Mass Timber! Let’s talk.
We speak with Wekesa, an architect at BuildX, a firm dedicated to human-centered design solutions that prioritize environmental performance and local resources. In this episode, Wekesa sheds light on the environmental impact of traditional construction materials like concrete and
steel, which contribute significantly to carbon emissions. He proposes a game-changing solution: incorporating Mass Timber into the construction process to reduce our carbon footprint.
Wekesa emphasizes the need for a mindset shift regarding certain materials and highlights the potential of plantation forests as a sustainable resource. With Africa witnessing rapid urbanization, he urges us all to rethink our approach to construction. Don't miss out on this opportunity
to learn how you can contribute to building a better world.
This is the twelfth episode under the ‘Shifting Narratives’ program supported by the British Council SSA Arts.
*For the best experience, please use a headset/earphones.
[00:00:00] George Wekesa: Concrete is actually the second most consumed material on this planet, only second to water. And the fact that it's a material that significantly contributes to the carbon footprint.
[00:00:11] There's a reason why we need to think differently around how we build.
[00:00:18] Adrian Jankowiak: Wekesa George, thank you so much for joining me here. We know each other, it's been, it's been good observing where you've been going as well over the last few years since you've joined Build X in particular. So maybe we can start, you can give us a quick introduction into yourself and what Build X does as well.
[00:00:37] George Wekesa: Thank you so much. a Adrian. Yeah, it's been a while since we've been in touch couple of... I think five maybe years, I don't know, four years. So my name is Wekesa George. My background is in architecture. I studied architecture at the University of Nairobi, and I have been working with build X for the past five and a half
[00:00:57] I've worked on different projects, in the course of the five years, but now
I'm, I'm working as a mass timber lead. So heading all the projects that involve the use of mass timber in the design and construction and pioneering demonstration buildings that show the variability of the concept in the region.
[00:01:15] Just a little bit about build X, since we're talking about sort of the holistic
picture. BuildX is a design and construction company that's based in Nairobi. We've previously worked across Africa with projects in Zambia. We have a school in Sierra Leone. Projects in Uganda as well.
[00:01:33] We've been around quite a lot but I think now the intention is focused a lot on East Africa. Our buildings are primarily focused on an environmentally conscious approach, but also a human-centered approach. So thinking through how best do you improve the health and wellbeing of building users, how best do you encompass environment mitigation measures like climate mitigation measures through the use of low carbon materials, and how best do you include everyone in the construction process.
[00:02:02] And that's why we also work closely with our sister company, Buildher, who
train women in construction skills to have them work with us in our construction sites and ensure that sort of 50 50 balance with male female on our construction sites. That's our focus at the moment but with my role, the key aspects in all this is to look at the low carbon aspects, and that's why Timber presents that opportunity for us to do that.
[00:02:29] Adrian Jankowiak: Huge percentage of greenhouse gas emissions are caused by construction. Right. How are you guys at BuildX then going about that besides also the social good that you are creating? How are you looking at decreasing the impact on the climate through construction?
[00:02:47] George Wekesa: Yeah, so we started off in uh, 2019 looking at different solutions that can help decarbonize the construction industry. So as you mentioned, the construction industry accounts for a significant contribution to the global carbon emissions which is 40% and the materials that account for a big chunk of this are still on concrete, which we use predominantly in building our cities here in Africa. And I would say most of the world as well. Concrete is actually the second most consumed material on this planet, only second to water. And the fact that it's a material that significantly contributes to the carbon footprint.
[00:03:30] There's a reason why we need to think differently around how we build. At the same time, the continent is really growing at a very fast pace. It's the most
urbanizing continent in the globe which means that more and more new buildings will be needed. More and more infrastructure will be needed.
[00:03:49] And if we keep building in the same way, then the effects will even be
heightened. So we looked at different systems. How best can we reduce the carbon footprint of the construction industry? And one of the research led us into timber and we realized that it's a new material in terms of it's wide scale use.
