(Image of Kew House by Jack Hobhouse)
Tim Lucas MIStructE is the structural engineer behind Kew House, a previous Structural Award winner and one of the shortlisted projects for RIBA’s 2015 House of the Year competition. As the UK Government announces an extra £2.3bn for house development, Tim discusses how we are building now, how structural engineers should contribute to the discussion, and what we can learn from innovative projects like Kew House.
This new housing funding really offers UK engineers and construction firms a chance to think outside the box about how they put buildings together, and how we use materials.
As engineers we need to go back to first principles about the way houses are designed and built. The key is to think about crafting basic materials like steel and plywood into useful structural components in a more accurate and coordinated way. We call this ‘Digital Craftsmanship’ in the office - creating our own, new ‘Lego’ kit of structural building components using digital fabrication and digital design technology.
In this way we produce accurate components that fit well together, transfer loads between parts, and become less reliant on traditional construction products. This is especially relevant with the large volumes being proposed in the UK housing plan.
Most UK housebuilding is currently set up to suit procurement methods, which are mainly about avoiding risk and separating things out into separate sub contracts. From a sustainability perspective this approach is rather wasteful, as it requires large amounts of redundant material, with different layers of building applied on top of another by separate contractors.
So we also need more ‘out of the box’ thinking from the clients and industry - a willingness to take on a little more risk. Engineers and architects can shape buildings to work better as structures - digital design and digital manufacturing make all this possible – we just need the will from clients to try something new and an industry that is up for the challenge.
Architects and engineers
Building is really like an old fashioned car chassis: a couple of beams joining the wheels together, with (non-structural) coachwork (i.e. cladding) placed on top of it. We can learn a lot from the way modern cars are built, where the body shell is the structure - this saves material and gives you more space in the building.
That’s not to say we should think of housebuilding as a production line: there are lots of housing ‘systems’ around, but sometimes they are overly standardised, and look quite blocky as a result. The trick is for architects and engineers to work together more closely from the start of a project, working with the constraints of a particular site, creating a design that fits its surroundings. That we way we create real efficiency, rather than a frame for other stuff to hang off.
Someone described architects recently as the ‘spiritual’ leaders of the design team. Engineers should think of ourselves as the ‘co-spiritual’ leaders with the architect, because we have the ability to really define how the built environment is made, using minimal resources and applying scientific knowledge and technology. We don’t just need to get our specifications out of books and catalogues.
(Kew House under construction, image by Tim Lucas)
I’m thrilled that my home was shortlisted for RIBA’s House of the Year accolade. My wife and I, as clients, took on a lot of risk, but it was all worth it. The house build involved a number of innovations of which we’re very proud.
As an example the walls of Kew House are only 200mm thick, and 160mm of that is insulation – this frees up a lot of space inside. The Corten shell is cladding, waterproofing and structure wrapped into one building element, which was prefabricated and installed in big modules.
We also built a basement under the house for a factory, which produced elements on-site for the internal fit-out – eliminating the need for visits to joinery workshops.
I’m proud to say that the project educated all involved, with established tradesmen working alongside recent architecture graduates; it also saw traditional methodology meet the modern: with digitally fabricated elements finished by hand and vice versa. I certainly learned a lot too.
Hopefully all the shortlisted House of the Year projects can help provoke a discussion about how to build better homes in the UK – it’s a really important subject for us all, and structural engineers need to have a clear voice in the discussion.