We’ve been building for a long time and the materials used haven’t changed significantly. The Romans used concrete, the first iron bridge was opened in 1781 and the modern steel making process really kicked off in 1856.
However, we’ve reached a tipping point with the use of these materials. Concrete is one of the most widely used man-made materials, but it comes with a price. Studies show cement is the source of about 8% of the world’s carbon dioxide emissions – if the industry were a country, it would be the third largest emitter in the world.
Our approach to building design has a significant role to play in addressing this. We need to design buildings which meet the needs of the increasing population, reduce emissions and are adaptable to the changing climate.
So, how do we drive these changes?
At the design phase, we work with ever more powerful computing hardware and software. This allows true 3D design, parametric and automated design, and interrogation of the phasing of construction. Using these tools allows teams to focus on optimising design, and the design for construction, making buildings easier, quicker and cheaper to build.
Recent developments in material technology allow us to design buildings that are lighter, stronger and more resilient, while having a smaller environmental impact.
While reinforced concrete is an excellent building material, its production is one of the largest contributors to the global CO2. The onus is on us to actively reduce the amount of concrete in a building.
Perhaps most exciting for New Zealand is the development of wood-based products; we’re seeing engineered timber used in new and innovative ways.
First came plywood, then Cross Laminated Timber, which is composed of different layers of sawn timber glued together. There’s also Brettstapel, where layers of timber are fixed with timber dowels.
New processes allow exotic materials such as Superwood to be manufactured. Superwood is a fascinating development; by soaking wood in a mix of chemicals, compressing and heating it, a material is created which is claimed to be stronger than steel.
Innovations like this allow a step change in construction technology. New, light weight materials such as carbon fibre are already being used to strengthen buildings and alternative uses of carbon, such as graphene or carbon nanotubes, will significantly improve building performance. It is possible that we may yet see these materials used as surface skins for the interiors and exteriors of buildings due to their ability to respond to the environment.
Another emerging trend is the 3D printing of walls. Flowable and quick-setting, these materials allow integration of structural, thermal and acoustic properties. Chemical engineering of these materials will ultimately produce an alternative material to cement. Looking even further into the future, biomimicry and the development of genetic engineering could allow corals,
or similar animals, to grow in a matter of hours to produce building materials.
Buildings should make a positive difference to the environment. We need to design in a way that requires less energy during construction, and for buildings to use low energy, even generate their own power to become truly carbon negative.
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