 Yeah, great. Good morning everyone and welcome to our public lectures of the tech talks, how which this semester focus on material cities and ethics. And please join me in welcoming Alison Mears and Sara Ruth, who will be presenting today their work on healthy materials. Alison Mears is an architect associate professor of architecture and director and co founder of healthy materials lab. She is co principal investigator of the healthy affordable materials project. Three year project funded by the JP JP be foundation recently refunded for an additional three years until 2021. The project is a coalition of four organizations who work together to detoxify the interior environments of affordable housing. Alison Mears focuses her research on design strategies that disrupt the building supply chain to incorporate human health as criteria for evaluating building products. Previously, she served as the Parsons Dean of the School of Design strategies and director of the BFA architectural design and interior design programs. She teaches architectural design studios at Parsons focused on building orbit and community issues, and she's currently a partner in the architectural practice patchy plus mirrors architects PC. Thank you, Alison for joining today and for Jen Sara Ruth. Let me introduce Jen Sara. Jen Sara is a designer artist and design director at healthy materials lab. She is founding director of the progressive MFA interior design program at Parsons School of Design. Charged with provoking change in the field she leads after taste, an annual symposium drawing from perspective from a wide spectrum of disciplines to bring new definition to the field of interiors. In her teaching, Jen Sara draws from practices at both their cutting edges and their ancestral roots to inform design approaches. Her ideas about designing interior environments focus on exploring and understanding human experience. As a designer she is committed to using materials and processes that maximize worker and user and planetary health. Today, Jen Sara leads salty labs, a collaborative design studio founded in sustainable thinking and testing experimental technologies. And she was the first lead designer for the Martha Stewart signature furniture collection, and her work is seen in hundreds of retail venues, thousands of homes exhibited in galleries and museums featured in publications internationally, and has received multiple Jen Sara is also a fellow at the McDowell Colony received a master's of facture from Cranbrook Academy of Arts and the BFA in industrial design from Rhode Island School of Design. Jen Sara and Alison's lecture today will be moderated by Catherine Murphy and adjunct faculty with us a GSAP who teaches the healthy building materials class. She also teaches at the new school. She's trained as an artist and designer. So Catherine's interior design practice is dedicated to making physical spaces healthier for everyone. Her response to the history of the place and the client, rather than adhering to a signature style. Her practice is rooted in craft making and the inherent potential of materials in their pursuit and healthy estates. So join me in welcoming Jen Sara and Alison. I'm delighted to have you with us today. Thank you Lola. It's great to be here. It's great to be with all of you. Thank you for the invitation to speak. So, I'm John Sara, and my partner Alison will soon be on the screen. We are co founders of healthy materials lab at Parsons. I think that maybe our screen view. I don't know if you can see us. Yeah. Okay. Great. So, so thanks very much for inviting us here today and next slide thanks Catherine. I think that we are co founders and we are co directors and collaboration is something that we emphasize in our work and our lab is a combination of full time design researchers, educators, communications experts and research assistants, and some recent design graduates and we come from a range of disciplines as do our advisors that you'll see there on the right next slide please. The materials lab in 2015, as we mentioned earlier, we are going today we're going to introduce or maybe reintroduce for some of you who are familiar with this work, the topic of material health and common building products and why this research our own research uses on a journey to look for alternative construction products. To be able to do interdisciplinary work, we and our partners healthy building network green science policy Institute and health product declaration collaborative are supported by generous grant from the JPB foundation. Next. Yeah, thank you. We have a number of projects running simultaneously in the lab from educational programming to publications and research. Next slide. In communications, the website and podcasts we share the share the work we create and educate and advocate for change, and we regularly publish our work. There are few design programs that include material health content in the US and elsewhere Columbia does now thanks to Catherine and the work of Lola. In the last three years we've created two online programs taught by 55 to 60 experts in the field, and a number of short courses to help designers change their practice. Next slide. We want to translate scientific and public health data to make it accessible and not an actionable by both architects and designers like ourselves, and to create new knowledge in the UVC project as something that we may talk about later. We're also exploring how germicidal UV light can be used to retrofit existing lights to work with ventilation to deactivate coven. We also look to change architects, architecture and design practice with resources to help that transition to health, healthier material specifications, what approach prototype new forms of building. Next slide. We search and collaborate with a broad range of experts exploring this relationship this complex relationship between human health and building materials. During culvert. It's been revealed that the compounded inequities and trauma of our current systems, many of these complicated systems that we are part of reveal that diverse communities that are now at compounded risk. Next slide please. As a city we in the buildings, all of us are the city and our actions and architects as architects and designers have impacts on everyone, but the most profound impacts we can have as designers on the most vulnerable. Next slide. We have a direct connection between the carbon emitted in the production of petrochemicals and the specification of petrochemically based building products of an obvious connection, reducing the use of these building products reduces carbon emissions. Next please. And we also make this connection between those products and our health so not only other products derived from petrochemicals bad for the environment, but that they are also harmful for us. And we also make these building materials shed these building materials that we use shed and release these chemicals into our built environments, which are then absorbed and become part of our biological systems. Next please. These indoor spaces where we spend so much time now more than ever are filled with invisible chemical hazards, making our indoor air three to five times more toxic than our polluted outdoor air. The chemicals that we use are not regulated. And this is a surprise for people are unfamiliar with this topic. Only 250 of these 85,000 chemicals currently in use attested, and only five of them have been partially restricted by law. Many of these chemicals are toxic and become part of our everybody's biology that means our bodies, they're embedded in our bodies. Next please. Materials and products break down, and the chemicals are released through off gassing as particles or as dust or as chemicals become unbound and released entire into our environment. Next please. Once these chemicals are loose in the interior space we breathe them in, we can eat them or they could be absorbed through our skin. Next slide please. Our partners that green science policy had come up with a system to understand the worst classes of chemicals, so that we can work to remove these six classes from common products. Next slide. We also understand that it's not not just about environmental exposure, but there are genetics in our body our biological systems are part of this same complex issue. So this problem of chemicals in our built environment how does it actually impact our health. We search this research study called the expert zone project has identified that genetics determines only 10% of human diseases with the environment accounting for the other 90%. Next please. The expert zone can be defined as a measure of all of our exposures all of these environmental exposures, chemical exposures of an individual in a lifetime, and how those exposures relate and trigger particular health conditions. Next please. What triggers these 90% these other 90% of diseases what makes us most vulnerable to diseases through exposure and these, I'm sure most of you are aware of these these remaining causes a trigger by the social determinants of health, the economic and social