 Okay, it looks like we have critical mass, so welcome everyone to today's webinar. I'm Jim Lindberg with the National Trust for Historic Preservation. I really appreciate everybody joining us for this session, which is calculating carbon savings from building reuse and retrofit and the numbers that keep going up we've got great interest in this topic we had over 600 registrants signed up and I see it. We're pushing 300 now online with us so I know a lot of you are looking forward to hearing from our expert speakers on this exciting new tool that they're developing to help us. Calculate carbon savings from the work we do to reuse and retrofit older buildings. First I want to start just with a couple of housekeeping notes. You're going to hear a lot. I think of interesting material and I'm sure you'll have some questions so please use the Q&A function on Zoom and we'll answer those questions at the end of the session we'll have about 15 minutes or so for Q&A. Meanwhile, as many of you are doing feel free to use the chat to communicate with the other participants on the webinar. Also, we have closed caption available for this webinar that you can enable that or disable that either on the bottom of your screen or through your audio settings on Zoom depending on the version you're using. And then finally, yes we are recording this webinar which I think will come in handy because you're going to get a lot of great information and I'm sure many of you may want to review this or share it. So the webinar will be recorded and then archived through the National Trust Forum webinar library. Next slide please. So before we get to our speakers, I wanted to let you know that this webinar is the first in a series of webinars on this topic and others to follow organized by the preservation priorities task force. And if you haven't heard of the task force, the PPTF is a collaboration between the National Trust for Historic Preservation, our National Trust Advisors, and the National Preservation Partners Network which represents more than 100 local, state, and national organizations around the country. PPTF came together in 2020 with the goal of working collaboratively among organizations to address some of the major issues that are facing our preservation movement today. So with volunteers from the trust and PPN and others, a group for working groups have organized to address priority issues that include affordable housing and density, diversity inclusion and racial justice, preservation trades and workforce development and as you're going to hear more about today sustainability and climate change. Next slide. The goal of the PPTF is is again to work collaboratively and in a coordinated way gathering examples case studies from around the country, aligning our messaging developing new resources, all really to help our movement to grow to evolve and to become more effective than ever before. Next slide. So where each of the four working groups organized around those four priorities developed issue briefs that summarize some of the challenges and opportunities related to these priorities so take a look at those if you haven't had a chance to. Next slide. The briefs and other resources about each of the four priorities are online at the PPTF website, which is preservation priorities.org. And that'll be another place as well where you can get to the recording of this session. For example, each of the working groups is also developing additional resources this year, as I mentioned case studies, model policies communications tools, other resources that we hope will be helpful and useful to the preservation movement broadly across the country. Next. So all of this work at the through the PPTF is supported by the Moe family fund for statewide and local partners at the National Trust. Last year, six NPPN partner organizations received grants from the Moe fund to support innovative preservation projects related to each of the four priorities that I mentioned. And one of the Moe family fund grants last year was awarded to the Boston Preservation Alliance in support of the effort you're going to hear about today. And I just wanted to introduce Allison Frazee who is the newly appointed executive director of the Alliance, and also one of our stalwart members of the sustainability and climate action working group, just to say a few words about this project before we hear from our speakers. Allison. Great. Thank you, Jim. I'm thrilled to be here today as a partner in the creation of this new tool. I'm Allison Frazee the executive director of the Boston Preservation Alliance. The Alliance is Boston's leading nonprofit advocate for historic preservation. And for more than 40 years we've been protecting places preserving character and promoting vibrancy throughout the city. Until last year we've been partnering with colleagues on the sustainability and climate action working group to promote the understanding that building reuse is climate action, and working closely with local environmental advocates on examining the true cost of demolition to the environment and Boston's own climate action goals. I learned of the carbon calculator tool that you're getting ready to hear about. I was energized by the idea that we could not only put numbers to the loss of embodied carbon and emissions, but use these calculations as a tool to advocate for the reuse and continued use of buildings. As we expand our understanding of what places in our communities are historic. We have found that our tools are often inadequate to protect the places that matter to residents. We want to strengthen our preservation toolkit and partnering with advocates from other fields who share our goals, preserve places in our built environment for future generations, because they're historic, because they tell stories, because they have irreplaceable fabric, and because it's the right thing to do for our planet. This tool will help advocates like the Alliance put real numbers behind something that we've known for decades, the greenest building is the one that already exists. This tool is for developers Laurie Ferris and Larry strain for creating this tool, a mobile family fund for statewide and local partners for supporting its development, the preservation priorities task force for hosting today. And all of you for taking the time to learn more about how you can support this effort and utilize the calculator in your own communities in your own advocacy with your local municipality elected officials, or directly with development teams to produce a true cost proposal that includes demolition of viable existing buildings. So let's get into the presentation back to Jim for introductions of today's speakers. Perfect. Thank you, Allison. Yes. So you're going to hear from two of the developers of this tool. First