One sixth of the world's CO2 emissions arise from producing steel and cement, which are made efficiently, but used inefficiently; particularly in construction. Technical options to reduce material demand in construction already exist, and present exciting new opportunities to reduce future costs, energy and carbon.
Demand for materials in construction today is driven largely by the relatively low cost of materials compared to labour in the UK: it is potentially cheaper to standardise a building design that to design for individual element efficiency. When building designs use only the materials required, in the right place and without excess, then demand for materials and energy is reduced. However, in a detailed study of 23 commercial buildings, we found multistorey steel structures could, on average, be built with half the amount of steel and still meet the Eurocodes. Buildings in the UK could last for at least 100 years, but on average are replaced after 40. If instead we facilitaded adaptability and maintained the value of buildings over 80 years, we could save long-term costs and emmissions by significantly reducing material use. Most construction depends on four key structural materials: steel, concrete, timber and masonry. Material re-use allows the embodied carbon already expended to be valued over a longer time and avoids the need for new material production; however at present such re-use is rarely practised in the UK. The use of natural materials such as wood may leas to reduced embodied emissions.