Laura Reiley 0:00

What if the old building next door could become the one going up down the street? Felix Heisell explains circular construction, the practice of designing buildings to be taken apart and reused instead of dumped into landfill. Felix, so good to have you here today.

Felix Heisel 0:17

Thank you very much for having me.

Laura Reiley 0:18

All right, well, so let's first talk about, let's define some terms, because I know that that's always the uh uh well or or a diagnosis. So kind of what do you perceive is the biggest problem in uh building the way we currently do?

Felix Heisel 0:33

Well, if you look at the industry, construction, in infrastructure, buildings, all of that together, um, we're the biggest polluter in the world. If you look from at a building from the beginning of its life, from the extraction of the materials all the way through operation till the end of life from the colour. Transportation of goods, etc. If you add that all together, then uh the industry is responsible for 50% of resource extraction from the Earth's crust, about 40% of solid waste generation, and 42% of um climate emissions, so greenhouse gas emissions. Um so that's that's that's immense, right? And we really need to change the way we operate in this industry.

Laura Reiley 1:18

But obviously, if we're cruising towards 10 billion people pretty quickly, you know, we need places for them to live, places for them to work, so we're not gonna stop construction. So I guess what are the alternatives to the way we're doing it now?

Felix Heisel 1:33

Well, what we're hoping for and what our work at the Circular Construction Lab tries to do is shift from the current linear operation of take-make waste to a more circular model, um, which was the standard for thousands of years before we shifted in maybe the last hundred years to a to this extractive model.

Laura Reiley 1:54

So, first hold on, let's define circular in that context. That's I think that I I think most people probably have a good idea, but just so we're all talking about the same thing, what do you mean by that?

Felix Heisel 2:05

Well, circular is essentially a closed loop economy, right? So materials aren't taken out of the ground to then be used and then thrown away, which is the standard in most of our economic operations right now. But really we talk about reuse as the most um successful circular strategy. And then of course there's recycling, which is something that we all know about, which has been promoted by the industry for many years now. Um and and many sort of small steps in between. We now talk about 10 Rs or three. I mean, we started with the three Rs, then there were six Rs, seven Rs, ten Rs, but essentially it's anywhere between recycling and direct reuse.

Laura Reiley 2:50

And direct reuse is the most successful of these strategies because Okay, so now going back to your the statement about thousands of years, that's what we did. I'm assuming you mean kind of from cavemen to to whatever, but if the it was a materials issue, right? So we were talking about stone, we were talking about wood. Is is our current uh problem or conundrum a materials problem?

Felix Heisel 3:16

It's not just a materials problem, it's also a it's an attitude problem. Ah, okay. That's one thing. Um it's um it's a question of how we build, maybe much more than what we build with. We build for um we build quickly, we build cheaply, uh, we don't necessarily use um high quality materials anymore. And so reusing something that's already trash when you start building with it is of course much more difficult than you reusing something that is a high quality material at the start, right? Um but then it is the way we operate and we construct by gluing things together because it's quicker than using a screw, right? And so it's a question of reversible um uh reversible fasteners versus um athesives for the right.

Laura Reiley 4:09

So I think one thing that I that I was reading about was the the idea of the embodied impact. So I mean I think most most people think of of um kind of the environmental impact of a building is the heating and cooling costs, the electricity, the whatever. So how can you kind of back up and talk about kind of the cost, the embodied cost of of a building?

Felix Heisel 4:31

So yeah, as as you said, we've been talking about operational emissions for the last decades when we try to solve the sustainability question, right? We we as an industry noticed something's wrong, right? The first the first solution was okay, let's try and bring down operational emissions through technical solutions mostly or through a better installation. Um and now in the most recent years, the shift is going towards let's reduce embodied emissions. And embodied emissions are all the emissions that are sort of necessary or or are caused by the production of a material, by the transportation of the material, by the actual construction of the building, and then by the disposal of that material at the end of life. Um and what we noticed is that these emissions are actually much more important when we try to do quick and drastic reductions in the emissions of the industry towards climate goals like the Paris Gold Agreement, for example, right? So if and and the industry um to meet, for example, I mean, if we still want to reach the Paris goal agreement.

Laura Reiley 5:44

We were young and innocent when we made that commitment.

