look like it's been poorly maintained. But that joint has cracked, there's enough of a crack in that joint where the wood is moved differentially that the style is starting to rock already. Right here. The paint is beget will be failing shortly. And that's a wood window. So, I think the argument is a lot stronger with we're keeping old wood windows that it is, if we're replacing with new windows. And, you know, I can't in time I think we'll probably see some other products. The wood is an option that that it's an expensive option but it actually uses an acidic acid to to modify the structure of the wood in a way that not only makes it brought resistant but but dimensionally more stable, so that you don't get the differential movement between this piece and this piece because grain is opening and closing and one's going this way and the other's going this way so that joint is never going to stay tight. The historic windows accommodated that better because the wood might have been, you know, older growth would. But even then, I mean, eventually, anything will rod if you don't keep it painted. So I do think that that would is, it's why people want to cloud window and maintenance is great if you're going to do it. But I can't tell you how many projects we see that, you know, 20 years later, less than 20 years later, we're seeing the same project again and they're replacing the window again. Well, I didn't really paint it well enough or in a case like this, the window which has never been without paint is still with some problem. And, you know, I don't need to want a bad mouth with windows because I do think we get, you know, we can get better details with the wood than we can with the other things but there's a reason why we're using some of these other things. And it's one thing to say you should oh you should go paint your windows you should do a lot of things but you know, do you have, can you find somebody to do it. And that's often that's often the problem with maintenance on any of this stuff. Right, doing it right. Can you comment on working with a large company, large window manufacturer versus a smaller, more boutique company. Yeah, I was like, some of these smaller companies have been very much more responsive we we have. We have one place where we have a lot of small wood fray buildings and where they're not possible to do sprinklers and they're used for affordable housing. And so the windows needed to be egress and the, and the sash wasn't big enough with the double hundred sash the bottom sash to meet the minimum size so we were trying to create a casement and you know if you just have a case with a month and in the middle is not the same as the offset, but working with a small manufacturer we came up with, like we made an overall deeper casement and then then cut back the bottom so that though it was still a casement, we had a real offset in the glass was moved a little bit at the meeting and you know, one of the bigger companies wouldn't have seen that as enough of a market that they weren't going to mess with it but the smaller company did and it's it's something that it's their region where this window is needed. So they were able to do that. And I've talked to other companies where I said, you know, like, you make the same thing that a Marvin appella Colby whatever makes. I'm asking you to change one aspect of that window to because I maybe I want my meeting where I'll to be deeper or something. What's how much more what I'd like to spend over your regular price for that. If we just, you know, make some modification, and their answer was about 20%. So if you can find someone of a scale that's still a manufacturer and they're not making these one by one at a shop, then sometimes you might be able to get something tweaked a little bit, especially if you need, you know, 50 windows as opposed to five windows. If you need five windows, maybe you go to the shop and get them. There are smaller manufacturers out there, especially in the wood industry that can do that in a little bit of not so much though, you know, every now and then there's some quirky person that comes out of the woodwork that decide, you know who that is. You know, you have to do something, something bizarre, and they can pull it off. But yeah, I think I think it's if you have a special need, something that's a little unusual, then certainly go to a smaller manufacturer and talk to them. If you have several, if you have several windows that you can, enough that's going to make it worth their while and you might, you might have some good luck, but you will, you still will pay a little bit more, but maybe not as much as if I go to the craftsman who's going to make a one off windows for me. You know, there are craftsmen out there that make beautiful wood windows and probably, you know, use better wood than the average number two, or the average plantation growth pine or whatever. And for the, for the carriage trade industry and they're gorgeous, but they are very expensive. And that's, you know, I don't see them in a rehab project that comes off across my desk. Um, you talked about a lot of the examples you showed were masonry buildings. A question came about buildings that are wood, where you have an additional wood sill detail added on top of the historic wood sill. How do you address that. The sub sill on the wood window. That can be, you can have like wood windows in a wood frame building up a two step like in the wood in the masonry buildings we have looking at in front of us. The, the sub sill is the stone in a wood building there's a larger piece that goes out. And that can be, that can be added as a lot of manufacturers can provide that as an option. It can be something that you're set in place in the, in the wall system and then install your, your window, your standard window on top of that. It's