conditions that determine individual and group differences in health, where these social determinants are disruptive due to poverty, for example, diseases such as asthma obesity, and diabetes are triggered in those individuals. Next please. In the current crisis, the rates of covert are located tied to the same undeserved and marginalized communities that have been have been subjected to decade, decades of environmental and systemic racism. And so this is really critical making the link between poverty and rates of covered and rates of disease. Next slide please. Can you see this in these two research studies, whether we are more we are more vulnerable to the novel coronavirus if our defenses have been compromised by chronic illnesses like cancer diabetes or asthma. And experts have found these and other health problems are linked to exposure to toxic chemicals in our buildings. Again, it's in the BIPOC communities that have been hardest hit because of their social determinants of health. Next please. So it's critical that we build healthier and more resilient communities, dramatically reducing people's exposure to harmful chemicals is an issue of equity, both equity and public health, to protect those who have suffered because of these generations of institutionalized racism. Next please. Many of the products that are typically used in current construction these normal but now products that we take for granted, contain the chemicals that are linked to human disease. In our work we look to remove these chemicals and propose viable affordable and benign alternatives. So what if we look at a seemingly simple product like paint, you know we could have looked at plywood or any of those that Allison just mentioned. But if we look at paint, you know we know that it can create benign beautiful spaces. But paint can also be seriously harmful. Sorry, next slide please. Such as the lead paint that's still used in many homes across the country, like here in NYCHA housing these are photos of the lead paint next. Paints cover. Next slide please. The paints cover most of the surfaces and interiors. Many of the currently petrochemically based acrylic paints contain a wide range of toxic chemicals from VOCs to APEs to common ingredients that make up the paint. But while the Center for Disease Control might give a recommendation of five parts per million as being a guideline for lead exposure, there's actually no safe level of lead that really we're so susceptible to lead in anything. Next please. The first experience we have a paint is when we take off the lid, and we have that first paint smell which I'm sure you're all familiar with. That's filled with VOCs or volatile organic compounds. Next please. The second experience with our paint is when it's been dried and it starts to degrade as the dust into the interior spaces and then we can inhale it from the air that we're breathing. Next please. So where are our interiors and how did we get to this point. When we go to the next slide, you will see that there are four basic components to paint so we're just going to look more deeply into paint itself. There's binders, solvents, pigments, and additives. And that's those are the ingredients that conventional paint are made of. So let's let's go into those. Next slide please. So binders are the substance that hold together all of the different ingredients in the paint or coding to form a continuous film that adheres to surfaces and that's what we know as as paint. But synthetic binders are often called resins, and there are many types of resins that you see here in this list, including acrylic and vinyl which are basically plastics. Next please. The chemicals that that put together a binder can be a monomer. And here's where we go into chemistry and we'll have to rely on some of high school chemistry here. But a monomer is a link that's, that's not so tight. And so a molecule can can disengage from that coding and shed into this from the interior surface fall into the air the indoor air, and even drop to the floor, where people have a lot of our time, especially small people like children. And then they breathe in these these molecules. Next slide please. The next category and paint. Next substance category is solvents. So the purpose of solvents or the performance of solvents is that they're used to mix all the ingredients of paints and coatings to make the coding fluid. And that fluidity allows us to apply the paint to a wall, for instance. But many of the synthetic solvents that we that are used in paint are our volatile organic compounds or VOCs, which, which we know can affect us biologically. Next please. And in the mid 20th century, the, the VOC reduction began to be the driver in the coatings industry. Because there was recognition that the ozone layer was being destructed. And that was linked to these VOC emissions. So VOCs have begun to be regulated and you'll, you'll notice that on, you know, low VOC or no VOC paints. Next slide please. Another category, the third category that we talked about is pigments. So pigments is what give paint color. And maybe that's pretty obvious. Pigments provide color and opacity actually to any kind of coding but also to paints. But, you know, synthetic pigments have replaced many of the naturally occurring pigments that have been used historically and some that synthetic pigments were were used to to develop coverage and colors that were difficult to achieve originally with natural pigments. One example is for instance titanium dioxide was a white pigment that replaced white lead carbonate. So it used to be that white paint was led. And then it switched to titanium dioxide because not because people were trying to get rid of lead unfortunately but because instead titanium dioxide actually is a much more opaque coating. It made that white more opaque. But of course, titanium dioxide isn't such a great substance either it's also known as a carcinogen. But so many of the other pigments also contain VOCs which can be harmful to human health, triggering things like asthma and sometimes cancer. Next slide please. And additives are the last of the four categories of the ingredients in paint. Additives are the materials that are included in smaller quantities to modify some property of this coding so one example of a of an additive is called an APP or alka fennel xylates. And these are used to emulsify all of the the ingredients in paint and make it nice and smooth. But recently this group of chemicals has been linked with endocrine disruption in people's bodies, causing problems, such as obesity, diabetes, male reproductive disorders, or even altered brain development. And so this is kind of alarming news about paint. Next slide please. So these are the general ingredients in conventional paint, which we can we can look at again here. And this is what we know of as paint and you know, one of the, one of the misnomers is we call it latex paint but actually, it's not latex at all. It's actually acrylic or vinyl or some kind of plastic, it's synthetic plastic that comes from a petrochemical base. So what we did, we just said, well, let's look historically, let's see the way that paint used to be made. And so we can see that historically and in these ancient cave paintings in France, paint was made of natural materials they were made of stone. And of facts, and the binders were actually facts, where the pigments were ground up stone. Next slide please. Later, it was found that in the Egyptians and the Greeks and the Romans that their binders were actually from animal bones, or from beeswax or from eggs. And then they used water as the solvent. And the pigments were again these three basic primary colors which were ground up minerals. And so that was the the ingredients in ancient paint. Next slide please. In Italy, there was another kind of paint where the binder was actually lime putty, made from limestone. And again those three basic pigments were used to make color and those pigments were minerals, and water remained as the solvent. Next slide please. So we're now on this continent in early colonial America, the paints that the paints were used binders that could easily be found in the landscape so the chickens provided the egg yolks and plants and nuts provided the oils for the binder itself. Next slide please. So you know if we look just historically, prior to say the 1940s or 50s, we can see that there were three basic categories of binders of paints. There was oil, oil based paints, water based paints, and lime or milk based components and the milk based is actually lime and milk are mixed but the milk it's the casein which is a casein is a protein that's found in milk and that was used as the binder. Next slide please. But there have been dramatic changes in the composition of paint, which began in the industrial revolution, when the synthetic polymer binders were introduced. And these synthetic pigments were also introduced. And then synthetic solvents were developed to mix all these synthetic ingredients together so that they would feel like one cohesive thing. And then there were additives. And