[00:04:10] Yes, they have been traditionally built small scale buildings that have to the
test of time. But what we're talking about now is a solution that is as structurally applicable as concrete and steel. So having an engineered timber solution that can help you to scale building solutions.
[00:04:29] We realize, yes, it's something that is a solution that has been there for a
while, but this engineered products is what is relatively new in the market. And for us to normalize the use of it. We started off by doing a prototype, which was a 60 square meter prototype that we had initially set out at the different parts of Nairobi where we had visitors come in, touch, field, experience.
[00:04:52] And that way we managed to get a lot of positive feedback on the potential
because by doing that sort of experience or exposure visits, a lot of misconceptions were demystified. And at the end of it we now have a positive outlook of it. And we're thinking even of doing much more taller buildings with this material to even show the applicability of the concept at a high rise level.
[00:05:13] So that that's how we, we think of changing the industry. So we start with
small demonstration projects that show the viability of the concept. Seeing is believing. So as people come and see the viability of the material from time to time we hope to increase their appetite for this kind of a solution and then transform the industry afterwards.
[00:05:35] Adrian Jankowiak: So, like you said, this type of timber, mass timber- is kind of a new construction material and new methodologies. So just to clarify then, what is mass timber compared to timber itself?
[00:05:49] George Wekesa: Yeah. So Mass Timber is a collective term that refers to a range of products which are made from solid wood pieces that are bonded together either in parallel or in cross-section in alternating plans to form posts, beams and columns that have really exceptional strength comparable to concrete and steel.
[00:06:10] The most common type of mass timber is called cross-laminated timber which is made by gluing the solid wood pieces in cross angles to form panels that can be used for different applications. You can find a building that has, has been made out
of this product for the walls, the slabs, and the roof.
[00:06:30] You can use it for different applications in a building. The other products
also have different uses. So as you design your building, you become strategic in how you pick and choose from this area of master timber elements that can apply to specific typology. If it's a residential building, it's a commercial building, what funds do you need?
[00:06:50] What's the use of the space? So yeah, different applications require different Mass Timber elements.
[00:06:57] Adrian Jankowiak: Is there any resources that people can go to to learn about the different types of mass timber elements?
[00:07:04] George Wekesa: There's a lot of resources online but I would recommend a website called Woodworks. Even they have short videos on YouTube where you can even just Google what is mass timber? And then they start off explaining to you. The fact that it's a material that has been around for at least three decades now. There's a lot of information that's already circulating. Initially in the 1990s it was limited to use in Europe only but now we are seeing some emerging markets in, uh, like South America. We have established manufacturing plants in in Brazil, Uruguay.
[00:07:39] Here in Africa we only have two manufacturing plants and they are set up in
South Africa. And the reason why we are trying to build the demand for more buildings is to demonstrate that there is an appetite for this in the market. If in the eventually that we have local production set up in Kenya, there's actually a market for that.
[00:07:58] And investors are looking at seeing these kind of numbers. Would the market buy this product if I end up setting it up, or they're also looking at say at
things like, is there enough raw materials? Are there enough sustainably grown forests that can sustain my factory to be able to have a financially viable running factory?
[00:08:29] George Wekesa: Oh, the reason why we don't have local production yet it's because it's a material that requires you to carefully grow your forest to a certain degree. So these are forests that are monitored to achieve a certain specification for timber that can be used for this kind of purposes.
[00:08:46] A lot of times we get people confusing this with natural existing forests but
this is a solution that's based on plantation forests. In Kenya, we haven't reached that threshold where we would say we have sustainably grown our plantation forests to harvest and sustain such a factory.
[00:09:01] But other countries in the region have.
[00:09:04] So Tanzania have already done that. They had forestry programs back in the
nineties that allow them to grow their forestry potential. Uganda has done the same. So we now understand the potential that exists in East Africa from a regional point and not as a country, as Kenya.
