Thrive In Construction with Darren Evans

Ep. 61 "We Built a House in 7 Days - and It’s Made of Straw!" | Modular Construction Explained

• Darren Evans

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In this episode of the Thrive in Construction Podcast, we dive deep into the future of sustainable construction with Paul Lynch from EcoCocon - a company leading the charge in modular, bio-based building solutions using straw wall panels.

Discover how modular construction is revolutionising the way we build homes — from two-day builds to large-scale developments like social housing and apartment blocks. Paul shares how EcoCocon’s prefabricated straw wall panels are not only fast and efficient but also commercially viable at scale.

We explore how offsite construction, pre-assembly, and circular materials are shaping the future of the UK construction industry - and how these solutions can help meet growing housing demand whilst hitting sustainability targets.

What you’ll learn:

  • How modular straw wall systems work
  • The speed, efficiency and cost benefits of offsite construction
  • Real-world case studies from across Europe
  • Why this method is scalable for major housing developments
  • How it fits with UK housing targets and Net Zero goals

If you’re a developer, architect, or policymaker looking for scalable low-carbon building solutions - this episode is for you.


LINKS
Paul: https://www.linkedin.com/in/paul-lynch-74660829a 
Eco Cocon: https://ecococon.eu/ie/
Darren: darrenevans.komi.io

Speaker 1:

The next episodes of Thriving Construction come straight from FutureBuild. Huge thanks to EcoCocoon. The space was great for chats, acoustics and even better well-being. It would also be great to work in a space like this.

Speaker 2:

That's a big side of the business for us is the health aspects. So we've had a lot of customers who've basically been mold damage or health, you know, asthmatic or respiratory diseases, so much so from the houses they have been living in that even their mental state is not hasn't been good. A good example is a lady I worked with for many years and and she had to move house after house and her kids were sick and she was sick and every building they went into they were like you know, really mentally kind of, oh there's mold here, we can't be in here, and it's just captured them so much that you know they kept moving around. And she inherited some money and she built one of these. Haven't heard from her since, but she had an impact and, you know, an input the whole way through on which materials were being used in the house. And we had a building company once I did many years ago and we only built natural homes and we built her house for her. Honestly, I haven't heard from her since Nothing, and they're perfect now the kids have. No, you know, everything's cleared up mentally and physically.

Speaker 2:

So sound-wise, health-wise, you're working with materials that are grounding. You sit, as you said yourself. You sit inside in a house like this and you're grounded, kids get grounded, schools built with this, the kids are grounded and you can actually see it. It's. It's really, really important, impressive, you know, and that's not a sales pitch, that's reality, that's human research done, you know it's like it's, it's the human impact of it. So, and then you have all the science research that's been done on these buildings and but I think the most important one is the human one. I've seen it many, many times and it's not just with straw, it's with most natural materials clays, lines, anything that's coming from the earth. That's makes sense. It's a grounding product and so and I've work in now I've been building houses in in scandinavia for 20 years and everything I've done is always does based around natural materials. That's how I found echo cocoon. 13 years ago. We started, we were straw bale builders and we found echo cocoon and went well. This makes it much, much easier and it does.

Speaker 2:

And I just worked with log buildings, wood buildings, everything and restoration projects, and even with an old log building 200, 400 years old you walk in. It's the same feeling as this. It's calm, it's just got that grounding feeling and for me that was always the pull. I want to work in buildings that aren't buildings. That doesn't have this impact or this pull. Later on came all of the climate stuff and energy efficiency and all, and it just so happens that these materials cover all of that aspect also. So for me, when I started, it was always around the health of the materials, the health of the. You know how good they were for the environment, how good they were for the inhabitants and how nice they are to work with. For a builder to work with. It's just fun, you know.

Speaker 1:

So, yeah, that's that's kind of where it came from what are some of the misconceptions that people have when it comes to this type of structure, especially things being made from straw and well, I, I would say it stems back a little bit to the three little pigs.

Speaker 2:

You know, um, that's the first misconception and I'm not sure if that was a propaganda done a long time ago by the brick and concrete industry. You know, let's bring out this story, but it was around a little bit before that. But yeah, I mean, there are the things you know, the simple ones for today, the simple ones, I think, for you know, the everyday customer is things like mice and rodents. Is it going to moles? How do we know it's not going to fail in some way? What's the fire resistance? Surely it's going to burn, you know. And then you have to.