the additives were something, all kinds of additives. Another additive was a chemical preservative, so that it was invented so you could put a can of paint on a shelf in a retail store and it would last for a very long time. And you could imagine what would happen if you put eggs on a shelf or milk on a shelf for a very long time so these chemical preservatives were added to the paint. Next slide please. But the legacy of these chemicals used in paint production was never addressed. And frontline communities that surround the industries that make these chemicals saw rising levels of cancer and asthma rates. Next slide please. This is where our work comes in, where we look at the comparison, we're comparing. So we look on the left, we see a list of ingredients in typical low or no VOC paint, house paint, which is, you know, it's promoted as being so much better. But we see these ingredients and many that we can't pronounce. And then the colors, if you can see on that slide the colors indicate the substances used in paint that actually are linked to human health effects from those ingredients. And then if you look on the right in historic lime wash, which is now actually this is a paint that's being produced now that's a lime wash being produced now, and it has three ingredients, plus one other ingredient to keep the binder a little bit more flexible. But you know it's very similar to the way we think about packaged food. For instance, if you see a lot of ingredients and ones that you can't pronounce, it's probably not good for you. But there so there are alternatives here. Next slide please. Currently, these are, you know, some current natural binders that are used in paint. We talked about them there. There's a casein paints the milk protein or natural latex actually because it's natural latex comes from trees. Unlike the acrylic paints that we know now oils that comes from plants and trees limestone makes lime as was just used as a binder and linseed oil which comes from the flak flaks plant. Next slide please. And now there's the natural pigments next have been now available and there's a much broader variety as humans have developed we have many more colors that are actually come from minerals. And so there are, there are alternatives and I think that's what we're coming to. Next slide please. You know, we know that water can be a great solvent for many things. And if we this deep dive into paint just reinforces the fact that transforming one product category can actually make a big difference. But it requires a radical upheaval of an industry and changes to specifications and to thinking material thinking and practice. Next slide please. We can, we can use healthier paint alternatives we can uncover those alternatives and we can start to use them and they have, you know, in many cases better performance characteristics of petrochemically derived paints. But how do we make systemic transformational change in architecture design and construction to completely change the way we build a wall for example. Next slide please. The typical wall section in the US has seven or more ingredients, many of which are made of the same petrochemicals we discussed earlier. Those that are most harmful to human health. Next slide please. Even gypsum wallboard one of the most ubiquitous building materials in is seldom 100% gypsum. It often contains fly ash and carries traces of heavy materials like mercury. I imagine that gypsum is such a benign product but then it's the editors that are problematic. Next slide please. Faced with all of the problems associated with chemicals in common building products we look for alternatives. And through this we've discovered hemp crete or hemp lime. Next slide please. In hemp lime, the typical wall session can be simplified to three layers of breathable safe materials, all of them derived from hemp lime or water in different proportions. Next slide please. The benefits of building with hemp and lime are impressive, and it's a healthier alternative to typical building materials. The material also brings together a lot of goals in one place with the potential to make systemic change in a range of industries. So if we look at the list of characteristics of hemp and lime, it's recyclable and biodegradable. It regulates indoor humidity and climate. It's a natural carbon sink. It creates an energy efficient insulation. It's naturally fire resistant without any added flame retardants. And it lasts for a very, very long time. Next slide please. So we tend to look at these systems. Systems are kind of characteristic of the lab and we're really looking to see how we could perhaps propose a new regenerative construction system that could be derived from materials that have beneficial properties. We want to understand how this system might be created, what the roadblocks might be to adopt adoption, and how we might act to create new connections. If we think about the social determinants of health, for example, what makes a healthier life? It's more than just the materials that make up your home, looking at the whole life cycle of hemp and lime and the systems of production that support this kind of building. We see that people and whole communities can benefit from this system. Next slide please. We start with the transformation of architectural practices where industrial hemp can regenerate the soil. With a developed hemp lime building industry that creates a market for the product that is grown in the fields, people can remain employed and make a living on the land. Next slide please. A new industry. Sorry. Next slide please. A new industry can support job creation in facilities which process fiber hemp, for example. Next slide please. And more potential jobs with facilities that produce hemp lime building products. Next slide please. This is the first development in the masonry trades and there will be a revival of vocational training for masons and plasterers. So there's a whole labor component of this system that is critically important when new jobs are created within the system. Next slide please. The transformation of construction and housing in a small city in western Pennsylvania, Newcastle, a commercial center of a fertile agricultural region. And like many small cities in that region, it's heyday was in the early part of the 20th century, when industry was booming. Now it's home to many old houses in need of rehabilitation and ready for new industry. There's a potential to renovate existing abandoned framed houses. Renovation has a relatively low carbon footprint compared to new construction. And a small towns and cities in the northeast, where much of the existing housing stock is built at the turn of the century, excuse me, from wooden from wood using balloon frame construction. Hemp lime can be used not only as a healthier insulation material, but also to help add fire resistance to these buildings. The whole system of hemp and lime building materials has the potential to enhance people's lives through job creation, nourishing the environment, creating better healthier homes for all people. So this is our vision. Next slide please. And also the vision of a small local powerful affordable housing provider in Newcastle Don services. They see hemp lime building and the whole system which fuels them as an opportunity for Newcastle and for the development of affordable housing at large. Next slide please. So we're architects and designers and we believe that our work is to design healthier spaces for everyone. We're also professors teaching the next generation of architects and designers, and we believe that it's critical that all of us address the largest systemic issues of our time through design practice. Last, next slide please. Next slide Catherine, if you can. Thank you. So last winter we teamed up with faculty and students from Parsons architecture programs and Pusari Datna at Don services in Newcastle Pennsylvania. Next slide. We began with a workshop in January 2020 when we could be together pre COVID to introduce the students to the material qualities of hemp lime in a full day hemp lime workshop. This was the first step for students who would explore this novel building material as a focus for their design studio projects for the rest of the spring semester. Next slide please. This was a rare chance for architecture students who seldom have the opportunity to experiment with materials at full scale or explore buildings, building with natural materials. Next slide please. In the workshop, the students were able to understand the physical qualities of hemp lime casting processes and block making this ignited ideas for students whose next step was to propose designs for affordable housing in Newcastle. Next slide please. The master of architecture students continued their design process with fundamental demographic research of Newcastle to understand the basics of cost of living, housing and the median incomes in this area and this, this small city has many of the same characteristics of a lot of the post industrial cities of the rust belt with very low incomes, abandonment, low employment, low