Larry strain Larry is founding principle of Segal and strain architects, an award winning firm that focuses on community projects and sustainable design. Larry has served on the boards of the ecological building network and the carbon leadership forum and was on the research team for CLS embodied carbon benchmark marking project. He's also a member of the materials knowledge working group and has been writing and speaking about materials sustainable design and reusing buildings for more than 20 years. So delighted to have Larry who will speak first and then you will hear from Lori Ferris who is director of sustainability and climate action at goodie Clancy architects in Boston where she leads research and projects for educational institutions that are renewing heritage practices while advancing climate action goals. Lori is a wonderful champion for preservation as a strategy to help meet climate mitigation goals, and she's active on climate policy groups locally in Boston nationally as chair elect of the IA committee on the environment, and internationally as a steering committee representative for the climate heritage network so again terrific to have both Larry and Lori with us and we'll hear from them and then we'll have a chance to hear from you all so I'll turn it over to Larry. Thank you Jim. So good afternoon everyone it's morning still for me I'm in the West Coast but it's nice to be here. Thank you for having us. We're going to talk about why we're using an upgrading buildings is we think the key to solving the climate crisis we're in and show you this tool that we're developing to make that a little easier. I wanted to point out that we're still on the first slide say the team member who isn't here is Aaron McDade, who's a senior program director for architecture 2030. She's the one who built the current Excel version of the tool that we're going to show you. We have seen this pie chart before showing global greenhouse gas emissions worldwide buildings make up about 40% of total emissions 28 from operating the buildings and 11% from building them. The point we like to make with this chart is not so much whether they're operating are embodied but where they come from operating emissions are almost all from existing buildings. The emissions are mostly from building new buildings. So one way to reduce overall building emissions just to make the ones we already have cleaner, and to build fewer new ones. And you can see from the chart on the right that for the buildings were building between now and 2030 about 80% of their emissions would be embodied emissions from building them. So it's really important to stop building so many buildings and reuse what we got. Next slide. There are a lot of existing buildings in the US they outnumber what we build each year by about 85 to one. So to lower operating emissions, we need to upgrade the buildings we already have to reduce embodied emissions we can use lower carbon materials and carbon sequestering materials or we can just use fewer materials by reusing what we have. And so for building, particularly when you can reuse the carbon intensive parts of the building, the foundation structure and building envelope has a much lower carbon footprint than a building a new building, typically 50 to 75% lower. Reuse and upgrade address addresses both sources of emissions, the upgrade part reduces current operating emissions from existing buildings, the reuse part makes it possible to build fewer new buildings. And also reducing future embodied emissions as well. Next slide. But it's not easy to convince people to reuse and upgrade buildings developers owners and architects I should point out like shiny new things preservation architects like to work on cool historic buildings, but to really address climate crisis, we need to be thinking in terms of saving and improving all buildings. We can't always do this, we're still going to need new buildings so it's not a simple process. We have lots of variables to consider, such as what if you can only improve the performance of an existing building by 50%, but you can replace it with a zero emission building, and how to climate zone grid efficiency and building condition affect these calculations. We haven't had a tool that could compare all of those variables. The care tool compares the total carbon emissions operating embodied and avoided for different existing new and reuse scenarios. It's not really a design tool, although it can be used to make early design decisions. It's a tool for planners building owners and developers to understand the carbon impacts of their decisions and help them evaluate whether to renovate and upgrade or build new. Next slide. The partners in developing this tool architecture 2030 has been involved through Aaron since the early days and when they've recently taken over managing the project and helping us get it converted into a web based open source tool. Carbon leadership forum incubated the tool, and as it provided valuable feedback and support throughout the NCC and climate heritage network recognize the tools potential from the beginning and have been very active support. We're currently working with each DD, which is Escherich Comsy Dodge and Davis and architecture firm in San Francisco, who's developing their own carbon estimating tool called epic, which is aimed more at new construction. We're exploring ways to share the back end carbon data from both our tools that we can then present using two different user interfaces, one for new projects and one for renovation projects. Next slide. There are lots of places that care tool uses architecture 2030 zero tool to calculate operational carbon emissions and body carbon data is drawn from LCA studies from carbon leadership forum Athena, the book residency, a carbon study of the structural engineers Association of California and a number of whole building LCA studies from various sources, including some of our own projects. Next slide. I'm going to walk you through a project in a minute, but here's a brief overview of the tool and how it works. This is what the dashboard currently looks like although that'll likely change when it becomes an open source tool somewhat. You enter information about the existing building, the planned retrofit of that building and the new replacement building. Based on the information entered the tool provides estimates for the embodied operating and avoided carbon emissions for each of those scenarios. Renovation and upgrade options are selected from drop down menus. And you can select a new replacement building from four different building types, and you enter your target operating EUI also the existing building EUI is based on the zero tool based on the CBEX database. Next slide. So these are the drop down menu choices currently for the