Felix Heisel 5:46

If that's if that's the goal, right? We need to reduce uh the emissions from construction by 65% in the next five years. That is that's immense. Like if if you think about how long it takes to build, design and build a building, that's like the lifetime of one of these buildings, right? Um and so the upfront emissions suddenly start playing a much bigger role because on day one of a building's existence, when we cut the ribbon, right, these emissions are all in the air already. Operational emissions are the emissions that we're spending over the next 30, 40, 50 years of operation, little by little every year, right? And so if we reduce the embodied emissions, then if we change the way we built, we have a much quicker impact in changing. And then of course you have compounded issues that if you have a little bit less emissions today, that means over the next 30 years, right, you have less um CO2, for example, in the environment, in the atmosphere, and that makes a big difference as well.

Laura Reiley 6:48

So right now, what happens at the end of a building's life? Like what is the what is the uh the final chip the like the kind of geriatric building uh scenario right now?

Felix Heisel 6:59

Well, I mean we see it almost every day driving past construction sites or decon demolition sites, right? You have an excavator that like a dinosaur kind of crunches into a building, pushes that down to the ground, um, takes one day, two days to take down a residential structure. Um, and then to make it even smaller, we drive over it a couple of times with the excavator to break everything into small pieces, scoop it up and put it into a dumpster, and then drive that to landfill, right? Um there is of course the ambition to recycle, and so we pull out some of the metals by going over it with a magnet, um, to kind of get the ferrous metals out at least. We we have the ambition to recycle some of the mineral demolition waste into concrete aggregate. But all of this essentially is downcycling, right? Um, because um, I mean that's a different conversation, but recycling concrete still needs new cement to glue it back together and the emissions come from the cement and not the concrete. So it's what are we really helping here?

Laura Reiley 8:06

We're creating. Um, so what is urban mining? What is that uh unpack that concept?

Felix Heisel 8:11

Yeah, so urban mining is um the the question what can we do with a built environment that is not designed to be reused? And that's essentially what the current condition is, right? Most of our buildings right now were designed for eternity. Like the architect, the client, we all thought, let's build something, and the end of that building is usually not part of the design process.

Laura Reiley 8:36

I'll be dead by then. You know, we don't need to think about that. Well, I'm I think there is a question.

Felix Heisel 8:41

I would do the same. I wouldn't want like you know, but but it's my legacy, this building. Realistically, no building stands for eternity.

Laura Reiley 8:49

What is the average life? I mean, is it is it even possible to say like so? Let's say for a high-rise, like a downtown big high-rise building, is it a hundred years? Is it fifty years? I don't know.

Felix Heisel 8:59

The design intention is 70 years right now. Um the real service life of a building is less than that. We're somewhere at 50 years.

Laura Reiley 9:08

Is that because of changing tastes or changing building use for I mean, there are many different reasons.

Felix Heisel 9:15

Um many of them are economic, right? So if you have a rezoning, you suddenly can add five stories. It might be worth demolition is really cheap, right? And so it's it's usually worth taking down the building, building something bigger, larger.

Laura Reiley 9:31

Is it also about um kind of uh building codes changing and standards and and retrofitting is more expensive than that building?

Felix Heisel 9:50

Clients are asking for it, architects are are putting that into their repertoire. Um so that's something really positive that is happening. But still, as I mentioned, the the economics usually don't fully work yet. And so demolition is is still the prevalent uh solution if you if you want to clear a site to then do something else with it.

Laura Reiley 10:17

Um so relating that to kind of circular construction, um thinking about a construction site or a building environment as a material depot that rather than kind of a one-way path, how how sh how can we think about that differently?

Felix Heisel 10:35

Actually, let me um let me answer that question, your last question a bit more in detail. Oh, sure. Before I go to that, because urban mining um as a kind of counter concept to circular construction, then really is taking on this metaphor of or or yeah, the mining um concept, right, of mining, for example, gold. Right. If you go into a mountain, you want a gold nugget, you need to move, I don't know, a a ton of stone to the side to get to a gold nugget, right? And so in in urban mining it's the same thing. If you want to salvage something that is reusable in many cases, because it wasn't designed to be reused, right, you're still creating a lot of waste in the process to then get something out that you can that you can reuse. You have to cut things, you have to kind of yeah, break through things because the connections aren't reversible. And so urban mining is not necessarily the solution, it's sort of a process towards a better So it's scavenging, basically. Scavenging part of it, it's you can always I mean there's there's um there's a diff different ways of or different levels of deconstruction, right? So salvage would be you go and you take the floor out, that's an easy thing to do. You can reuse that, but you're not taking on the concrete slap, right? Um if you then uh recycling, you can do this, the the take take the steel out, the reinforcement out of the concrete, um, and maybe re-melt that into a new rebar. So that there's different levels, and if you fully deconstruct a building, then the goal is to really reuse components at their highest utility and value. And all of this is sort of urban mining. And then your can your question about circular construction kind of takes this to a to a forward-looking um vector. So, how can we design differently now so that we actually don't run into all these problems that we just described when we deconstruct the buildings in these buildings in the future, right? And so we would use different connection details. We would actually design with reuse or with deconstruction in mind. We want to make sure that these are maybe modular pieces that come out that can be reused somewhere else at highest utility and value. And so the the difference is really that once you understand that the built environment wants to be this deep hole, like then you're talking about asset management, right? So the wall becomes an asset, the wall bec has a value, and it can either be in this configuration where you're at right now, but it can also be in a different configuration by just unbolting it, moving it, and re-reassessing it or reassembling it somewhere else.