cost of housing. Next slide please. In terms of affordability students explored construction costs to compare savings for renovation versus new construction, as well as to find savings which could be allocated for hemp lime construction materials and fabrication. There's a minimum savings of 43% of the total construction costs for renovation versus new versus new construction, a savings in dollars as well as a carbon emissions. This savings could be dedicated to the implementation of hemp lime materials and construction which still comes at a premium. Next slide. With the goal of scaling hemp lime construction into a mainstream method for renovation students made this critical comparison between construction timelines for cost in place at hemp lime versus precast hemp lime materials. It's proven that one month could be saved if precast materials are used and this is critical in the construction process, obviously to be able to meet traditional construction practices. Next slide please. Students were asked to design homes on lots and one city block that addressed the future of the American home and that could accommodate multi generational living be built affordably be fully accessible. Detailed construction drawings using hemp lime materials and techniques. Next slide please. At the end of the semester there was some enticing proposals and some extraordinary learning for both the students and faculty who were wrestling with drawing details for hemp lime construction. This proposal called house with two porches proposed by Samuel Wilson is a simple form that can fit into a variety of residential plots with a simple interior layout to address the needs of a variety of family types. Next please. Each student's project resulted in unique insights into designing with hemp lime. This new material also challenged and inspired the faculty who were learning alongside the students. Yeah, so you know it's not just the adoption of a new building material that's required to make change as Allison was saying, we actually looks, we are our work is really about making systemic change. And that's the, the goal of Don services as well so we're looking at supporting agriculture, creating new industry building workforce, creating new work for the nation retrades which are kind of dying at the moment in the United States, and reducing carbon emissions in total. So, you know that's, that's our major interest here. Next slide please. At Don services, they are have the same goal, and it's so it's pretty amazing to work with them. They've decided to work on two areas to make this change. One is the cultivation of industrial hemp. Next slide. And so at Don services they work with local farmers and began growing hemp in 2019 just when it began to be legal in this country and they be they planted hemp in Western Pennsylvania this is Mike, holding their very first and only bail from four acres. So, as many of you might guess, beginning a new venture is tough and it requires a lot of trial and error. Next slide please. But just this past summer in 2020, being outside was pretty great in 2020. It was a better year for the crop, and they don services received a grant which supported education for hemp farming assisting farmers to plant hemp in four counties. The participants were chosen from a list of 59 interested farmers and to test the planting methods and they planted 14 acres, experimented with two seed varieties and tested planting methods with grain drills and with broadcasting. Next slide please. The harvest yield was about 77 small square bales so they're getting better and and 16 large round bales of hemp. Next slide please. This is collaborated with hemp wood which is a company that makes wood out of like a planks really out of hemp. And so they're making this some of their harvest into flooring which will be ready to install in the new Pennsylvania hemp home, which is also pretty exciting. We're going to use their crop as the product materials. Next slide please. This is another pathway that we're exploring which is how do we accelerate the production of local lime as well into so that we can mix hemp and lime. So that we can make viable construction materials. Next slide please. Here's when we turn to our colleague Cameron McIntosh also from Pennsylvania, and another partner on the Pennsylvania hemp home project with Don services. Cameron on the on the right you'll see Cameron was also a guest this summer on our podcast talking about his construction practices using hemp line. Next slide please. A little bit of an insight into Cameron's work he's developing techniques for renovation with hemp line materials by combining several different techniques here on the left you'll see he's using the easy spray technology with with the easy bait binder mix. We're also distributed in the US by a company called hemp a texture but so we're still importing a lot of the best materials for hemp line from Europe, specifically from France. And that we're looking to change that and really make it locally but at the moment the best quality materials are from France. So this kind of spray technology is a great option for renovations and it will be the technique that we use in Newcastle, the spray system reduces labor and time by actually by 60%. So it's pretty, it's really efficient. Next slide please. So in order to demonstrate the material interactions and cross sections of this upcoming renovation. Cameron and his team create full scale mock ups to just show the code enforcement officials. What a new wall section might look like and how it would perform with hemp line, because you know code officials are not used to this material. And we, we have to act as advocates for the material itself. And as many of you might know full scale mock ups are really incredibly valuable. Next slide please. How close are we to bringing the whole system to fruition in the United States. And this is why and, and what we're exploring with dawn services in Newcastle to explore what the roadblocks might be and to prove that we can do this. Next slide please. Thankfully, Don was was awarded with us $75,000 grant from the Department of Agriculture in Pennsylvania to retrofit a hemp home, which is what we're involved in, and also to conduct research and testing, which will support that the acceptance of hemp line to into the construction code. And we will also be testing for indoor air quality, indoor environmental quality for our own research and promotion of this material. Next slide please. So like in many post industrial cities in the United States there's many vacant balloon framed housing stock, like Allison showed earlier done services now has purchased this small modest but we kind of love it. This house in the lower east side of Newcastle, and this will be the project PA hemp home. Next slide please. And the idea is to prototype the hemp line retrofit and create a demonstration that this can actually be done so that similar communities across the nation could do the same thing. And so we'll do this and then it will be open for a while before the tenant moves in to actually be like kind of an open house and an experiential demonstration house. Next slide please. So you know this method, as we're saying is very new in the United States and it's been tackled by contractors like we see in with Cameron, but it's new to architects. So we've been working on the plans here we've also been working with LTL architects on methods of drawing the hemp line in section. And so what does this actually look like in wall section. And here's some of their sketches. Next slide please. So if you haven't already guessed, we are really encouraged and excited by the potential for Newcastle to prototype this hemp line affordable housing. We're excited for the city of Newcastle and for the potential for this home to demonstrate healthier way forward for cities nationwide. And we think this very well me a prescription for a healthier future for renovating housing to be healthier affordable and made from locally sourced materials which invigorate the whole system of economies and workforce. Yeah, so this is a project that we're, we're, we're interested in it's on the move actually that house is now under deconstruction and will be accepting a template new insulation of hemp line in early April, which is, is we're very hopeful for spring. So we'll, we'll talk next slide we'll just talk a little bit about some other projects. Yeah, thank you, John sorry. So, one of key activities in the lab is really to disseminate information about the work that we're doing to advocate for change and to encourage all architects and designers to come on board with us to start at least asking that question of kind of what's inside the materials that you're specifying and start to work with industry to demand change. There was an publication an upcoming publication that was an outcome of symposium that we have held just over a year ago. And we hope will be a you know contribution to knowledge in this space to share this with with other architects. This is an event where I think there were 25 experts from a range of