going to be an issue for your, your craftsperson to do that to get that right. A lot of those sub-sills are worth much thicker wood and you may have trouble with the options that the manufacturers offer you for that sub-sill to do that. The casing then usually terminates on top of that. So the ears, if you could order it, you know, you have to, you have to know what size though casing is that you're putting on it so you know how much, how much longer those ears need to be than the window itself. But yeah, wood frame buildings to present a unique situation. And I didn't even mention that in the, in the Northeast, there's a whole class of windows that we don't see anywhere else in the country, or at least I've seen in the in Maine, in New Hampshire, Vermont, in Massachusetts, that don't have a blind stop. And those windows surely were built in place. The casing is the blind, the casing's what holds the windows in. And when they have shutters, they're on the face of the window. But we can't, there's no replacement window from, no manufactured units that is going to send us a window without, without something to hold the sash in place. And it can't be side applied casing. So we usually just end up stacking it up and pulling the casing in a little bit. It makes, puts the window about three quarters of an inch deeper in the wall. And there are regional variations on some of these things that are, that are quite interesting. I'm not quite sure why. Clearly the window was not coming from a, from a factory then if the session was not held in place for shipment, they may have bought the sash from the shop and then built the window in place on the site. And we see windows that don't have any, I've looked at older buildings, you know, pre civil war era buildings that don't have cheaper buildings that don't have weights. They have a thick piece of wood for the, for the jam and that's just it. So if you, if you go to take the window out of the opening in a brick opening, you don't have the offset for the way the weight pockets that give you a place to put your nail. So, you know, we have, there are lots of variations, more things that we can cover here today and this sort of general thing and I don't want to get lost in the weeks completely. It does make it makes it interesting for the, what we see these kind of variations and they present each a unique problem when we're trying to match a replacement. Right. Well, we're getting a little long on time so we've got one more question. A lot of communities, as well as folks going through the historic tax credit program. You know, the standard for replacing windows is often about the documenting condition being deteriorated and beyond repair. Do you have any guidance or can you point to any guidelines for how to determine the condition of a window. Like I said, that's another talk really. I think you're really. If it's just the sash or bad then why are we replacing the whole jam if we can replace the sash. We need to look at that. And, and sometimes that is the case, but usually the, you're going to find conditions are worse on the west and the south. Specifically on the south because the sun is more is the is not our friend when it comes to deterioration. And you want to, you want to look at the pieces of wood that you're using if you have to, if you fill all the cracks, and you have more surface that's epoxy than you have would then that's a good candidate for replacement. What is really critical, I think that often overlooked is the importance of the stability between the, all the pieces of the jam and the where that fails most often is where the, where the jam, the vertical piece meets the sill. And if, and that was nailed together put together with a mortise joint usually before, or a rabbit joint before it was put in the wall, and that's how the windows box the frame is assembled. If it's failed and the jam is not going to be held true and plum to the sides and your window may not fit equally as it moves up and down. So if you're, if your sides are not true and plum if they're spread a little, and the reason they might be spread is that joint is you can stick your, your pen knife into that corner that's usually the place the first place I would look to see if there's integrity to the frame itself because if there's not integrity to the frame, you know, the sash don't matter the rest of it doesn't matter you need to have solid stable frame and maybe the frames being held by the casing on the inside and brick molding on the outside but it still should be all four pieces should be well attached and I think talking to, though it's hard to find a window repair person but if you can talk to the window repair person, what would he have to replace if he was repairing that window, and if you have to replace a whole stick of wood. You know, you're probably looking at a similar price to replacing the whole thing. Oh, great. And I know john that there are a couple questions have come up that could be their own session so hopefully pass. We'll do it again next year. So great thank you everybody for tuning in this afternoon and thank you john again for the great. Thank you all for your patience and attention. Yeah, thank you john so much this was incredibly informative and detailed and I can tell by the response from the chat that there is a lot more interest in this topic so we'll have to follow up on how we can include some additional information and resources in the next year. Thanks to john thanks to Elizabeth, and a quick reminder to everyone else that if you're interested in an additional post conference workshop will be joining our friends and colleagues from the National Park Service again next Tuesday at two o'clock for another workshop workshop on amending national register nominations. So thank you to everyone for attending. Thank you.