WHAT DOES IT MEAN FOR YOUR PROJECT?

Over the past 30 years, progressive iterations of the Building Regulations have focused on reducing household energy consumption and carbon emissions in use. But with modern homes reaching excellent levels of efficiency, we all need to think more about the energy that goes into actually building them, says Nigel Griffiths

We’re getting better and better at constructing buildings which have low energy demand when in use (operational energy). As we do, the importance of the embodied energy emitted during their construction becomes relatively more important to a project’s sustainability credentials. So, in this article I’m going to explore what embodied energy and carbon are, why they matter, how they’re measured and what we can do to minimise these aspects of the environmental impact of our new buildings.

What is embodied energy?

Put simply, this refers to the energy used in the production, transportation and installation of building materials. The term embodied carbon translates this into carbon dioxide (CO2), the most common greenhouse gas. Different fuels have different CO2 components, so a building material that’s largely manufactured using electricity will have a different carbon footprint (per unit of energy) to one produced using coal or gas. Where an industrial process emits other greenhouses gases –methane (CH4), nitrous oxide (N2O) etc – these are converted into their carbon dioxide equivalent, identified as CO2e.

As the efficiency of new buildings increases, the impact of construction, maintenance and demolition becomes relatively larger compared to the operational energy of the in-use phase

Determined to use renewable materials wherever possible in her self build, Kim Siu opted for a timber frame structure, straw bale insulation and locally grown larch cladding. Not only was this a sustainable approach but it also helped make the new home blend into its surroundings. The prefabricated timber panels were craned into place with the straw sealed inside

NIGEL RIGDEN