[00:09:21] Kenya on the other hand has a thriving real estate market that would easily
take up this, this product. So it would need like a very regional, coordinated effort to have this in place. Since that is not sort of coordinated, we have first to demonstrate that it's still a viable product to really show that in the eventuality that we have local production set up, this is something that would work.
[00:09:47] There are no specific skills that really limit us to going to South Africa. It's more that they did the work about... in growing their forests first, and that's normally the first step. You need the raw material which we, we haven't reached there yet. And they've also had a bit of capital investments that have gone into the, the manufacturing process.
[00:10:11] I can maybe just talk about how the whole process works, just to make it a bit
clear. You have the forest. It is grown in a very specific way, monitored and, sort of quality checks are done every now and then to have it at a certain height and it's harvested at a specific time.
[00:10:28] And it has to grow to certain radius, also to have it easy to handle with the
machines in the factory setting. So once that is done the timber is harvested, then it goes through a process of like the primary processing. There's the sorting, there's the kiln drying. They dry to certain moisture content level that is suitable for making masks in the products. And then there's what we call finger jointing where you essentially join pieces of wood to have even longer pieces. And once you have that, then you can layer them out, apply glue on top, and then alternate the layers of lamination. Or you can have them in parallel depending on the product that you want to, to produce. So for cross laminated timber, you'd have to alternate the layers in 90 degrees.
[00:11:17] You also have to do it in odd numbers so that the direction you started with is
the one that you end with. Then the third one would still be the direction of the one that started. And the same applies to five, the same applies to seven. So once it's made into a product, it can now be strength graded. Also depending on the design of the building, the different treatments that are done in the factory to, to make it suitable for the building site or the specific design.
[00:11:45] So it's cut into shapes that would go into the site in sort of a kit of parts, like an Ikea set which is is easy to assemble on site. You only need screws. Basically if you're doing a small project and you don't need like the big cranes, you just screw it together. It takes a really short period of time up to 70% faster than traditional building methods.
[00:12:06] Adrian Jankowiak: So you've got your panels of wood at right angles. Is there a particular reason there odd? Is it a strength reason or an aesthetic reason that you've always got odd numbers?
[00:12:16] George Wekesa: So when you think about the reason why it's called engineer team is actually, it's a very simple engineering process that happens from what we know as timber. So when you think about timber in one direction the strands of wood, they only go in one direction. When forces are applied on the sides of the panel there's a weak point of the center for each to sort of crumble.
[00:12:38] But when you have other members going in the other direction, it means that there's a counter force to now mitigates this. And how can it alternates in terms of having it in odd numbers helps to ensure this sort of dimensional stability from a structural point that gives it even more stability than when you have it in even numbers.
[00:12:59] With even numbers, there's a way in which they can start sliding on top of each other in a way that won't be structurally sustainable.
[00:13:07] Adrian Jankowiak: I guess you also know that if there's more going in one direction, then it's in theory stronger that way as well. What kind of things you showed me before we started recording. You showed me the office space as a prototype that you guys have created. What's the potential here in terms of building and what sort of scale buildings are you expecting people to be creating?
[00:13:30] Because we've seen some people are already creating skyscrapers out of wood. Is that something you can foresee?
[00:13:37] George Wekesa: Yeah. So the thing is with growing forests along the tropics, the trees mature faster than in places where this technology has been around for, for a very long time. So take an example of a pine wood species. Pine would take up to even 50 years to grow in North America or in Scandinavian climates.
[00:13:59] But it'll take 15 years or 10 to 15 years along the topics. So you can see that
we have certain geographical advantages in thinking about this material and, and thinking big about it because we can be able to produce it even faster. Our existing prototype is an exhibition space. So at this point, it's a tool for raising awareness.
[00:14:21] We've not really designed it to optimize on the structure, but the structure
that we've used to design it can hold or sustain a building up to six stories. So the same thicknesses that you would find in our prototype would allow you to build without changing the thickness up to six stories.