different fields from toxicologist to architects to innovators material innovators and carbon thinkers came together to start to think about, you know how we could transform and to find this this area of material health. We know that architects and designers love images as we do and love to know what's going on and so we use our Instagram platform with Facebook as a way of disseminating a kind of current current projects within the lab ideas that we're exploring other heroes in the space that we like to elevate for the work that they're doing in the same space. And we'll next slide please. And we use our website to as a primary platform, for disseminating the research that we're doing and the new knowledge that we're creating in this case is some collections of healthier building products that have been evaluated by us and when they have a yellow dot they've been used in affordable housing so it's a way for folks in affordable housing to be able to easily access healthier materials. Next slide please. And as John Sarah mentioned we launched our first podcast season last year, finished the beginning of this year it went on for longer than we thought it would because we were so excited about him, obviously. But our second season upcoming in the summer is focused on, you would guess it, what would you guess, plastics. So we were funded by our grant from the NEH to tell the story the cultural history of plastics in the US, and to think about kind of new futures that, you know, have less plastics in them. And then if you sign up for a mailing list next slide, you can hear about the events that we host through the lab this was an event that we hosted last Thursday with our friends, Martha Lewis and Pelle Munch Peterson, looking at this relationship between carbon and chemicals. Last slide. And you can find all of our resources on our website. Thanks very much for listening to us. Thank you so much for joining us and John Sarah, that was a really wonderful presentation. It's full of hope, which is really encouraging. But at the beginning we were talking as we were getting set up about the challenges with finding all of these materials and the detective work that needs to happen. But I have to say this presentation has been has given us a lot of good leads as we move forward and particularly for my students as we move into that to the rest of the semester. So thank you both. I just want to, I will want to ask a couple of questions and I know that people joining us and welcome to all of you for a great audience today. I do have questions to ask. I first wanted to just quickly thank Lola for organizing these events and it's her vision really for building science and technology. She's brought such diversity to the tech sequence. And her beliefs align really closely with our own teaching now so there should be a purpose and the work, and the people are really central to the work that we're both doing. So I think just to get started, even though you ended on such a high note, my first sort of question is, in the midst of so many crises, how do we, and when the inclination is to want to act that there isn't enough time to think that we have to act. Where do we start to ensure that our space is healthier? And what is that road ahead like from this moment in time? Maybe I'll just start. It's a very good question and I think that what we've found in our work is that these kinds of changes happen with a personal choice. And so that personal choice begins with our own homes, you know, our own environments. And when you start to become conscious of everything that you're bringing into your life, into your own environment, until your own 90% of that exposome that you're experiencing, then you become conscious of the things you bring into your space. You make them and then incrementally you can make those choices healthier. We can consume less, first of all, but then, you know, as when we do need to bring new things we can bring in healthier ones like just simply have healthier cleaning products for instance because cleaning products really can pollute our indoor air and we're spending a whole lot of time inside lately. So understanding that, you know, healthier cleaning products don't come with those nasty chemicals in them. Those nasty harmful chemicals is really important. Another simple thing we can do right now is take off your shoes when you come inside because then you won't be bringing in things from the outside that might be toxic or, you know, potentially harmful for yourself, or for your families indoors. And of course, opening windows and letting fresh air in because now we understand that the outside air is cleaner than usually than our indoor air and so ventilating is really important. I wonder if Allison you have anything to add to that. Yeah, we work with Mount Sinai, their environmental health group there and they came up with this kind of nine first steps. We have them on our website, we can share them with you if you're interested, but it included those simple steps like taking off your shoes, opening the window, really thinking carefully about cleaning products and the HEPA filter in your vacuum cleaner. Those are things we could all do. If you're painting, look for an alternative paint, look for a lime based or other non acrylic paint, because paint covers so many surfaces in the space that you're in that it's a really simple way to transform your interior environment. We're also thinking again. I think to the future, a project that we're working on with the MFA lighting program at Parsons is how we can retrofit our environments to combat future viruses what what can we do in our own environments to retrofit and so one thing we're working on right now is the use of germicidal UV or UVC light that can be installed in existing light fixtures and works with ventilation within existing space and that deactivates kills the COVID virus and so that's one of the projects that we are engaged in right now and all the way through to the summer I think and for us the potential within affordable housing is profound because we think we anticipate and we hope that the retrofitting of existing light fixtures could be something that is a very low cost change to an existing fixture that will have this potential to be to make a radical change in affordable housing. Speaking there Alison of affordable housing because that's really central to the work that you're doing at the lab on the broader scale then, you know, to transform those that market with healthier materials, and it seems like an honest task is it, you know, is it doable what are those steps where the designers and architects here today, you know, where would their first steps be. Yeah, yeah, we, and Catherine knows this we've conducted five case studies when we launched the lab to understand the current state of affordable housing in the country again to do that kind of systems diagram that we're so interested in, and there are huge roadblocks and affordable housing to making change and one is the financial structure, how we fund affordable housing it's incredibly complex. And the construction costs, you know with the soft costs of the regulations and the lawyers that are involved in the finance mechanisms. It ends up per square foot being more expensive to design and build affordable housing the market rate housing. It seems absurd right so there's something wrong with that system, where you're confronted with the roadblocks of money in a very kind of odd way. That's the thing we have to overcome structural racism, affordable housing nature housing that we know in New York City is built on the worst land and though in the areas that are degraded environmentally next to highways on, you know, wetlands that have all kinds of problems that are underserved that are under maintained. We need to, we advocate for healthier housing for everyone that this is a, this is a basic right of all of us living in this country and everywhere so you know confronting structural racism in our own work understanding that affordable housing should look like housing should be like housing it shouldn't look like anything else isn't any different. I think I kind of mindset, but will help us overcome some of the kind of intrinsic and and really difficult challenges currently in that market. And I would just add to that that you know simple changes in material choice can do a whole lot. Like, you know, because it's affordable housing, most, most people involved making decisions, want to shave costs at every turn. So they'll, so they'll shave, you know, a few dollars off a square foot by choosing a less expensive tile in a floor tile for instance, using vinyl, for instance, instead of something a little bit more healthier. And what they're not looking at is the overall cost. So if we look at choosing a vinyl tile versus, say, a linoleum tile which is linoleum lino is is is from the the flax plant is from lino is from linseed and that's a flax plant and that tile is maybe $4 more square foot. But over the lifetime of that product, it actually comes out to be about the same because it doesn't require the same