Considering Embodied Carbon

Usually when we think about a sustainable home, we most often consider our energy usage - appliances, and predominantly heating & cooling - and aim to create the most energy-efficient building possible, with the understanding that less power consumption = less fossil fuel usage = less CO2. This is of course a vital aspect of design, but the impact of the materials of the building, and the process of construction, is equally as important - and often overlooked.

Every building product has a carbon footprint. This is made up of the emissions created in the extraction of raw materials, the manufacture of the product, the running costs of factories, the transport from factory to supplier, and so on. This figure is known as the Embodied Carbon of a material.

And of course, some materials have much higher embodied carbon than others - for example, a timber-framed house has embodied carbon up to 3 times lower than the same house in brick. And concrete alone accounts for up to 8% of all global emissions!

So how do we design out excessive embodied carbon?

Choosing more sustainable materials - Timber framing, cellulose insulation, straw bales are some examples of organic materials that require comparatively less processing - Straw bales are actually a waste product from existing farming processes. Additionally, some suppliers of heavily processed materials like aluminium are starting to offer a no- or low-carbon alternative for standard products.

Recycled material - Glass and Aluminium both can be recycled and re-formed indefinitely, reducing the CO2 emissions of the raw material extraction process. The same is true for steel frames, masonry, etc. The last decade has seen a whole host of new materials composed entirely from existing waste products.

Choosing local - Where possible, selecting locally made products is a smart way to remove the carbon price tag of transport of goods - some imported materials pass through up to 5 different countries before the reach a building site.

Efficient design - As much as is practical, it helps to design homes with less material wastage - simpler detailing, less complex assemblies & geometry mean less offcuts & less waste.

With enough careful design consideration, we can keep as small a carbon footprint as possible when building - and throughout the life of the building.

Get in touch today to learn more about designing your low-carbon home.