'Build back better’ with sustainable structures

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Housebuilding is central to plans to kickstart the economy, but we need to start rethinking the way we build if ‘build back better’ is to avoid severe environmental damage, says Steve Webb, Director, Webb Yates.

The oldest fired clay bricks date from 4000BC and were found in China. Prior to the firing of bricks people either built with stone or with mud. The ancient builders probably made a very simple calculation. There was mud under their feet so they would build with that. Fired clay brick walls are much stronger than mud brick walls and so cutting a tree down and burning the mud bricks saved a lot of time digging and brick laying. The brick was the foundation, the structure, the waterproofing, the thermal envelope and the aesthetic finish and very durable. An elegant and logical solution to that society’s needs. With a much lower population and only photosynthetic energy available, this was necessarily kept in balance with nature.

We continue to use brick today. Planners like bricks because they champion continuity in the urban context. Architects like bricks because planners accept them and builders will happily build with them. Builders like bricks because they are used to them and they are commonly available. Brickmakers make bricks because there is huge demand for them.

Bricks are therefore ubiquitous in today’s house building programmes, but the initial reason for using bricks at all has become entirely lost in this complex pattern of repetitious supply and demand.

Brick building is slower than frame building and so brick walls have become non-structural elements, burdening the building’s frame rather than holding it up. They now sit on steel shelf angles that have to be cunningly concealed in mastic joints and given plastic cavity trays and weep holes. Solid brick walls are too thermally conductive for a northern climate and so they are split into two thin cavity walls and stuffed with insulation. Now split into two, they are too weak to support even wind loading and so have to be tied together with brick ties (which now have to be fibre glass to avoid thermal bridging), and reinforced with steel wind posts and bed joint reinforcement. Two skins of brick have become too expensive and so the inner skin has been swapped for concrete blocks, which shrink with time while the outer bricks expand. Cement mortar is used, instead of flexible lime, to strengthen the wall, which makes it more brittle and so regular mastic filled vertical movement joints are needed – rendering the bricks unrecyclable because it is difficult to remove cement mortar.

Bricks are heavy, weak, take ages to build, crack all the time, leach salts, are made with coal or gas, look terrible criss-crossed with mastic gaps and are certainly not in balance with nature at all. In fact, brick making is a polluting process and often as carbon intensive as concrete production. Someone commented recently: “the developer flew to Denmark to choose a beautiful coal fired stock brick for their building in London”, which just about says it all.

This is just an exemplification of the way ‘free market’ practices in construction behave. Along with steel and concrete, brick is a damaging, coal era product. After coronavirus, the government has pledged to ‘build back better’, and housebuilding is central to plans to kickstart the economy and address the housing crisis. But if we’re going to go on a massive building spree without doing severe environmental damage, we’d better start rethinking the way we build and stop churning out the same stuff again and again, simply because we can’t see the bigger picture.

I was really honoured and rather surprised to get the Milne Medal. I’m the sixteenth winner. When I look down the list of previous winners, I see a group of people who have built at a much greater scale than I have. I hope the reason I got it was thanks to my long-term push for sustainability in structures.

This article was originally published on The Engineer