Speaker 2:

Yeah, you can explain it all very simply. I mean, they have found straw in the pyramids, they have found straw in buildings 4,000 years ago. So you know, it's been around as a building material, it's been mixed with clay for a long time as a, as a fiber in the pyramids, in these buildings. But realistically, you know, the oldest house in europe today is in france. Uh, it's built in montagis, just outside paris. It's still being used today, actually, by the straw bale association of france. Now, they took it over many years ago when, when it was uh, there was nobody using it and they've opened the walls on that. It's 100, almost 110 years old now and it's like the straw on the walls you see here behind you.

Speaker 2:

Really perfect, still golden. No smells of it.

Speaker 1:

So the smell of the structure is still a pleasant smell.

Speaker 2:

Yeah, still the same, as I asked, like a pungent dampy, kind of moldy, still the same, and that's the key. I mean, you know, the oldest buildings we know today with straw still being lived in are in Nebraska and they're roughly about 140 to 160 years old it's. It's not 100, sure, with some of them. When they were built and they came from when the railway lines were being built in in the US, they were waiting for the railway lines to come to Nebraska with the woods to build the houses. Winter was coming, the guys taking in the straw and doing harvesting, they basically needed a house. They said I, we just take the big jumbo bales and they built load-bearing straw houses, no wood roof structure, no, so there's no wood, no whole thing. Like you have the structures here. It's one of the older methods. It's called the Nebraska method. It's literally a load-bearing straw bale structure, like Barbara Jones has done many of them here in the UK.

Speaker 2:

And then you came along the hybrid versions, using wood or using other materials and filling it with straw, and that's where Echo Cocoon basically came from. It's Demantis Surkis was his name. He was the guy who invented it in Lithuania 17 years ago and he basically was a straw bale builder, but he had the idea, like many of us. I started thinking about it that when I found Echo Cocoon, we were actually thinking of making our own straw elements. And then we found Echo and thought what's the point in reinventing the wheel, let's run with what these guys have ruined. But the mantis kind of came up with the idea of making straw walls, uh, in elements form, so that it could become faster, because he had quite many houses to do with straw veils and it takes so long, you know, and you're dependent on the weather all the time. So this was a kind of an experiment 17 years ago that quickly kind of caught on in, in that there was a few people who went, oh it's a great idea, let's put some investment into this and let's let's try to build it up. And they made a small factory which became a slightly bigger factory.

Speaker 2:

And then I think that's about where I joined in in the finnish markets they, we, we asked them for some uh certifications that they had done for straw bale buildings that we were doing in Finland. And they said, well, we're coming to Finland to a fair like Future Build a Finnish version, and said, can you join us on the fair? And we joined them and a couple of customers we had who were doing straw bale walls, straw bale houses, saw this and went, hey, we'll do this. It's modular, it's simple, it's faster, it's easier to do, made more sense and it took off from there. So we I joined echo cocoon then as a representative in finland. Uh, they asked me because I spoke swedish. They asked can I do, you know, look after the swedish market if they get some stuff there? But they were just beginning to expand to markets. They had come to echo build, I think at that stage and you know I went to a few fairs like bow with them and they got european funding and were traveling around just trying to expand out of Lithuania into a few other countries.

Speaker 2:

And I ended up being at that time the sales network manager, kind of putting the networks together, finding people who could sell in different countries for them. I was on the board for a while. My own company got busy in Finland and I kind of stepped off of the board and then, when I stopped my own company a few years ago, they asked me to join back again and kind of went back into okay, can you be the sales manager again, network manager. And now I'm kind of doing business, business stuff, with. A lot of the people we're working with were traditionally eco builders or architects interested in eco design who just said you know, I'm in bulgaria, can, can I sell your panels there? And we just kind of picked off people who were interested. And now today it's becoming far more professional. We're actually working with professional salespeople or people who have been working with straw for a long time, who have their markets kind of cornered in their countries and we're training them up now more in a professional sales manner, and the internal capacity of the company has grown. We have a brilliant impact investor who came in in 2019 and has grown it to a completely different level altogether.