building retrofit. So each comes with associated body carbon, we have four categories of renovation option structure envelope interiors and MEP systems. And you're what you're doing is selecting the level of upgrade for each category from no upgrade all the way up to major upgrade and complete replacement. And they're usually calculated as a percentage of what a new structural system or a new envelope would be so that that's what they're based on. And that they come with embodied carbon footprints for each of those choices you make. Next slide. The new replacement building covers four typical building types based on size and structure systems not use each with different embodied carbon footprints. You select the one that most resembles your replacement building type. The existing building types are not defined by building use but by structural materials and size which have more of an impact on embodied carbon than building use. Next slide. Operating emissions are based on, you can set your own goals for your replacement building, or your, or your retrofit and the existing building is based on the zero tool. So you have your existing building. E UI you can iterate yourself so you always have the option to enter your own data if you know more otherwise it makes choices for you based on the building type that you've selected. And then you can select how much of an efficiency upgrade you're going to give, or what the new building baseline will be based on what you have so it gives you some choices you can select to make it a very efficient building you can make the new replacement, then the retrofit all the kinds of things you would expect to be taking into consideration when you're setting targets. So next slide and I'm going to turn it over to Lori to walk you through a project. Alright, thanks Larry. Hi everyone. I've shown you sort of the basics of the tool I'm going to illustrate how this works both at a single building scale and also how we can think about scaling this up to look at an entire portfolio and what the applications might be for for planning and policy scale. Next slide. So this building that we're looking at here is a real renovation project and in 2014. It was reused of this historic building that was constructed in the 1950s is a Hillel Center. You can see it's it is contributing to a historic district it's adjacent to a 19th century building divided by this party wall and set third prominently along the Charles River here in Boston. And this was adaptively reused into as a welcome center and admission center for the university. Next slide. So this project was both a restoration of the exterior a comprehensive renovation of the interior as well as strategic addition so there's some new construction components to achieve modern requirements such as a mechanical penthouse on the roof. This addition on the north that both provided more daylight and transparency as well as additional vertical circulation and a new entry canopy that made this building more outward facing towards the campus to suit its function as a welcome center. And so what we what we're trying to model here are those those avoided emissions both the embodied carbon benefits that we're seeing by reusing 86% of the building structure and enclosure rather than replacing it with a new, as well as the operational emission productions that we're able to achieve moving forward by reducing the operational energy use of the building by over 70% through the addition of interior insulation and high performance building systems. So we can look at how this enters into the calculator first we go back to that that general project information that first box and this is where you input information like where the building is located its primary use type and how big it is and this then queries the data within the calculator to pull the climate zone typical energy sources grid mix emissions that kind of information as well as the operational timeline and this is a really important input because this is this is defining the duration of this study. So for example, if we if you wanted to evaluate a project now that you know had a certain reduction target by the year 2030, you could enter eight years here and that would allow you to look at only the critical time frame that we care about and this is sort of different than the whole building, you know, whole building life aperture that we frequently use when we're doing this type of assessment. Next slide. The next section here is information about the retrofit. So here you can see three categories the top is general information again in case the building is changing use or changing size you can input your information here. The middle is about energy and emissions. So this is essentially where you're defining the operational emissions of the retrofit and as Larry mentioned if you if you have information about this. For example, if it's a project that's been built and you know that energy at the end or if you have a target based on energy efficiency, you can input that otherwise you can use default values. And then the bottom is embodied emissions. So this is where you use those drop down menus to define roughly the scope of renovation so for example, at the interior are you just replacing some finishes or is it a total comprehensive renovation with all new interiors. And from that, that definition of your renovation the tool then pulls an approximate embody carbon footprint of your project. And they're similar for similar inputs for the new construction option. So in this scenario again you define the use of the building and the square footage which is probably the same as the renovation. You can again define your operational emissions or operational energy use so this you know might be might be dictated by building code or by zoning or it could be something that you have a target value for or not. And then the bottom again is the embodied emissions, which is the drop down as Larry showed you for those four categories of, you know, typical new construction typologies with substantially different embody carbon footprint. Next, and then it gives you the output so this is one of the output charts for that building that admissions center that I showed you, and you can see the three scenarios the cumulative emissions over that 15 year time period. And you can see both the operational emissions and yellow and the embodied emissions in blue. So if we do nothing to the existing building over 15 years, all of our emissions are operational. And that, you know, reflects the energy use that the building was using before it was renovated. The middle scenario is the retrofit so you can hear you can see here a small amount of embodied emissions from the renovation. And then also operational emissions from performance over time and but you can see