kind of cleaning. It doesn't require the same kind of resurfacing. Overall, it doesn't require the same kind of health bills and emergency room visits to the overall community, because it's not going to cause asthma to children or to adults and so, you know, the way that we think about finance really has to be different, we have to think about the long term. The long term cost, which is about health care costs. It's also about cleaning costs. It's about maintenance costs. It's about people. And so, you know, there's some very basic changes that could happen very easily, which we don't need regulation for we just need to be smarter about our own choices, you know, regulation takes a long time, and we rely on other people to make those choices. But we actually have a lot of agency in our own choice. That's the call to action we need to hear. I'm going to check with to see who'd like to ask a question. There's one question in the chat from Sam. How easily accessible is hemp line. How does cost compared to typical gypsum wall, etc. benefits and disadvantages and I might add that it, we might not want to compare it to gypsum wall but to hold like insulative infill. Yeah, so how you're answering the question. How easily accessible is hemp line. Well, you are developing the project in Western Pennsylvania. So it's, it's really interesting to hear from you. The accessibility of these materials elsewhere. So is it accessible now in all states in the US and what is the policy situation with material. We talked about it a little bit right and and you know I think john Sarah mentioned that that most of the hemp herd is coming from France at the moment and that's because it's a very new industry in the US it's only since the 2018 farm bill that industrial hemp can be grown in this country so there's a lot of kind of catch up to do in terms of the agricultural piece of it the knowledge in terms of farming practices and then and the processing of the stock to to get the herd, because the herd has very particular property properties, it has to be processed in a way that retains those properties, so that when you mix it with the line, which also has very particular properties, the combined, you know, the combined mix with water enables you to achieve the insulatory qualities of lame retardant properties, the ability to modify and absorb and release humidity in the wall. So that's why people are relying on imported ingredients at the moment, and they're readily available. So they're pretty easy to import right. But I would say that there are becoming more. There are line mixes now that are available from Pennsylvania and from Idaho. There are folks who are really, I mean there's a lot of people actually there's a lot of people who are really dedicated to making them available in the United States in all different regions. And so, there's an organization called the hemp, the US hemp building Association, which has regional groups, and they're each region is really promoting, you know, more solutions to sources that are in their own region and so you know the end goal is to have it all be locally available wherever you are. So it is available now, and there are people who are distributing in the US which is really great that wasn't true a few years ago so so that's pretty great it's, it's pretty, it's pretty accessible. In terms of the question about the wall, it cannot lowest started to answer that question because we, you know and I think Allison described this to what when she showed that that that layered the look of the you know the wall section, and that there are seven or more layers in a wall. This hemp lime substitutes those seven layers in actually just three layers, it can be hemp lime in the middle as an insulation material plaster on the interior and kind of a rougher kind of stucco on the exterior, and that creates the wall section. The more insulation it is the more insulatory it is. And so we have to think about walls differently. You know, you know it's kind of interesting too because, you know that historical way of building walls was more similar to a hemp lime wall than it is to the seven layers that we've come across. And then if we think about this whole discussion that's happening now of embodied carbon versus operational carbon. What it does is that the whole industry has pointed to operational carbon. And so the whole idea is like, let's keep the heat in let's keep the cool in. Let's not let there be too much exchange between outside and inside so that we can be more energy efficient. But actually, the calculations say that the energy used to just make the building materials, not even talking about the health of the building materials but just the energy used to make those building materials is far, far more harmful and far more, you know contributes far more to climate change than operational energy at all. In fact, I think. Yeah, Stevens making some good points about, you know that the hemp criticism also marvelous way to reduce embodied carbon. Yeah, exactly through its through its life except in the production of the line. So, Well, that's not true, not true, totally. Because Sarah is the lime expert here. Well, you know and and there are new ways that the lime is being produced but the thing is, yes, limestone I think I'm going to defend lime, but you know limestone lime is produced by heating up limestone and limestone is 8% of the Earth's crust like there's a lot of limestone on our planet. If you heat up a piece of limestone it has to get heated up to like 1200 degrees, something very high. That's a lot of energy, yes, but lime reabsorbs the carbon it's admitted, even like maybe twice as much as is admitted over the course of its curing process, and it continues to absorb carbon over time. So that's where that's where I defended yes, there's an initial emission of of carbon and energy taken to do that but then it does reabsorb itself, and then together with hemp which is a carbon sequester, all together as a plant, it sequesters carbon like trees. And then in use as part of that mix of hemp and lime that wall, wall section continues to absorb carbon dioxide over the life of the wall, which is kind of phenomenal. I think there's a lot of discussion about local government and I think the Pennsylvania project is really interesting because you see the power of state governments to support the kind of activities that are happening in this project in Newcastle so they're hosting grants for agriculture so that some of this testing this new knowledge can be created through experimentation with seeds and sowing protocols and then harvesting industrial hemp is something of a kind of complicated plant to grow, and then they're also giving grants for construction and testing of new structures so that seems like a very powerful way to support and change and develop this kind of new hemp lime economy. We have a question to from Sammy, and then Henry had his hand up so he might ask you in person but I'll pass on Sammy's one first. And he wanted to thank you first for all the work that you're doing. And his biggest difficulty is in finding the time to find the healthier materials and to get his contract on board. Yeah. Yeah, it is, it is time consuming. It's totally time consuming to find healthier materials and you know that's that was the impetus for us to just list some of those that are proven to be healthier on our website. I did these materials collections. And I see that Leila is here too she's a senior researcher who really does an excellent job of curating those materials that exist on that website to make sure that they definitely are healthier. They're just examples really, you know we've gone through the process it is time consuming. This is a list of examples from each of these categories of materials that that are healthier. There are two and there are some other ways that you can evaluate. And you know, there's just some basic thumbnail ways that you can, you can find a healthier material and one is, what are its ingredients. They just ask like what's it made of, and that's becoming easier to find out there are something there's something called the health product declaration, or a declare label, and both of these labels list the ingredients of a building material. So, and the pretty quick to find you could find that information in about five minutes. Once you look at those ingredients though, you have to make the evaluation is that's okay or is it's not okay. You know it's like it's like that common sense if you can't pronounce it and if it has like lots of polymers in it, you might consider a different material. Yeah. Yeah, so the interesting thing about our materials collections to is is a great resource, like if you don't have the time to do that fundamental research and it takes hours and hours and hours to evaluate one product so you could use our materials collections in that way as a resource for you and the benefit of using our materials collections not to sell them, you know, whatever but it's that all of the materials that we evaluate have been installed have been specified and installed, and