Speaker 2:

And now you know, we've gone from small extensions, small houses, to 155,000 square meter logistic center in Holland, which has been built at the moment with 42,000 square meters of our walls being used on the outside of it. It's the biggest log logistics center in Europe. We have a 12-story apartment building just been the roof has just gone on it in Sweden. It will be finished at the end of this year All our walls on the outside. We have a 14-story apartment building coming in Holland also 90 houses coming in Holland. We have, you know many, many big developments and many architects offices from around the world who are the biggest architects offices who have. Now they see the impact that biobased materials are having on the market and they've completely changed the way of doing things. So we've taken straw in its traditional natural form and just created something that's more modern and kind of makes sense to uh, fits into the norms of regulations and highly tested, highly certified, and that's where we see we can make an impact.

Speaker 2:

Now we aim to make an impact. Uh, we, our goal is by 2034 we want to be producing about 1 million square meters of walls a year, which is a big impact. But it's actually a tringy impact on the total amount of square meters of walls being produced in, let's say, europe, which is about 200 000 or 200 million square meters of walls a year in roughly in just in Europe. So that's not even like 1% if we're producing 1 million square meters a year, which is huge, and that 1 million square meters we calculated it opens up to. About 25 factories would be needed and you'd be needing to produce two houses a day from each factory. So you know, if you break it down, it's like that's not a lot actually. I mean 1 million houses a day from each factory. So you know if you break it down.

Speaker 2:

It's like it's not a lot actually. I mean, one million square meters is about what is it? 80 000 houses in the whole of europe, it's actually not a lot. It's not a lot, is it really? No? So if you, if you think that just the uk alone needs 80 000 houses a year, you know that's, that's what the shortages is in most country. Ireland is the same. It's like we need 80 000 new homes every year. Nobody's able to do that.

Speaker 1:

Yeah, so yeah so if we look at some of the barriers that we've got, we just want to. I just want to run through a couple of things really quick. So if I got a lighter and put it to the wall, what would happen?

Speaker 2:

basically nothing at the moment. We, to put it into context, uh, I mean, you'd singe the outside of the wall. Yeah, there's loose material and that's the loose surface of it. We just but it will char. So no flame, just a bit of, just a bit of smoke and a bit of smoke and let it fit fine our latest fire test, which is only about two months old, was basically singeing or burning these walls.

Speaker 2:

Again in a new chamber we had one member or membrane on the outside. We reached 45 minutes uh rei on it and that's a bare straw wall. It was actually 52 minutes before it fell out of the chamber. Our wall was still intact. It was the actual holding pieces in the chamber that collapsed and fell out. So we reckon we could have got to 60 minutes if they hadn't failed, but of course that's a fail in the terms.

Speaker 1:

So what's the science behind? Can you just briefly sum up the science behind why it just doesn't catch fire?

Speaker 2:

Well, it's the same ingredients as wood, so you're looking at a wood product. It's cellulose based and it's so compact I mean it's 115 kilograms per cubic meter compressed into the wall. So if you just cut a hole in this in the morning to put a, let's say, a ventilation pipe through, you'll fill a 90 liter bucket of straw just with a tiny hole. It's so much stronger. So you're looking at I mean there's a statistic I heard that you need 15 to 17% of air for a wall to catch fire. So that's why the density is so much. And in that same statistic I heard that you know, with a highly compressed straw wall you've only got about between 5 and 10 percent air. So you're missing that air part. And I suppose a simple way to look at it is if you take one magazine and try to open it up and you'll burn it easily, and if you take a stack of magazines you won't burn it. So it's to do with the compression. Plus.

Speaker 2:

Straw naturally has silicate around the stem, so it's like which is a natural fire retardant itself. That's nobody spraying it with anything, that's just natural. So it has its own capacities to withhold that and then that's just a straw bowl. Then you add your materials to it. Add clay, which doesn't burn. It's an A-class fire material. To the inside, add your wood fiber boards and your membranes. Your membrane makes it airtight again, less air going through and we can get up to 150 120 minutes. Both sides fire resistance on it. So that's one key to it being fire resistant. And it's as I said. It's the same as as wood you burn. You will char the outside of it, but maybe a half centimeter in and then it stops no but in the fire regulations it's still in.