that because of the efficiency that is building achieved through the renovation, the operational emissions of the retrofit are much smaller over 15 years and then we've done nothing at all. And then the last scenario is the replacement new building so here you can see a much higher embodied carbon that larger blue bar. We've just, you know, hypothetically given this building a better energy performance just for the sake of argument. So you can see that yellow bar is smaller but even with that improved efficiency, you can see that the retrofit over 15 years results in lower pretty significantly lower total emissions compared to that replacement building. So this is the same information but here instead of looking at cumulative emissions over that duration we're looking at how those emissions occur over time. So here we can really understand and see that carbon payback of the decision we're making here. So the red line is the first scenario where you do nothing you can see there's zero embodied emissions at the at year zero at the year of renovation, and then a straight line reflecting the original energy use of the building. So the green line represents that retrofit scenario with the low embodied carbon, but a greatly reduced slope which reflects the improved operational efficiency of the building. And you can see the green line and the red line cross at about four years. So that means that our carbon payback is is four years the carbon debt of the embodied carbon to perform the renovation pays itself back to improve efficiency within four years. In contrast, you can see the blue line which represents the new building scenario much higher embodied carbon slightly lower slope but even so the green line and the blue line never crossed which is just reinforcing what we saw in the previous slide that the renovation will use well results in lower carbon through those first critical decades after renovation. So I'm going to now show you how this plays out at a campus scale. The tool currently only accommodate building by building analysis. But we're thinking that being able to use a set of portfolio skills really critical on might be a next step in the development but we'd like to show you how you know the type of application this might have. So this is a historic campus outside of Atlanta Georgia indicator. The campus was founded in 1889 and in the year 2007, they committed to achieving carbon neutrality by the year 2037 so they gave themselves a 30 year window Agnes got that's right. Wonderful campus. Okay, next slide. So this is part of a historic district. It's really critical to the historic characters critical to the identity of the college. And so they've taken a stewardship approach to growth over time. And so as Larry mentioned, we will build new buildings there will be growth but it's really about how we approach that so in this case, they chose to reuse rehabilitate repurpose their buildings over time in addition to strategically adding square footage as it was needed. Next slide. So using the calculator, we were able to look at sort of backcast to the embodied emissions, the avoided embodied emissions associated with that stewardship approach to growth from the caught the founding of the college through today. And what we found is that that that stewardship approach resulted in avoided emissions equivalent to approximately 34,000 metric tons of carbon dioxide equivalent. So to put it into more tangible terms, it would take a force the size of the entire campus 400 years to sequester that amount of carbon dioxide. Next slide. And we also use the tool to look forward to understand how we're using buildings had an impact on their carbon neutrality target and their strategy to get connect zero. So what we're looking at here is the same. It's basically showing information in the same way as the crossing line chart we saw for the single building, but here and so the do nothing is the gray line in this case, replacing buildings is the red line and retrofitting or them is the green line. But what you can see here is that when we're looking at an entire portfolio that's all operating and using a lot of energy. And when we look at just renovating building one one building at a time and improving its energy use. It just makes these little ripples in the total carbon profile. And so what the tool is able to illustrate here is that this is a we kind of need both and as Larry mentioned we need to both reuse buildings when they reach that renewal point. And we have to upgrade them in the mean we can't wait for that sort of once every 3040 50 years to reduce their operational emissions. Next slide. Let's look at this a little bit differently here we're looking at annual emissions. So again do nothing is a flat line and gray. There are no change it's just operational emissions the same year after year. If we replace buildings at every renewal cycle you see those spikes and body carbon, and those represent the spikes in total carbon represent the embodied carbon of new construction. We have a dark green line which which is a smaller spikes of embodied carbon of renovation, but the lines trend downward, and that represents the improved efficiency of the entire portfolio over time. But what we're looking at here is that dark green line where which is reflects the actual emissions on campus, which have seen a 40% reduction since that 2007 commitment, and that reflects both the decision to reuse buildings and to retrofit them to high performance, but also implementation of strategies like led light replacement, like working with users to understand habits that reduce energy consumption that impacts the entire portfolio at once. Next slide. And that that both and approach of continuous improvement and renovation at end of life reduces the total carbon emissions in this 30 year window by 41% compared to doing nothing to any of the buildings, as opposed to only 3% if we were to replace buildings at the end of life with net zero construction, and that that avoided carbon emissions here is equal to that same forest the size of the campus growing for over 1000 years. So this is really substantial opportunity and the kind of analysis that the tool can be used to perform to support building reuse and retrofit as a climate solution. Next slide. I'm going to ask maybe Larry and I can both have our cameras on at the same time to talk about next step. We are working on that that single building version but we have a lot of you know ideas for how this tool can evolve over time. Larry, did you want to. Yeah, so the tool does a lot already, and every time we get together with other people working on similar tools we find more ways it could be used. So one of the things we're looking at is, building buildings are a lot of buildings that get reused don't just get