Laura Reiley 13:18

So for for let's say for something like the highest lead certification, are they thinking about this about the reuse so that when you're constructing a building, it's the materials used, but also what will happen at end of life for that for that building?

Felix Heisel 13:31

It's it's actually really uh encouraging. The lead five, which is coming out now, has a circular economy component and you get points for reuse, for material reuse. So there's there's actually quite a bit in the making right now to incorporate these ideas into the way we certify. Lead four doesn't do that yet, but the lead five does.

Laura Reiley 13:50

So talking about design for disassembly, who's doing work in that and what what does it look like? Give us an example of some things that are kind of new construction that's designed so that at the end of life it could either be repurposed or or easily, I don't know.

Felix Heisel 14:07

There there are there are some really interesting case studies. Umish, I'm gonna use one of ours. Um I think that's totally fine. Um so we we built uh what is called the Urban Mining and Recycling Unit. This is a um an office project um in Switzerland. Here in oh, it's in Switzerland, okay. Um and there the idea was really can we build something where all 100% of the materials that go into the building afterwards can come out again into either reuse or recycling or composting, right? If we look if we look at biological uh materials. Um and it was really interesting. It it required a different planning process because all the stakeholders needed to be on board and they needed to be on board much earlier than it usually is the process to kind of be inundated with this idea of the design extra.

Laura Reiley 15:01

I'm sure there are people that are working at odds that have you know very noble agendas but that are orthogonal to someone else's.

Felix Heisel 15:07

Yeah, so we needed a new uh a new planning process. Of course, we had different designs, but then every detail needed to be looked at, right? Um the in most cases we don't even think about it. Like we've always done it that way. And it's not a bad intention, but it's just you need to rethink why do we put silicone there? Why do we glue this tile down? Can we do this differently so that we can pick that tile up again in a couple of years?

Laura Reiley 15:33

So is it is it often things like issuing welds or glue or things that are thought of as permanent in favor of snap togethers or or you know, screws and like is it that kind of thing, or are there other i it is to some extent that, right?

Felix Heisel 15:50

We need reversible connections. Um that makes a lot of sense. Um other industries changed to that many years ago when requirements came out. I mean the car industry is is has a requirement. 90% of a car needs to be uh recyclable, right? And so you can't it's all clip systems now, for better or worse. Um But um we we don't have these requirements yet, at least not in the in the US. Um and so but yeah, we we're still using what's quicker or what's cheaper, and that's usually um composite materials, that's usually adhesives, um, and and those actually those two are kind of the the key problems. Right. So uh a composite material that I don't know has a a backing of uh I don't know a biofoam and an aluminum casing or something, and once that's glued together, you can't compost that biofoam anymore because it's mixed with aluminum. But you can also can't recycle that aluminum anymore because you have this bio. Exactly. And so then the whole thing goes to the top. So you destroy it. It was designed as a great idea. It it's it's quicker, you you have a product, you can control that product, it has great R values, great installation values, et cetera, et cetera, right? But the the end-of-life scenario wasn't part of that design process, and so it causes these issues once then all of these materials hit the landfill. And so we need new products, we need new design strategies. It the whole industry needs to rethink, and that's a massive shift.

Laura Reiley 17:25

So it sounds like more of an ideological change than some of the logistical shifts that need to happen. I mean, I read a thing the other day about how the American home architecture is going to change as a result of people being on these GLP1 diet drugs that our reliance are the our centering of the of the home in the kitchen or in a dining space is going to shift and and what would that look like? So the whole idea that like culture changes or our the what our use of buildings change changes over time, is that something that has to be kind of integrated into some of our thinking?