Speaker 2:

In all countries it's still classed as an e fire rating and this is down to the smoldering effect, and this is something that I know a lot of countries are trying to re-regulate. Um, so they're looking at. Why are bio-based materials considered e-class because of the smouldering when we know that they don't burn below this surface? And that's the same at word.

Speaker 1:

Yeah so the next question then is when it comes to, um, just building a normal two up, two down, or two down, three up type of property and then built en masse so a large developer, is it possible for a large developer just to build these out One hundred?

Speaker 2:

percent it is, and we're showing that now in a project currently underway in Holland. It's 89 council houses, so they're basically two-story or semi-detached homes, all built with eco-cocoon. There'll be 40 built this year and 40 built next year all pre-assembled walls in a pre-assembly factory. So we're shipping our walls to a company there who has a pre-assembly factory and they're assembling them all into large walls like this and then lifting those walls in and site, which means the speed of build is very, very fast.

Speaker 1:

How long then does it take to build a single dwelling?

Speaker 2:

So if you're looking at a detached dwelling, if you say three bedroom, four bedroom, yeah, let's say 100 square, 150 square meter wall surface, you'll have all the walls up in a maximum of two days. If it's pre-assembled off site, that would include the windows, doors, outside material, inside material, everything done coming dry to the site, pre-assembled with a crane. If it's on site assembly, like we did with this pod, just screwing them together on site, it's pretty much the same time. But then you're you're having to cope with weather conditions and stuff like that.

Speaker 1:

So there's, there's a difference that was going to be my next question. In terms of weather Surface. It rains quite frequently in these aisles, yeah, so can you only install it on a dry day?

Speaker 2:

In principle it's good, but I mean that's the same with any wood material. I mean we can get deeper into a conversation about that. I mean it's even the same with concrete and stuff which yeah, I'm not talking the torrential rain, I'm talking like the Drizzle is possible to do. Yeah, because if you think again back to farming, you look in the fields and the farmers have all the bales stacked on top of each other and have a little cap on the top of them with maybe a tarp over the top and that kind of roof shape. All of those outside bales are getting wet, but actually it's only the surface and it's kind of running off it Because wet, but actually it's only the surface and it's kind of running off it because of that compact.

Speaker 2:

Yes, now it's different if it's driving rain, because it can get into the center of the wall, which is uh, which then can become hazardous. But a little drizzle is okay. We don't recommend it still, but it's okay. You know, I've built over 25 houses now in ireland. Sometimes in november, december, they've been built. The key is, you know, it's getting the wall up because we use the membrane on the outside. It's that this makes it already airtight and weathertight. So you're getting a wall up quickly and you're covering that wall as it's going. So, as the build is going up, you're covering it all the time. And if it does, you know, we have weather forecasts in America as good as they are.

Speaker 2:

They're fairly reliable, yeah, but they're fairly reliable day by day, so you can actually see what's happening and you know, like any other product I mean, if you're using a wood uh, wood wall, like a wood framed house, you're still not going to build it in the rain and torrential and nobody would do it they say no, we're not working today, it's not possible. It's the same process. So you're looking and we do get you know one or two days or three days of good way, good enough weather that you can, that you can build in, and it's. It's just been aware. I mean, it can be a longer day that you may need to do. No, you're not going to check off at three o'clock and the walls are not covered. You just have to prepare your crew that this is the way. It is the very big key.

Speaker 2:

The difference with, let's say, timber, frame or block or anything is the key. With modular building and this is modular building is the process. You put the walls up, you have all your roof material, you have your. You're not going to take a break of two weeks between putting the walls up and the roof on. You want everything there and you want to get it covered as quickly as possible. So your two up, two down or your council house in principle can be weather tight in a week, and that's including windows and I've done this on site. Such a professional crew maybe one or two carpenters, myself and some helpers, and it's that simple.

Speaker 1:

It can be screwed together really quickly, so it's not massively resource intensive in terms of manpower and stuff.

Speaker 2:

No, no, no, and I think the way forward, as you know, if you're talking about these bigger developers who are doing these you know 100 houses at a time and they want to get into this I think the principle here is to develop in each country with a company where you would have pre-assemble option, and there's many companies now. We are now doing this in about seven countries already. It's not Eko Kukun doing it, we're just facilitating a local company to do this. So the key there then is you know, we have now, for instance, in Finland, sweden, holland, denmark, france all of these countries now have pre-assembly option. So we're shipping our elements to pre-assembly companies who are then offering for the full project.