renovated in the exact same footprint there's building additions people want more space it gets bigger. So we were adding a separate window for building additions that would be counted as part of the renovation number but it would be, you'd calculate the, the emissions based on new construction and things like that so it's not a function that we're at it we're going to be adding that would allow you to save different scenarios if you're looking at different levels of efficiency of different types of renovation, and then be able to compare those scenarios afterwards to see, you know which scenario performs best. So it's not just about a tool to say should we rebuild, or should we fix up what we've got but what if we fix it up this way what if we rebuild this, you can try different things. So manually adjust emission factors and fuel sources if you know this gives you this draws from sort of the 2030 a zero tool draws from national databases on fuel sources and emission factors for different areas and different building types and if you know more than that you can enter your own data which is good. We'll probably be expanding the drop down menus for renovation options we're still. Those are the hardest ones to get at. If you look at, if you look at the way that embodied carbon is is the data is gathered it's either through whole building LCA studies, which aren't very specific about the different components of the building. They usually just show you the whole building or they might give you four or five different components and that's it. But there's not very many studies that go into specific building envelopes building elements like the building envelope and different ways to retrofit that so those are the ones were. We're sort of parsing that information from all the different studies and trying to do the best we can with that. But we'll give you they'll probably be more options to choose from in the final tool. So how to make this relevant beyond just North America so making sure that the data sources and things we were starting to think about probably won't happen in this first version of the tool. Think about how to make a tool that's relevant to Europe as well. And as Lori is Lori pointed out this portfolio function is probably the one that we're the most excited about because I think that we're recognizing that just fixing one building at a time isn't going to get us there we got to start looking at whole campuses and whole cities and looking at what what a city or a campus might have in terms of their building stock and coming up with strategies to save and retrofit and upgrade that. Okay, it's exciting where we're working with this, this other tool that's that's done very good back end work on a body carbon particularly on the epic tool from HDD and looking to combine our data sources. So we're, we're going full steam we're working with this group and probably will start putting this tool into an Excel based open source tool in a month or two. And it'll I don't know how long it'll take them to build but we think only a few months so we're really expecting this out for the end of the year, but it's been a long process, but we're excited about it. So you have anything else to add to that litany. Well, I guess just to expand a little bit on the data question we. I think is the preservation crowds know the exciting thing about preservation and existing buildings is that they're all different. And so that's part of the, the challenge here of representing at a high level representing what it takes to upgrade existing and historic buildings accurately and so we are continuing to, you know, refine options that reflect preservation treatments in addition to in terms of embodied carbon and in addition to the retrofit options. So that's one of the areas where we're still working with the preservation community. And also trying to perhaps tie in the interrelations between embodied and operational carbon so that, you know, if you say that your building is going to be net zero, you have to include MEP upgrades and envelope upgrades, you have to pay that and body carbon price in order to see those sort of efficiency improvements so that's maybe that's another facet. That's it. I think we're happy to take questions and have a discussion. Great. Okay. Thank you. Laurie and Larry needs to get my camera back on and Allison. You can join us as well. There we go. Larry and Lori, I just want to thank both of you and also Aaron McDade with architecture 2030 I know you guys have been working on this for some time and, and it's a labor of love. I'm sure you have other things you're doing as well so I think those of us in the preservation community really appreciate this and I know that you are partnering with a whole host of organizations that have been supportive of this and I just want to thank those groups as well, you know, architecture 2030 carbon leadership forum, the zero net carbon collaborative and climate heritage network, among others, and Boston preservation Alliance, of course. But I, you know, I just think, you know, we're all going to benefit from this and I think, you know, we recognize that this is complex work and that's the challenge of climate change is that there's, there's so much complexity to the decisions we need to make. Right, there's urgency, and I think you guys are trying to just do heroic work to help us make good decisions and make them quickly because we don't have a lot of time. And, you know, I think want to emphasize to the theme that I think both of you hit that, you know, there is no one solution here and some of us in preservation I know we sometimes are guilty of saying well you know if you just save the building that's, that's the solution, and that's good. But we've got to recognize that rehabilitation itself has a carbon impact so how we go about doing that work matters. Thinking about ways that new and old can blend together creatively, kind of that both and solution that you mentioned and then to think about ways to scale up this work as quickly as we can. There's tons of good questions coming in here so we've got a good 20 minutes or so to get it as many of those as we can and then again I just want to emphasize that I know this is a lot to absorb for all of us so the session is recorded and the slides and the session recording will be available. I'm sending out an email to everybody signed up for this, you'll get links to to where to go to get those so let me just see if there are some questions that I can pose to those of you who want to take them. And I'll just start I guess was with one of the questions early on from Duffy in Flagstaff, hi Duffy about the timeline and just perhaps Larry you've written about this kind of the importance of decision making and you know when. I want to assess the the time