Sustainable Building: Old traditions, new technology

Embodied carbon

Sustainable building isn’t just about how eco-friendly a building is once it’s built. All materials have what’s called embodied carbon, which comes from the processes needed to extract or manufacture them, the transportation required and the process of building with them. For example, concrete is a common building material even in green buildings. However, production of cement (the key ingredient in concrete) accounts for 8% of global C02 emissions per year.

Over the typical 60-year lifespan of a building, up to 75% of its total carbon emissions are from embodied carbon rather than from the day-to-day use of the building. However, there are many ways to reduce embodied carbon, such as using more recycled material. 

Operational emissions

The other percentage of a building’s emissions come from its day-to-day use. It’s important to think about how a building will be powered or heated or cooled. One approach is what’s known as a fabric first approach. The Science Museum Group used this technique when building its new collections storage facility. From the very beginning, architects and designers considered how well the materials used to construct the building would perform.

The aim was to make the building as efficient as possible before considering using additional mechanical or electrical systems, such as air conditioning. Humidity is the enemy of many museum objects and therefore humidity control was very important in the new facility. Various measures, such as making the building as airtight as possible and increasing insulation, mean there’s much less need for mechanical temperature and humidity controls than if the fabric of the building hadn’t been carefully considered at the outset.

Once you’ve made the building itself as efficient as possible, you can also minimise the impact it has on the environment by maximising the use of renewable energy. Back in 1979, Democratic President of the USA Jimmy Carter unveiled solar water heaters on the White House roof and argued that ‘solar energy will not pollute our air or water’.

Increasing the use of renewable energy is a key part of achieving a net-zero carbon building. The UK Green Building Council suggest that having a way to generate renewable energy on site is ideal—this could be as small as a solar panel on a roof or as large as a whole solar array, like the one the Science Museum Group installed at the National Collection Centre.

Renewable energy can also come from the National Grid, which is moving towards energy from renewable sources like offshore windfarms. On 26 August 2020, wind power generated its highest share to date of British electricity, hitting a high of 59.9%. Solar power also hit its highest ever share of British electricity at 34% on 30 May 2020.

Sustainable building is not just about making each individual building more efficient and greener. It’s important to also think about the built environment as a whole and how resilient it is. As the climate changes, the risk of extreme weather events is increasing. We need a built environment that can cope with these changes, and the way we currently build is not always great at this. 

Particularly in cities and towns, a lot of land tends to be covered in surfaces like concrete, asphalt and brick, which are impervious—water cannot run through them. That means that heavy rain is more likely to lead to flash flooding, because the rainwater has nowhere to go. But attempts are being made to tackle this problem. The city of Swansea, for example, is planning to double the amount of green space in the city by 2030. This will create more spaces which will absorb water and therefore reduce flooding. Sustainable building strategies like this can also improve the wellbeing of local communities in other ways, by providing more outdoor space to exercise, socialise and experience nature.