Felix Heisel 18:04

I mean, naturally a a lot depends on the client. If the client, and it happens more and more now, if the client comes to you as an architect and say, I want a building that is VOC free, for example, right? A lot of it actually comes through the healthy materials movement where where you actually don't want these cheap materials in your in your building that off-gas all these chemicals. And and so in the residential market, more and more we want biological resources that are carbon negative. Um, and so these requirements come from a societal shift. And that shift is really important and and helps all of what we're talking about here.

Laura Reiley 18:46

So you've you've built and exhibited some of this directly. There's the the the circulating matters installation. Can you talk a little bit about what that is?

Felix Heisel 18:53

Yeah, so what we what we did in that, and it's a small, really a small sculpture more, um, but it used um lumber that we deconstructed in a case study here in Ithaca where we took down a residential structure on College Avenue and deconstructed that building and then salvaged that lumber and used it to construct that that sculpture. And even though it was so small, it needed a full building permit by the city of Ithaca and it needed a full structural engineering report for that building permit. And so in the end, it allowed us to kind of play through on a prototypical level what would it mean to actually take salvaged lumber and use that structurally, which is not allowed in the building code. Right now we're not allowed to reuse uh lumber other than in c in decorative. I mean you can always take flooring. I mean, can you read it? Reflooring. Anything that's not structural is not a problem. But to actually build with salvaged lumber structurally is new, and and um so that really helped us to play through okay, what what would it take to do that um using that?

Laura Reiley 20:04

Are there new tools that kind of somehow digitally or like whatever assess structural integrity or like s like things that kind of lasers or or something that will give you the green light on on yes, this beam is is sound?

Felix Heisel 20:19

So that there is a that a lot happened on this in this field in the last year. Um the um and this is all because a lot of people across the nation understood that this is an issue, and so we have new policy, we have new code, and we have new tools about the reuse of salvage lumber that all came together in the last couple of months. So this is a really exciting field right now.

Laura Reiley 20:42

So so code and policy, is this at the federal level or is this state by state, or how does it work?

Felix Heisel 20:48

So um Dr. Anna Callis, who is the representative of um the assembly from Tompkins County, um, she proposed uh, with our help, a new bill that just passed the Senate and the House in New York State on the state level that allows the direct reuse of salvaged lumber in New York State. It's on the governor's table right now, and we're all hoping that the signature will come any day. Um so that's a really exciting moment, which would effectively immediately then allow, under certain conditions, the direct reuse of salvage lumber in structural applications. Um the International Construction Code just um went through a similar process and approved the use of salvage lumber in both residential and the International Construction Code for the 2027 amendments. Um those will trickle down because the state building codes are based on the International Construction Code. It's like a template, and usually every couple years the states will say, Okay, we're gonna go use that version now. Um New York is usually pretty quick. Adopting these other states are a little bit lagging behind, but over time this change from the international at the international level will trickle down on to the state levels. The US is tricky when it comes to building code because essentially the um local jurisdiction decides what is the building code in the city. Yeah.

Laura Reiley 22:19

So that's a lot of battles to fight.

Felix Heisel 22:21

The town and the city of Ithaca and Dryden, they all have different building codes. But they're essentially built based on the uniform code of a state. And so this will all trickle down over time.

Laura Reiley 22:34

How about on the deconstruction side? Is there is there deconstruction policy?

Felix Heisel 22:46

And budget bills are fought over very heavily in in New York, especially right now, as you can imagine, with reduced budgets. So we're working on that. And the idea would be that you'd have a template deconstruction ordinance, and if a local jurisdiction adopts that, the state would help uh, for example, with a budget for incentive programs at the local level that would offset the the cost difference to the owner between demolition and deconstruction. Um it would also, for example, offer funding for the infrastructure development that is necessary. So warehousing, I mean. Yeah, so you're incentivizing.

Laura Reiley 23:24

So you need the you need the carrot, not just a stick.

Felix Heisel 23:26

So and and um so that didn't make it through. But what what happened in the last couple of years is that we we in this case is crowd. Crowd is a policy advocacy group that I helped co-found in 2020 on the state level. Uh crowd is circularity reuse and zero-based development. Um as a group we have. So it's crowd with a zero, not an okay. And we uh we proposed a uh deconstruction ordinance template. And there's actually seven municipalities that adopted this now. The last one that did it was the town of Ithaca, which we're really proud of. But Dryden also has it, for example. The first one that adopted it was Auburn. Um all of these are adopted as resolutions, so those are not yet binding, not a binding ordinance, but a resolution. But it shows that these towns unanimously decided that this is the way we want to go. This is sort of an a vector of how local policy wants to move forward. And and it's encouraging because it helps us at the state level to advocate for these uh larger and then mandatory bills.