Speaker 2:

We're offering for the walls, the roof, the windows, everything installed, and they're coming and installing on site with this and uh, this is a really good option for the big developers, because they don't want to pre-assemble the walls, they just want to buy the pre-assembled walls from somebody else. So this is something that is now developing for us very clearly on the markets, and it's become a very clear point that this is an area where our partners, our long-term partners, see a business opportunity, can develop more housing, can ship it anywhere in the country. We're just starting this with a US partner. He's based in New York and he can't get everywhere in the US, but with a pre-assembled factory he can now take orders, ship them out and have local people just click, click, click everything together and this is a really viable option.

Speaker 1:

If someone wants to build a net zero house or what they may determine as a really sustainable house. This ticks a lot of boxes. Yes, One of the boxes that I'm interested in just finding out a little bit more is the sound and the air permeability. What types of results can we get in sound and in air permeability in this type of structure?

Speaker 2:

Well, the sound one is actually, as you can see, we're sitting in a sound booth, basically. Yeah well, the regular wall structure that we have is hitting about 54 decibels. We recently did a whole batch of sound tests, acoustic tests, which we can reach now, depending on the various materials, up to 61 decibels, 65 decibels. And we have worked with a really good new product on the market which is EWS E-W-E-S. It's a sound screw with a spring. So it's basically a gyp gyp rock screw with a spring on it, but the spring helps the gyp rock to move away from the wall slight bit, creating about 16 decibels more on top of what we're doing. So if somebody was to use, let's say, gyp rock finishing on this wall and they use these screws, then you can reach up to another 16 decibels. But we even surprised ourselves and we surprised the sound chamber guys in the sound test, because you know it's a solid concrete wall where they have this little chamber and they set your wall in and we actually reached higher decibels the highest that you can get, which was 65, which means we probably would reach more and we surpassed what the actual, even concrete wall was with this. And so we just have our walls and and we, we know what the decibels are on them and they're. They can be minimal, but then when you start to add the different layers to it, we can, you know, we can showcase how high we can go, and so, very high on on the sound and the air permeability is similar. It's we. We have concluded that, uh, it's similar. It's like we're taking what we have in our walls and, depending on the materials you use to finish your walls, you can reach extremely high levels. So this is a really good thing.

Speaker 2:

Actually, there's been a couple of sound studios built for that reason, and I know I can't remember the band it is now, but I know in the past I'm nearly sure it's the Chili Peppers, but I'm not sure but they built a sound studio from straw as well for this reason, but of course, you're going to put materials on this when you're finishing. Yes, I mean, this is very, very dense. It's a dense sound, you know. So I built a sound studio for a sound artist in Aalto University in Sweden or in Finland, which is still available at the university today, and they put reed boards on the inside of our walls and you literally could not hear anything and we dropped it in the middle of helsinki, where all the trams and everything else we're driving past, nothing could be heard in.

Speaker 2:

So I think you know, yeah, we reach really good, good levels and that's why it's very popular for schools. For instance, we have, uh, had the human feedback from schools, from the, the teachers. So this is for classrooms, right, classrooms, yes, classrooms away from other classrooms, but yeah, everything is just so much the sound and the teachers come back and say that the students are less, you know, less energy, they're like, more calm, they're more concentrated, less distracted, less distracted.

Speaker 1:

In those classrooms the lighting was also taken care of, the ceiling, sound insulation was taken care of, but it's the again it was we talked to start this natural grounding effect and less tired from the students okay so you know, think about this in an elderly people's home and a hospital, in in these environments, where it just makes sense no, so I'm not sure at the moment, paul, that you have got anywhere in the uk where someone can just come and have a look at an example of a structure like a almost like an innovation park or a demo property or something like that. Have you?

Speaker 2:

there are well, there are, and a war a few places, um, I know a can had. Uh well, nhbc we're we're dealing with in mormon, that's the insurance site and and certification side. So we're actually aiming we're aiming to certify with NHBC this year so that builders and developers can see that it's been certified. There's a lot of the houses, the housing estates, have been built under NHBC and insurance, but there's I need to talk to George but I think it's NRBC which is it was a hub, nr Walls, a room, george, but I think it's NRBC which is it was a hub and our walls of all as room like this was there and people could come and touch it and see it.