specified and installed sometimes in affordable housing and that for us is critically we're not really interested in being on the on the bleeding edge of of product use without having any kind of experience using a product. So, I mean that's the contractor question that you know that's the challenge for contractors is when you say we have this great new product this lime paint, and he says well, how do you install it how do I paint with it is it going to perform in the way that my acrylic paint works. And no it's not going to be quite the same way it is installing, and it's going to be different from the acrylic but it's going to hold up in this space and in a different kind of way that is, you know, that as a performing as a performance issue is absolutely comparable in terms of performance but superior in terms of kind of health outcomes. Here's a question in the chat here about hemp lime is an insulation, hemp lime is an insulation material. That's what it that's its performance quality. It's, it's insulation, it's not structural. It's insulation, and it's a breathable insulation. So it allows. And because of the lime in a big way, it, it actually absorbs. It absorbs air from both the inside and the outside air, and it's and it regulates in between and that's how it acts as an insulation material so it's, and it absorbs toxics from the, from the air so like an interior it actually absorbs it absorbs toxics, it absorbs humidity when it's too humid releases humidity when it's too dry inside, and there's, and there's an air exchange. So, some people, you know that's why we use the word hemp lime, instead of hemp crete, because we don't want to confuse people to think it's like concrete it is not like concrete, it is not structural. The name was given I think because when it's wet, the consistency when it's wet is a little bit like concrete, although it's very much, it's very lightweight, whereas concrete's obviously very heavy, but you can use a concrete mixer, like in its wet state it feels more like you can deal with it like concrete but it's nothing like it doesn't perform anything like concrete, nothing actually opposite. Oh, sorry. Sorry, I just wanted to follow up because I asked that question but I was wondering, I guess I was wondering because in the wall section that we saw in the presentation I did see insulation and so that's kind of why I asked I saw insulation in addition to the hemp lime so. So I think you saw the hemp lime blocks in the in the sketch detail. Yeah I thought I saw an insulation hatch. I think it was just the hemp line blocks, you know what we're experimenting with is precast hemp lime materials with wet kind of spray applied or form applied, and we're experimenting with combining those two. The issue is dealing with hemp lime is that it takes a long time to dry a very long time. It takes all that time to absorb the carbon back into itself from from the air and so, and that's what cures it. So that process can take six or eight weeks, depending on the thermal their climate conditions of where you are. So, one of the ways to make that much quicker is to precast materials precast the block or precast the panel. Let it dry in the factory, bring it on site, and then it's our it's like a building material it's ready to go. So, but, you know getting that full thickness that you need is much easier to do if you're spraying so we thought it would be good to combine that, you know, if you put a precast material, say on the inside and you spray from the outside. You can get that wall thickness, but you can also continue construction on the interior without waiting for it to dry. So maybe that's what you were seeing that. But it's a super important question. Yeah, because that is why, you know, many people are looking to hemp lime as as an alternative to traditional installation. And I see Stephen also in there. So one of the testing, one of the tests that's happening right now is to say, you know, how deep should that wall be what's the our value I can expect from this from this 12 inch wall this 10 inch wall, and then actually being able to demonstrate that you're getting that value for the wall. So, you know, this is early days in some ways in the US for exactly determining it's not like slapping up a piece of styrofoam or five glass insulation, where there is a predictive range of in solitary value there. This is slightly more exploratory at this moment in time and so those standards have to be established so that you can say well a 10 inch wall is going to give you an our value of blood, if it's detailed in this way, or if it's 12 inch wall in this. So, you know, again, this is work that will happen definitely on the PA house that we're working on that's the kind of testing will do. And then we'll have evidence of, you know, hemp lime used in a renovation project, which will be great I think. Okay, and I'll just hand me had his hand up there Henry did you want to ask your question. Thank you very much. Awesome to size really interesting. Um, medical question I thought was interesting the kind of case study with paints returning to kind of water and natural pigments obviously the case study with hemp line. I apologize to Catherine of my peers some was banging on with the same kind of question but with Newcastle this case study where there is a high degree of resiliency by having a regional economy that's then feeding new healthy material. You as directors of the lab, this question of scalability right because you know some of these new toxic chemicals were added to materials in terms of performance performance becomes to a certain extent, an economic measures do you have corporate consolidation so I'm referring the camp lime to Dow chemical and their insulating foam panels. It's obviously very important to have these kind of pilot projects we think about a market like New York, where there's huge volumes of construction. And the question is how do you break down the supply chains to allow a better material to become as ubiquitous as these hugely ossified and very rigid supply chains that exist because of mostly bad act of materials. So specifically I guess my question is as directors of the lab I know you're doing a lot already but how do you envision the process. After these kind of pilot projects for diverse materials to scale up because something that we talk about a lot in the class what are the barriers and stresses on getting healthy materials out there. And I'm wondering how much work you're doing to kind of think about those timelines and road maps to kind of work inside of those processes. And that's where we start I mean we don't want to be. I make this joke all the time we don't want to be the hippie architects who are interested, you know with the Birkenstocks and the mud rick houses and all of that we really are interested in transformation. And the only way we can do that is if we propose scalable solutions so that is something you know that led us to this idea of constructing hemp line blocks that are similar in size to a concrete block that. Can I talk about this. Well anyway. Yes, innovating in innovating in production using existing industries that are underutilized. So that kind of product development piece of this is incredibly important because if you can factory produce something, you can produce a scale and you can reduce the price and you can make it available. All over the country. The other thing that we're interested in is supply chains that we work regionally agricultural is a regional activity. And so for us it's really thinking about creating these regional centers of production, not only of the growing the industrial hemp, but processing the lime and then putting those two materials together to make a range of products, and then serving your region rather than it is a kind of national distribution system, but that's a political choice, you know, as for us as much as as a scalable kind of option for making change. Yeah, I would just add that you know we, there's a couple other ingredients into making scale which is optimism, believing that it can happen. You know having this kind of vision and then gathering people to just come on board and know I think that the hemp lime or you know they, a lot of people called the hemp Creek kind of revolution has really is really escalating just even in the last you know became legal to farm hemp in December of 2018. And now there are regions, there are people organized. There's a lot of motion towards making this happen and if you think of who started Dow chemical in the first place. I actually don't know who who the person is but you know it starts with this idea that it can happen. And we really believe it can happen. We really believe that invigorating people to work in fields and and soil and plants versus working in chemical factories, like the one that we've shown some photographs of is a culturally a much better future for our culture and so, you know, we have to demonstrate that it can happen. And we know that we have the technology that that will make it happen. We also actually we didn't show slides but we visited places in