[00:14:37] And beyond this, we are thinking of having even high rise buildings to show the application of the concept at that scale. And the reason why we're thinking of
doing that is- it's a mindset shift that we are trying to inspire where timber has been known to not be structurally strong, susceptible to termites.
[00:14:57] And one big misconception is around its fire resistance where people think it
just burns like a piece of paper. So what we're talking about here is the massive pieces of wood. And when you look at a, say a setting like a campfire, you always need like smaller pieces of wood to light up first before you can light the big one.
[00:15:18] It'll take you a long time if you were just to take a match tick. And actually,
if you try to light this big chunk of wood and that's the image should have when you think about mass timber. So, but in a eventuality that actually catches fire, it burns in a very predictable way which is the outer layer's char and suffocate the oxygen.
[00:15:39] So the killing the fire and preventing it to penetrate into the inner layers.
And at this point there's a lot of research that has been done to estimate accurately what that charring depth could be. So that, these products are designed with the inclusion of this charred layer.
[00:15:57] And you can remove the charred there and add on another lamination once the fire is put out so that this sort of predictability and the way it's chars and burns can be very accurately estimated and accounted for the design such that you won't need to worry about the fire performance of the building.
[00:16:14] We also want to blow people's minds somehow by having it at the biggest scale because people would only expect to see timber houses or buildings at maybe at
the height of like three stories. But not like 18 stories. So it's a way to like, really like radically change the mindsets completely.
[00:16:32] Adrian Jankowiak: Great. You talked about these trees coming from plantations and also there being a lack of the right tree, right timber supply right now. We often hear that trees are important to curtailing climate change. So how does this link in with cutting trees and then trying to prevent climate change?
[00:16:55] George Wekesa: So, we are increasing the value of forests so that we make them stay forested. We are providing a building solution that would enable you to earn say 30 times more than you would with your normal utilization of wood which is furniture, maybe a few trustees on buildings by this high value product.
[00:17:21] And the reason why I think there's normally confusion about the cutting down of trees and this solution potentially causing deforestation is because there's
normally not that distinction of natural forests and plantation forests. So you would essentially grow your buildings the same way you grow your food.
[00:17:42] So you'd leave the natural forest intact and untouched and then you grow new trees. But by doing that, as we know trees, as they grow, they sequence to carbon which they store when they're used in durable products. And by using wood in buildings, you substitute or you offset the high carbon emissions that would've resulted from steel and concrete.
[00:18:08] So you see there are different ways of looking at this where yes, you've cut down the tree, but you've stored carbon in it. And carbon emissions are what contribute to climate change. And the construction industry is what contributes the most to climate change. So it's the industry that you need to focus a lot more our attention to actually bring down the carbon emissions, which would significantly reduce the carbon footprint of construction.
[00:18:35] Adrian Jankowiak: Nice. Tell me more about this prototype that you've made in Nairobi and what it's there for, and what it looks like, how it works. What's the purpose?
[00:18:45] George Wekesa: We initially had it in a different location in Nairobi. It was a culmination of our research efforts that we started in 2019 where we realized since it's a new material in the market, we had to have a built prototype to actually show how it works. Then we were using it as a research piece, so to get feedback from the market. Know how best to improve on it or how best we can introduce it into the market.
[00:19:10] But since then and since we got a lot of positive outlooks and also other sort
of constructive criticism that helped us build our case even better. Now we have a holistic picture of how it works. So we are just using it as an awareness raising tool. We relocated it from where we had it initially. Now it's set up at our offices. It's a building that I'm currently in. It's an extension of now our office space but still we invite different groups to come and see how the material works and they can even knock on it and see if it's really all over the back.
[00:19:43] And these kind of experiences are the ones that serve to change a lot of
mindsets around timber. It's a tool that we hope would serve to transform the construction industry in Kenya at the moment. So we also targeting the government stakeholders and even today we had a meeting with them and that's where we see the impact coming if we get the government on board and given that they have their own pledges to the national determined contributions in terms of carbon emissions by 2030. This is a project that they would want to be a part of in introducing the carbon footprint of construction and having a country that's really having practices that encourage a net zero approach.