Speaker 2:

I know ACAN have a lot of our panels and stuff and again, what I talked about, how we're going to be developing this year in the UK there is a organization company that we're joining with and they will have this pod and a couple of other things going to them and that's coming about q2 in this year, so four or two this year. So you will see a large development happening and fortunately I can't talk about it right now until everything is, yeah, it's ready.

Speaker 1:

You know, start training is done and everything is ready to launch, but so but there's exciting times coming now in the uk, so yeah, well, I love speaking to you and I do love this space. It's really difficult to describe just how you use the word grounding and I found that it is a really good use of that word to say that the smell, the noise, the feel, everything within this just feels comfortable. Yeah, um, you use the word natural in terms of natural products and and natural things and and it does it feels the natural to sit in here. It doesn't feel forced in any way, it doesn't feel uncomfortable in any way.

Speaker 2:

It's uh, it's lovely yeah, I, I totally agree. I mean, this is why I love working with these materials and for me, it's easy to sell. It's a, you know, it's a pleasure to work with a company like this also, who've got a really good social. The way we work with you know, their social ethics within the company are are very are also as pure and natural as the, as the, the product itself. So our values are very important to us, how we do things, and I think you'll find anyone working with these materials, or even the builders who begin to work with them.

Speaker 2:

They don't really want to go back. They start to work with these, they go. Can I do this again? Uh, because it's nice, it's easy, it's fast, it's efficient, but it's the material itself catches them. It's fun, you know. So, yeah, it's pleasure also talking and thanks for choosing us for the pod. It's been, uh, it was a nice connection, I think, with the, with the whole fair, for us to do this. I'm maybe delighted to do it again and work with you again, with your team. It's very cool.

Speaker 2:

Thanks, man. Thank you Appreciate that. Yeah, no, problem, paul.

Speaker 1:

there's going to be people listening to this that will be really interested about learning more and getting closer connected. We're going to put a link down at the bottom of the podcast to the website, but can you just give kind of like two maybe three different actions or different things that people can do just to connect themselves a bit better with, with eco cocoon and and um and what they're trying to do?

Speaker 2:

I mean follow us on on the medias and and the website. The website is amazing, and we have a new website coming in the summer, uh, which is even going to be more amazing, and we're all over social media. That's generally where most people find us. So that's, that's. That's the easy point I'd like. The action that I'd like is education. So for the governments, for the legislators, for the training schools who are training up new carpenters, new trades people, just be open to accepting that. You know there are a lot more materials out there than what we have been taught to use conventionally, and these materials are fantastic and it's straw, reed, iscanthus, hemp, you know, mice and there's just so many things out there clays, limes. But for those educational boards to think about training up these people, because this is the future, this is where we're going. And you want carpenters and treads people to be walking onto building sites and not going oh, what's this? You want carpenters and trades people to be walking onto building sites and not going huh, what's this? But going, wow, I know this. I did training around this in school and this is happening in Scandinavia already. So the school's there, it's the law now in Denmark and Finland, sweden, that you need to train in biobased materials. And three, four, for the customers, for the clients, for the architects Again, opening your mind, but ask the questions now, you know.

Speaker 2:

A prime example is, you know, a normal customer today going into a shop to buy paint, for example, as a simple example, or installations. If they just ask for insulation or just ask for paint, they're going to be given the usuals. But if they ask for an eco paint or a sustainable option, they'll also be given these options because they're there in the stores, just they're not the main product anymore and we just by asking that question, you're boosting these domain products. There's more of them going to be sold, there's more information that customers and the sellers will want to talk about it more. And these are just simple actions going forward.

Speaker 2:

And when you see these, open your mind, it's as I said, they're here to stay and you're eventually going to have to see them. And for me, that's the big thing is teaching kids. You know, building schools with these building deckers, showing people that these materials are normal, and get the kids involved. So when they're growing up to build their houses, they're going oh, I know, this material, this was in our school, this is, you know, simple, simple things that we can then boost ourselves forward with these materials, and that will familiarize all of these, because we don't have to be afraid of these. These are solid materials. They're going to last hundreds of years, they're not going anywhere and they've been around for thousands of years. They're just coming back now, and so that would be my kind of advice on all daisy. So