factor here. How do you, why do you set, for instance, the calculator at a certain years in the future versus whole life. Help us sort of understand the intersection of these decisions and the timeline. As Laurie pointed out, one of the one of the reasons you want to be able to set the timeline is because your particular in client or institution may have specific target dates they're aiming for us you want to see sort of how you're doing within that target date where will you be in 15 years or 10 years. So that's important. I, I tend to take a more drastic view which is just that we need to do everything right now. We know we sort of. So I almost wanted the beginning to have this time this timeline you could set only go up to 20 years, because after that, who cares it's all too late. So it was sort of this idea that we're not really interested in carbon savings that are happening 50 years from now. So we wanted a tool that that you could set the timeline and that maybe if they're, you know, while there isn't a default but if there were to be a default I would say it's 20 years that's sort of our window to really get to. I look at when I'm setting a goal or I'm looking at trying different scenarios, the one that gives me the fastest payback and then continues to be a low impact building is the one I'm looking for. I'm not really looking for one that eventually will be better. Because we don't have time for eventually. I answer that question, but Lori may have a different take on anyone else want to add to that, you know, this urgency of taking action and having impact appear quickly. I think that's one of the things this tool can help us understand Lori or Allison want to anything to that. I was just looking at the question it was asking for more details about the operational timeline so just from the tools perspective. The way that the tool works is that the it we're assuming all the embodied carbon happens, sort of upfront, and then we're assuming that the operational emissions are set at a rate and then they accumulate over time so if you set that timeline for 10 years, they're getting all the operational emissions, plus 10 years, or sorry, all the embodied plus 10 years worth of operational. And there was also a question about sort of longevity material longevity tied to that. And one of the fundamental decisions we made with this tool is that we're not looking at replacement cycles of materials here. One because they're not really substantially different with a renovation and new construction typically and also because, as Larry mentioned, we're not looking over a long enough time frame for those replacement cycles to be worth evaluating what we care about is the sort of the the state the early stage and body carbon impacts of the material production and construction activities. A person from Amy Barnes asking about how how the tool recognizes that different building uses impact operational energy profiles and how you guys are including that in the tool. Well, we're not currently accept that that the baseline operationals are always based on building, building types from the seed, basically the CBACs database so different building types have different operational typical outputs. It doesn't get into actually looking at individual users of a particular building it's more by building type at this point. One of the challenges this tool has been to both make it have enough detail so it's relevant. It feels like it's, it's not just glossing things over but make it simple enough so that a non non designer and non architect a building owner or developer can input the data and just get a quick take on should I build a new building or should I fix what I got from a carbon standpoint. We're trying to work I were oversimplifying for sure. And we know that, and we're trying to build in ways so you can either more detailed or or accurate information if you have it, but if you don't it falls back to benchmarks and assumptions and averages. And that's really what it's designed to do. We don't want to this isn't really a design tool it's a it's an estimating tool and an evaluation tool for a short course of action is really what it's coming down to. And does the tool include a measure of the carbon impact of demolition. That's it's in a we have a little tab that we didn't show you that's basically other factors that would impact impact the carbon footprint. And finally, we can ask that question a lot and it will probably be in the final version it's it's not a very big number compared to all the other numbers if you actually look at demolition versus building a new build a whole new building. It's usually fairly low but we would like to include that it's hard to find good carbon numbers on that. So what you're really looking at is the, the equipment that's used for over a week or two to demolish a building, you know, and hauling it away that the whole thing. But, but the factors about what happens to the material after it gets hauled away way if it goes into landfill and then it decomposes and releases methane, that's all sort of built into the basic assumptions of just the reuse itself so it's not. So it turns out that demolition equipment and hauling isn't isn't a huge, isn't a huge number usually, but we would like to include it's my my answer to that. All right, yeah. Laurie and Larry and Allison I invite you to chime in and pick out a question here if you see it one in the Q&A that you like to respond to but I'm going to I just there's so many good ones I thought this next one was particularly interesting just in terms of how this can translate to dollar impacts, which is obviously where a lot of decisions get made. What are your thoughts on that. You know, for instance, the, you know, the operational costs. In particular, yeah. We've talked about that we don't have it as a tab yet. I'd love to add that operational costs wouldn't be that hard to calculate based on your area and your energy costs if you you're reducing it by 30% or 50%. And body embodied costs of carbon would only become relevant if you were actually putting a price on carbon, and you could put you could put a price on carbon very low like what the sort of typical government standards are $20 a ton or whatever it is it's or you could try and put such your own numbers so we don't have those yet. I don't think that the only one that I think would be relevant to developers might be the avoided operational the operational savings. Yep. But I, if there's so many places this tool could go. And that's one of them that we get asked a lot that it would be great to have money involved. I think cost is so complex because there's so many different types of money here really there's the, there's the first cost of doing the renovation or the restoration compared to the new construction which