Europe where hemp has been farmed for many, many years, many more years and we saw these precast products being produced with robots actually in Europe in different parts of Europe and by hand in different technologies. Industrial, you know, the kind of industrial processes that have been developed over like Allison saying that have been developed over the last 100 years that are being retrofitted to accept hemp lime as a material, or as brand new processes that require robotic arms to make these hemp, hemp lime, you know, building products so you know the scale has been proven in our eyes. It's just hasn't yet been adopted in the United States, but there's a lot of knowledge transfer to happen from other parts of the world. You know, like in China, for instance, they've been planting and and harvesting hemp for hundreds of years, and they never had us. It never became illegal and, you know, equated with marijuana and stopped like it did in this country and so they had this kind of depth of knowledge about how to actually work with the plant. So, yes, we believe it and we have to remain optimistic that it can happen. For us also scalability equates with affordability and that's the bottom line for us we're also not interested in creating solutions that only a few people can afford that that's not mandate that's not what we're interested in doing. We're not interested in creating a productive, you know, valuable economies, but in a different kind of way so that there are affordable products that could be used in in everyone's house, not just in the houses that people couldn't afford it. Yeah, I have a question related to that. Sorry, Catherine. No, no, go ahead. First of course, thank you for this super inspiring presentation. And thank you for doing this work of converging policy with, you know, hands on and really theoretical studies also and with chemistry and biology and a human health and affordability. Taking all of this together and of course the focus on the retrofit and weatherization of existing buildings. This is seminal. This is so important. So thank you. So a question about this. The point that you just made Alison that I completely agree with that it's really to make a viable sustainable healthy building solution. The industry should be in place, or there should be an economic financial incentive. And of course the building policy should be also there for this. So my question relates to of course to clay, which is one of my main materials used in the area of, you know, earth and bio based and natural building materials that are part of my research. And specifically my question relates to materials that can be mined and curated directly from nature I call it sometimes farmed building, or in other words, the same. Non-commodified, right, non-commodified building materials that cannot be patented or cannot be so easily made into building products to inform a new industry. How do we tackle these materials because very similar to lime, clay is a natural binder that does not require any heating at all. I see Jen Sara talk about lime and I feel how I am talking about clay with this passion about its high growth thermal properties and its lending abilities and how it is a natural binder, which is permeable and breathable and so how do we use how do we develop a model for non-commodified building materials. Well, I think, you know, you raise a great question for us we talk about plant and mineral based building products, and that's a whole suite of materials that are being explored by a bunch of different people in different areas of the world and you know if we think of alternative models of production, the bespoke handmade house that uses the clay from the site that is built by the owner of the land, you know, with their friends that creates a sustainable healthy place to live is part of that vision I think it's not that we're necessarily looking at creating new products and creating wealth, maybe wealth for some people not for the people, not like dial chemicals the devils, you know, we are interested in, you know, alternative economic models and so I think you bring up a very good point Stephen Stewart mentioned Chris Magwood and Chris Magwood talks about, you know, this space, you know, he talks about plant based and also mineral based products in a much more holistic way. We focused on hemp and lime because we think, because there's a lot of stuff to do out there but we think there are opportunities there where we could develop models and then also look at other kinds of plant and mineral based ingredients and look at analogous aligned parallel or reciprocal kind of evolution of building products that is part of this new suite of the anti-dowel kind of product, the opposite of what we have now. Right, I remember Chris in the podcast hosted by you he talks about tomato stocks and sunflower stocks. So all these small scale local resources, right, that we can and right the smaller scale we get the more socially sustainable we essentially are. Well, Alex Sparrow speaks about that too, you know, who's a big hemp lime guy in the UK. He talks about learning from our place and that has been historically the way we've built. We use the materials that are around us, that surround us, we build knowledge over time, and then we build with those materials and that knowledge and that creates a sustainable building and construction system. Yeah, I mean it has to be that way why do we want to be shipping all these odd things all over the place. Using people you know using people's knowledge, you know farming is not easy. It's not simple. And you know mining also, you know, mining of clay mining of these things requires technology knowledge knowledge of people in their hands and their minds and different kind of knowledge than we're getting at these higher education systems. And so, you know, working with people who have these, this knowledge to make economies that will support their, you know, their, you know, generations of knowledge and local communities. Yeah, it actually supports everyone versus the other model which is, you know this kind of proprietary model that happens in these, you know, caged factories. And then racist and yeah, not sustainable. Yep. They were coming up to just we've gone way over which is no surprise because the conversations been so great. And but I just want to finish on one question that I think can be very quickly answered. I was wondering about potential maintenance issues, but I wonder what these heritage materials of actually they're so durable there aren't those type of maintenance issues we might encounter. Yeah, I think it's, you know, John sir you have another presentation. I do. Yeah, I do. I'm going to interior designers today to and interior designers because we have to work together actually we have to work closely together to make this big change. Yes, so repairing hemp line hemp line as it as it ages the line becomes harder and harder. It returns to its limestone like stone like features so they exterior walls in particular become more and more inert and harder and harder. They become very very durable. Similarly on the inside those walls are very durable. And so I think you can patch, you know with with lime and hemp, like patching if you needed to but the wall itself is becoming a better product. The more it's in the world which is kind of the opposite of these other products. And then linseed oil paint to yes mature over time. Okay, I just add one other piece to that like depends on the way that you're plastering so like on interiors. If you plaster in a way that burnishes that lime plaster. It can become waterproof. You know it can become much much more durable like again on ancient method if you look at ancient methods of Tatlid for instance it comes out of Morocco. It's a it's a compressed lime plaster it's a it's a wall that becomes almost stone like and water repellent just on its own. So, furnished with some soap. So, then you can wipe it, you can wipe it down all the all you want if you use something like lime wash which all of you could use on the rest of your projects for the rest of your life. Then the way to clean it is really with more of a brush, you know a dry brush or a dry rag not with water. So the maintenance just changes our behavior changes. So I had to just pop that in there. Yeah, no, important. And, okay, I just to thank you again, and make it I want you to realize that I think it was Stephen who had to jump off and he said, been on the health materials website, he felt like a kid in a candy store. I hope he visits often, but to thank you both and load of organization and Allison and John Sarah for really thought provoking and presentation. Just want to say, exciting. Yeah, I'm a long long from the M.L. program that just a piece I'm so happy to be with you all. It was really, it's a great joy for me to present our material to you thank you for inviting us. Thank you for having us. Take care. Have a good afternoon. Now my own students we reconvene on our other zoom link. I think. Okay, see you guys in a couple of minutes, we'll just take a couple of minutes.