Laura Reiley 24:34

Well, so going back to the the uh reuse of lumber, so it sounds like there are some innovations. I think your lab is doing some using an a an AI tool to grade lumber. Um and is that it seems like that is the um essential piece of it, right? To make to give people peace of mind uh that that something is structurally okay to reuse.

Felix Heisel 25:00

Yeah.

Laura Reiley 25:00

Are there are there ways of bringing that thought to bear on other materials?

Felix Heisel 25:06

Um naturally, yes, that that is what we're hoping for. Um the um every material is very different, and so you can't just copy that idea one-to-one. But uh what we're what we're trying to do with Lumber is um so all of these new codes that we talked about already, they still require some kind of check, right? Which I think we are all in support of because you don't want buildings to collapse. You want high-quality buildings that are safe, but buildings that are using a better resource, right? A reused resource. Um and so um you can always do a visual grading inspection, which means you need someone that is certified to come and look at the lumber and then say this is grade one, this is grade two, this is select structural, to kind of go in these different lumber grades, which then have different applications in the building code. Um and uh what we're hoping for is to develop a tool that you can just use your your cell phone. So you don't have like a $30,000 equipment scanner that you need to buy, really low entry level that any contractor can use, but just pulling this thing out of your pocket and taking pictures of the lumber, and it would tell you the same thing. Because what we can do now with with uh artificial intelligence and machine learning processes is essentially understand okay, what are the defects, what are the sizes of these defects, and apply these visual grading rules the same way as a certified grader would do that. Um and we're having really, really great results from from this. Um and the the conversation that we're now having is of course, how do we certify a tool like that, or who would be allowed to use that tool?

Laura Reiley 26:49

And that's that's everybody's liable if it fails. And and then does it integrate with like CAD or some of the kind of design applications?

Felix Heisel 26:56

That would be the hope, right? That that you what what we have essentially with a tool like that is a much more transparent protocol. Like we know afterwards why is this wood graded the way it is, which you don't have if you just have a grade stamp. And so you could also say, well, this piece of lumber is better used, even though both of these pieces that I have in front of me are both grade one, right? You could still say this is better as a column and this is better as a beam because of the way the because of the location of the knot, for example, that you and and so you have much more transparency, and that of course you can bring back into design processes and and uh optimization processes.

Laura Reiley 27:36

Sure. All right, well, so we're we're running out of time, but I kind of want to ask, uh maybe this is not answerable, but like kind of what's the single biggest lever for change in this arena? You know, is it what's the what's the thing that's gonna get you to where you want to go?

Felix Heisel 27:49

Yeah. Um I don't know yet, otherwise I would pull really heavy on that one. Um I mean, what we're trying is to shift a whole industry, right? And so what what is clear is that we need all actors to work together on this. It's not a single university, it's not a single lab, it's definitely not a single architect or or client or owner that's shift that's a lot of people. We need to all go be on board. Um but then at the same time, as I mentioned earlier, it's an incredible momentum right now. Um New York City just passed some really exciting requirements um for funding through the EDC, um, new circularity guidelines, there's new markets appearing. That's that's a really interesting and important part. That of course all the wood or all the materials that we're salvaging, right, they need to go somewhere.

Laura Reiley 28:47

Sure, someone needs to want them. Yeah.

Felix Heisel 28:49

Otherwise, we can deconstruct all this as just creating a a massive headache in the warehouse and more cost, right? And so if you don't match demand and supply in this in this shift, uh it's not gonna work. And so we need to design differently, we need to deconstruct differently and then make that meet. And policy is probably the single largest liver, but um um and a a difficult one to to to move. And so we're we're trying to show through case studies. Yeah, and proof of concept so that the legislators can then convince uh everyone to be on board.

Laura Reiley 29:24

So Felix Heisel, thank you so much for having for coming today and uh being our guest. Um you are listening to Research Matters, and um you full episodes are on YouTube uh and everywhere else you get your podcast, and clips are on LinkedIn, Instagram, TikTok. Uh find us wherever you uh wander on the internet. Thank you so much. Thank you so much.