is hugely hugely variable. Then there's the cost of energy over the long term which is also variable independent, you know, I mean we can vary databases that you can tie to but that varies a lot. And then there is the potential future cost of carbon or real cost of carbon if you're in a place that has that. So, yes, Larry mentioned we do think that's valuable but it's really complex and I think there are other tools and development that hopefully within the next year so we'll be able to kind of plug into other initiatives rather than try to expand this tool to accommodate that complexity. So an advocacy perspective when I think about cost and thinking about the development timeline, and we know that preservation happens at the local level. So every municipality is a little bit different here in Boston. We often don't talk about whether or not to keep a building until we talk about its historic significance, what happens to be for us at the very end of our timeline our process for reviewing development. At that point the development team has already sunk a lot of costs into their project into their development, their architect everything else, and they don't want to start over and reevaluate whether or not they should keep the existing building. So if from an advocacy perspective we'd like to change the process so that we are doing these calculations and having these conversations about do we keep the building do we add on to it or do we replace it at the very beginning of our development process. So we're making the best choice for that particular site, not only for its historic significance but for its impact on the environment. Yeah, really good. Yeah. So there are a lot of questions coming in which is great and one of the things we'll do is capture those and we'll try to actually respond following up if we can to the individual submitting those but let's take out a few other themes here and one is just the connection I think Laura you were getting at when you talked about scaling this up from individual decisions about individual buildings to perhaps portfolios or the example you used of campuses. What about the, the role of a tool like this in policy making. How could it inform public policies relating to decisions about the environment built environment. So I think there's a huge opportunity there I'm actually curious to hear what Alison thinks about this as well but yeah I think it's just there's been a lack of ability to quantify the impacts of building reuse as we know and both policies focus only on operational emissions, sometimes just even operational energy sometimes we're not even to the point of talking about emissions but even with emissions. So our goal is really net zero and I think what I was trying to highlight is that getting to net zero operational emissions can actually have a huge carbon footprint. And so our goal really needs to be limiting total carbon and having that this type of tool or the ability to to quantify as I'll describing if you tear down a building and build a new building that's net zero, that shouldn't be in compliance with this policy so are there avenues through zoning that require a total carbon disclosure or with our, you know, our carbon disclosure ordinances that we have like local law 97 in New York or our bird ordinance here in Boston. How can we make sure that we're doing this with low embodied carbon so I think this kind of tool can help us can really just enable policymakers to include embody carbon requirements or total carbon requirements because this can help support project teams or owners or planners in, you know, finding those numbers. That's great. Yeah, I think, yeah. Allison, did you want to add. Yeah, I think I always spot on, you know, we, we talk a lot about the energy efficiency and whatnot of new buildings. So when a developer proposes a new building. Oftentimes they'll hire a company to do a study to talk about the environmental impacts of the new building itself the energy efficiency how green it is. And they often don't include what we're losing for the building what's already on the site that needs to be demolished and taken away. So, one of our advocacy efforts is to make sure that the full site the full pictures included in those studies, and then that public information so we can have a dialogue about it and understand as a community what's most important to us and make sure we're advocating for policies that reflect that. And architecture 2030 talks about this is they talk about our timeline in terms of a car, a total carbon budget, what we have left to spend before we go over into sort of what they call maybe tipping points. And if you look at it that way, what Lori is talking about with the portfolio is that it's, it's not just where you get to it's how you got there, you know, is so if you get there by by spending twice as much carbon as another scenario that's that's totally different in terms of the carbon budget we have left so you really are trying to get people to think about the, the total carbon they're spending on whatever project you're doing over the time period you're looking at. It's not the end result it's not where you start it's it's the carbon that's emitted in that time period. And I think that could be used in planning I think most cities don't even consider embodied carbon or the, or avoided carbon in their climate action plants they're not even looking at that right now. Yeah, and there hasn't been a good quantification of those impacts or a way to understand them and I think that's just one of the ways this tool can really start to change the game and what one question I had. You all are building on some data that carbon leadership forum helped gather on, you know, the carbon footprints of different building types and so on and materials. Help us understand perhaps when it comes to decisions about what to keep and what to replace in a rehab, where the carbon intensive parts of buildings tend to be. The easy answer is, keep the structure in the foundation. If you can basically keep that you're you're keeping anywhere between 50 and 75% of the carbon footprint of a typical building so it's huge envelope is then probably the next biggest one, in terms of, you know, if you're, but the way you have to think about what you're keeping it's not what you're keeping it's what you would replace it with that's where the carbon comes in. Okay, you're keeping a bunch of brick, which is a high carbon material that's great but if you would replace it with wood siding. That's not a great so you can't just look at it from the what you're keeping it's what you're replacing with because that's where the new carbon footprint comes in. So, but I but typically what we're looking at for viable buildings from a carbon standpoint are buildings where the structure