What’s so special about bamboo? Why should a UK practice choose to build in engineered bamboo as opposed to, say, CLT?

David Trujillo It makes more sense to ask why somebody would choose laminated bamboo over glulam rather than CLT, because we are not yet looking at panels, we’re looking at beams. Some laminated bamboo products perform better than LVL (laminated veneer lumber), which is a superior product to glulam.

We are keen to see the industry flourish because it creates a supply chain that helps many people. The capital investment required to plant and harvest bamboo is small compared to trees, and tiny compared to steel and concrete. The life cycle of bamboo is even better than timber because it grows so quickly. It takes 7-10 years to establish a plantation and then every year after that you can have a harvest. In a mature plantation three- to five-year-old stems are ready to be harvested. It would take you 40 years at least to be able to achieve the same with timber.

Another thing about bamboo is that it’s a grass. Harvesting bamboo is like mowing the lawn. You chop off some of the stems and they grow back. When you chop down trees you have to plant them all over again. And then, what’s really interesting is that, because it can be continuously harvested, you have the potential to build a permanent workforce that is linked to bamboo. With trees you might have a harvest every 40 years. So you assemble a workforce, but it is transient.

Chris Matthews There’s a man called Arief Rabik, who has founded the 1,000 Bamboo Villages project in Indonesia, which is establishing 1,000 village-scale bamboo plantations on degraded land – one really good thing about bamboo is that it has the potential to restore degraded soil – and each plantation is the basis for a community based on growing, harvesting and processing bamboo; the socio-economic potential is huge.

David Trujillo If you think about locations such as Indonesia, or any country in the Global South, it’s a very precarious living, and the idea that you can plan 40 years ahead… it’s not going to happen. But when you look at a crop that takes seven years to grow, and when you can start to see how the benefits might trickle down the supply chain ­– in simplistic terms specifying sustainably sourced bamboo is equivalent to buying Fairtrade coffee, in that it’s a decision that benefits rural farmers in developing countries.

So why aren’t we building in bamboo in the UK?

Chris Matthews We are looking at using bamboo for projects in the UK. There is no reason why you can’t get approval for a bamboo building in the UK. There are two routes to getting through building control. One is a one-off building approval, which looks at the overall performance of the building as a whole. So as long as we can provide testing to the required standards we can get a building approved as a standalone case. But you have to do a large amount of testing when you’re dealing with any material that comes with natural variation and for which there are few precedents.

The other route is that laminated or engineered bamboo gets approved by UKAS (the United Kingdom Accreditation Service) as a standard building material. In principle, it’s much more straightforward to regulate for engineered or laminated bamboo that has been turned into a standardised laminated product.

David Trujillo In the UK we do already have four ISO Standards for bamboo, two for testing and another for grading of the material. I’ve recently been involved in the revision of ISO 22156, the fourth Standard, which focuses on structural design. I have found one of the delights of working with bamboo is that it has forced me to become a better engineer, because you sit down and ask yourself “Why is it we do this in another material?” and “Why did the engineers who came up with these codes come up with what they wrote?” Every question forces you back to first principles. For me it’s been hugely educational.

David, what made you take the job of Head of Bio-Based Materials at Atelier One?

For a long time it has been my dream to spend every hour of the working day working with bamboo. I started my career in Columbia designing bamboo structures. One thing I’ve always liked about bamboo is that it’s a strong material. In certain respects, it’s stronger than most species of timber. In others, less so, but understanding these property differences makes bamboo a complementary material to timber. It’s a beautiful material, and because it’s light and strong you can use it, for instance, for earthquake resistant structures.

When I saw that here, in the UK, there was a company that was taking bamboo seriously and I just thought ‘it doesn’t make sense that we’re in the same country and we’re not collaborating’. For some time Neil and I had already been talking, and we decided to take it one step further. There’s a body of knowledge I’ve accumulated over the years which feeds into the designs.

Does Colombia have an established tradition of using bamboo as a construction material?

David Trujillo In the 1990s and early 2000s the Colombian architect, Simón Vélez, was a trailblazer in terms of what you can do with bamboo. He created some wonderful buildings. Those of us who were at university in that sort of period were inspired. So in the world of bamboo you keep seeing Colombians pop up everywhere. So it’s very convenient that we now have a team, headed up by Luis Fernandez De Canon, based in Colombia where there is a new generation of engineers coming though who have been inspired.

Chris Matthews Luis worked for Atelier One in London for ten years. He went back to Bogotá eight years ago and we have continued to work together ever since. We are building up a team as we are starting to do more work in the region, including the Green School in Tulum, Mexico. The team in Colombia is currently four strong and likely to grow, as we take on more projects in South America and Mexico.

Are you using bamboo in Britain?

Chris Matthews One of our clients, Imagineer Productions, an art/science/engineering creative organisation based in Coventry, did a theatrical piece based around a timber bridge in Dagenham. They phoned us up and said “what can we do next?”  A series of talks and Zoom workshops during Lockdown culminated in a three-day festival in Birmingham last summer, which was basically about artists, designers, engineers and communities working out how to use bamboo. We had people from Bali, including John Hardy. We had Jed Long, a bamboo expert from Australia. We had the NoFit State Circus troupe. We’d been discussing what structure to build to demonstrate that it isn’t just for garden cane. We made a 14-metre arch all from bamboo grown in the UK, built by volunteers, and we had people swinging off it. I’ve got to admit the first version of it was a little flexible, but we made another version of it later at Keele University, with improved joints, which was wonderful, and able to support a trapeze artist.

So when do you envisage you’ll deliver your first bamboo building here in the UK?

Chris Matthews We’ve introduced bamboo structures a few times in competition entries, but none of them have gone any further. There is a lot of interest, and interest is growing all the time from both architects and developers. There is currently a potential project for some eco lodges, but it’s early days yet.

A large developer commissioned us to do some work replacing existing steel and concrete structures. They asked us how we could incorporate more biobased materials within a standard office building without altering the other elements of the building. We came up with a series of criteria you’d have to fulfil – vibrations, thermal comfort, services, embodied carbon, fire performance, load capacity etc ­– and worked out that, if you were to make a folded plate, you could meet all the criteria with a timber or bamboo floor in the same structural zone as you could with a steel or concrete floor. Since a lot of embodied carbon is in the floor slab, the carbon saving you could make is huge. There’s a certain lack of flexibility in the timeline where you say OK, let’s have a steel or concrete deck, because you can just slot an existing solution in without having to develop the concept further. It’s just about having thinking about what is appropriate early on and being ready to do the work at the right time.