[00:20:22] Adrian Jankowiak: And you've said it as well about people's reactions when they walk into the room. What are some of the feelings that you get from people, the reactions and compared to the concrete building they're used to sitting in?
[00:20:36] George Wekesa: Yeah, I think most people the first reaction they have is more about the smell. So the smell of wood is something that makes people really excited. They're like, wow, it smells really good. And then they start touching it and start knocking on it, as I said before and they get sort of reassured about the structural stability. And then there's the whole like sort of... I would call it a microclimate inside. The fact that it has thermal properties, thermal insulation properties, when it's really hot outside it's cool inside.
[00:21:07] And when it's really cold outside, inside is like moderate temperatures that
are still comfortable. So you just realize this difference as you come in and then I think these are the immediate reactions that we get from people where they're just amazed about the difference they would get with the concrete or steel building.
[00:21:23] But that's not to say that we are only thinking about mass timber as the only
solution for sort of mitigating the climate change. It still has to work hand in hand with concrete and steel. And the reason being is different materials have different strengths and weaknesses. For timber, its biggest weakness is water.
[00:21:43] So you don't want timber to be exposed or to touch water anywhere on the
design. You need to have a planeth that's made out of concrete, which the timber can rest on. And that planeth serves as a sort of water proofing, weather protection that allows the timber to survive on the upper plane.
[00:22:02] There's always a need to emphasize that it's all about material or resource
optimization. You don't just use timber for timber's sake and I don't know how to call it, greenwash the building somehow. You have to carefully understand with your team of consultants, your structure engineers, where is timber the most suitable material in this building?
[00:22:23] And it can end up that you have a hybrid building that's made up of different
elements, but the fact that you use timber strategically, still significantly lowers the overall carbon footprint of the building.
[00:22:36] Adrian Jankowiak: Nice. Great. Have you got any other insights you'd like to share? Any of the challenges that you guys have been going through besides being able to source the wood? What's it like to work with, right. With some experiences of what it's like to put up a building using a combined method either hybrid of mass timber and something else compared to just a concrete structure or brick structure?
[00:23:00] George Wekesa: We've had some challenges before and I think this is with any new material you're trying to introduce. There's always pushback that you have to spend a lot of time sort of raising awareness. I think the key challenge has been around the perception about timber. In Kenya, we have a logging ban which doesn't allow you to harvest or harvest timber to a certain threshold for commercial purposes. And this has led timber to be kind of vilified. Like this is a thing that you shouldn't do, you know, so everyone is like scared, like, why are you doing that? It's the thing that we're told not to do.
[00:23:38] But at the same time, they put this logging ban in place because we were losing our forest at a very rapid pace. The little area that we can keep green, we should keep it as green as possible, and we were losing much of that.
[00:23:52] So the logging ban was to help with improving our forest potential. But there haven't been measures that have been put in place to ensure that the forestry
cover thrives a lot. And this is why with us coming in with this sort of building product that incentivizes a lot of forestry growth, it's something that's much needed to drive forestry growth in Kenya.
[00:24:10] So just talking about misconceptions. These misconceptions around termites. The product is actually treated- it's called a pressure impregnation treatment
system that allows it not to be affected by termites and there different ways it can also design the building to avoid having those crevices and nooks where termites can access the wood.
[00:24:30] So there also other design measures you can take into account. The other one is around policy. The current Kenya building codes, they don't really expressly
say don't use wood. They're just not very clear about the direction we should take. But there's a new draft of the national building code, the 2022 National Building Code that's pending to be gazetted by the Parliament.
[00:24:53] This building code is good enough that it provides a legal framework for us to link it to other established European building codes that allow the use of timber for structural reasons and for high rise buildings. These are the kind of changes we would want to see. And also changes like lifting the login moratorium or the logging ban.
[00:25:13] But also changes in the building industry where we need a very encouraging
building code that allows this building material to thrive.