is basically sound. The envelope is sound maybe you're just replacing windows or just re glazing windows. Then you've got a thing where you've really got pretty low, low carbon new new mechanical systems which we sort of recommend in all cases because of building efficiency. You're probably, I think the CLS study was sort of like maybe your 10% of your carbon footprint is only in the mechanical systems, maybe it's lower higher depending on what the system is but it's not a. Because the payback is really good from a carbon standpoint of the investment isn't very high. So, and interiors typically aren't aren't that high the problem with the interiors is not so much from a preservation point of view but from a TI point of view. They roll over all the time materials get interiors get replaced every five 1015 years and that's where the carbon impact start to really build up. So the other thing you're looking at is to try and get people to build more durable material material interiors or get them to think of me in terms of every time you change tenants you shouldn't just rip out everything and start over again. Right. Design for design for change. Exactly. Yeah, and adaptability. Yeah. So, I think one question that you know there's some complexity here obviously and a lot of different inputs. As you imagine this tool, becoming more available hopefully later this year we'll see an online version that people can really test and play with. What level of sort of technical proficiency and knowledge will be necessary. Are we all going to need to get certified or what. I don't know that yeah. No, it's been a huge priority to make this really accessible and I mean it does get very technical but we're trying to balance default values and kind of you know user how to that make this simple to use with default and then if you happen to know more about your specific situation you can you can you know provide your own numbers and overwrite the system but you know the goal is that this is an early stage high level tool where you don't need to know a lot about building and you don't need to have a huge amount of technical proficiency. So that's been a battle we've actually we've we work well we're architects and we we've worked with a lot of architects on the development of the tool and they always want to make it a design tool they want to know. Well what happens if I use spray foam versus mineral ball and that's not what this tool is I think you know this is this is not a life cycle assessment tool it's an early stage estimator so it should be it should be pre accessible to people of with a range of technical proficiency. Yeah, and our assumptions and benchmarks will they're they're broad but it will sort of give you a description in the in the background when you want to say well what is that what's behind that number you can go and look it up and say what we mean by partial replacement of a building interiors this then you can sort of see does this match what we're thinking of doing so it's not hidden but it's not trying to be very specific either. So, Allison, you know, Boston Preservation Alliance as an advocate for for preservation. How do you think a tool like this could can make a difference in Boston. This tool again can help us make the best decisions for each site and you know I don't think we can promise that a tool like this is always going to lead to the result that we want. But at the end of the day, we are promoting reuse and continued use of existing buildings whether they're big age historic a little age historic, whether we have a tool that we can use for their preservation or not. But more often than not the best thing is to reuse what we have. And often when we can't convince our local government or you know the decision makers of our city about its historic integrity. We were seeing so much emphasis on climate action and climate goals that we can get some attention that way. So we plan to use this tool once it comes online to help at the very earliest stages of a development proposal, make the best decision for that site hopefully it can become regulation and required that that all development teams have to use this calculator or a similar tool to to make the best decisions for the the future of each individual building and site or campus, whatever it may be. And then we're also talking a lot about deconstruction and salvage so when we can't save a building or it's not the right solution. So we make sure that we're diverting reusable materials from a landfill and we're seeing different cities across the country really embrace that and build that into their policy. So we have some regulations that are fairly easy to get around for diversion to landfill but we really want to embrace that as a way to reuse materials. So how do we get the chicken in the egg, how do we create the market for those materials, and make sure that they're available. As architects, you know design new buildings and make sure those materials are catalogued and ready for reuse. So it's all part of a larger discussion and we welcome everybody to consider all of these as as larger policy decisions. And we're happy to talk more about anything that's happened in our conversation today. Yeah, awesome. Great. Well, we just got a couple minutes left so I want to just go back to the slides if we could for for to close out. And obviously this is is such exciting work more to come. Again, thank you to Lori and Larry and Aaron and the team. If you want to stay engaged here on the care tool specifically there at the bottom is a link to the ZNC collaborative. So please, Lori sign up to get updates on on the tool and the latest, certainly through the preservation priorities task force and our climate working group we're going to keep the website updated. And just to let you know this is now the first in what is going to be a series of PPTF webinars, including an upcoming webinar on climate justice, which is scheduled for early May so stay tuned for more on that. And stay tuned to the forum webinar series as well the address there. And then just one last slide. Chelsea. If you're interested specifically in PPTF we would welcome your participation and help. I'm a co chair, along with Lindsay Wallace from our main street, mainstream America. As a member we've got a great group of folks looking at all aspects of preservation and climate change we're going to have additional webinar series on on issues of adaptation as and planning as well. And then just if you're interested in getting involved in the PPTF. Feel free to reach out to myself or to Rebecca Harris at NPPN so again thanks to our panelists and all the who listened in we'll get back to you on your questions as best we can and thanks for your interest and, and more to come. Alright. Take care all. Thank you. Thank you all.