[00:25:21] Adrian Jankowiak: Great. What's coming next for this project? What should people look out for and where should they find it?
[00:25:28] George Wekesa: Yes. So we are excited to launch our next building. I've been hinting at it a lot. We have designed a flagship commercial office building which will be located in a prime location here in Nairobi. It's a building that has had a lot of input into it. We did like a future of work research to understand better how to provide office spaces that are more forward thinking. We're also using timber, which will significantly lower the carbon footprint of the building, and beyond that we are also adding other measures that allow us to get the highest level of green certification in the market. So this building will be really exciting. It'll have a lot of features that would be inviting for the public as well to come and visit. We see it as one that would serve as a landmark that would inspire the change that we want to see.
[00:26:15] Adrian Jankowiak: Sounds really exciting. Any expected dates for that?
[00:26:19] George Wekesa: Um, so I think we'll have it in stages. So we'll have like a preliminary sort of launch, which I think would be toward the end of this year around October just showing what we've been working on- the design, the concept, the technical information that bugs it.
[00:26:37] Then beyond that, we'll be doing the other lounge where it's like groundbreaking. So that will be sometime either end of next year or beginning of 2025.
[00:26:46] Adrian Jankowiak: Great. Well, thank you Wekesa. Have you got any questions you'd like to ask or anything you'd like to put forward to the audience?
[00:26:53] George Wekesa: I think it's just a reminder that with change always comes a little friction from, from different people. And this is something that we are trying to pioneer and we are facing a lot of challenges in that process. But I think the encouraging thing is most design professionals be it furniture designers, architects, structure engineers and the like have really the knack to support it. So they're the people we are seeing as our ambassadors in this. And the more and more of you or all of you getting to understand the potential, the full potential of using mass timber in
construction. The more you'd be able to sort of advocate for us even on a wider scale.
[00:27:35] Also just something to inspire you. I think when concrete and steel come into the market in African cities there had already been a lot of developments with it in other parts of the world. So there were a lot of precedents of building technologies that have really biased the way we've uptaken concrete and steel in the use of our buildings. Cause we tend to look at what examples are there in Europe or North America. But at the same time, Mass Timber has only been in the market for about 30 years now, so we are at a point where we can reinvent how we form our own local precedents because it's a material that doesn't have a whole lot of exploration done out there.
[00:28:19] People in the US are still grappling with it. I was there recently at an
international mass timber conference. And I realized that it's actually we're facing the same challenges of like perceptions and people not wanting to use it. So it sort of levels the playing field and makes us starts thinking from scratch.
[00:28:37] So we are not overly biased. And this question of like, do we have an
architectural identity that's like African, all that are things that can now start being addressed because this is a material that is at the very early stages and so almost everyone is still grappling with it. So we can find our way through this sort of confusion and come up with our own identity.
[00:28:58] And I think we should strive to do that cause that's how I think we can
reinforce certain cultural beliefs and certain identities that we feel might have been eroded with different inferences that have come before this time.
[00:29:14] Adrian Jankowiak: Yeah, I really like what you said there. There's often you see buildings in places that clearly weren't designed for that place. It was just a copy and paste job and hopefully it will not just be on the, on the biggest scale in terms of the way the buildings are shaped, but also the way that they're designed inside for particular cultural practices for particular things that people enjoy doing in particular places in the world.
[00:29:41] Right? That's a really exciting prospect.
[00:29:44] George Wekesa: Yeah. It's truly something that can revolutionize how we contextualize solutions. So we would have to think about the appropriate solutions for our context, and then this would form the precedence of whatever comes after that. And that will really be a very good way to approach this.
[00:30:02] Adrian Jankowiak: Great. Well this has been really informative. I hope people have learned something and I hope really, really sincerely hope we get to see the more prototype buildings, more test runs and get to see this one that you were referring to as well soon. So keep us updated with it and we'll look forward.
[00:30:22] Thank you.
[00:30:23] George Wekesa: Yeah. Thank you so much.