Whole life carbon

Achieving ‘carbon neutrality’ in the built environment is the stated goal of current government policy and regulatory measures. Part L of the Building Regulations, Town Planning requirements, as well as sustainability rating schemes such as BREEAM, LEED etc. all focus on reducing operational carbon emissions. Currently, carbon embodied in the building fabric during construction and subsequent maintenance is not addressed, though it now comprises a larger proportion of the total carbon footprint of new buildings (RICS Whole Life Carbon Assessment for the Built Environment, 1st edition 2017).

Whole life embodied carbon emissions (as a percentage of the total) currently account for 67% of new offices and 69% of residential buildings. This share of the total will increase as further energy saving measures and more efficient technologies are introduced.

Therefore, it is increasingly necessary to assess the whole life carbon impact of construction in order to reach a genuinely carbon neutral outcome.

We target both operational net carbon neutral and negative embodied carbon, making efficient use of biogenic materials and circular design principles. Whole life carbon assessment is integral to all stages of the design, fabrication and assembly of the system as well as future maintenance and alterations.

Carbon Negative

Or should that be positive?

A growing number of corporations and other organisations define their strategic objectives using these apparently contradictory terms. In 2015 Unilever, for example, made a commitment to be carbon positive by 2030. Microsoft is committed to become carbon negative by 2030. They both mean the same thing. Who’s right?

When we say ‘carbon negative’ we mean that the net effect of our materials, processes and design choices will be to remove more carbon dioxide from the atmosphere than they contribute.

Design and material choices fall within a spectrum, ranging from very high embodied carbon options, such as those derived from the petrochemical industry, to materials such as hemp shiv and wood which capture more carbon dioxide than is produced by harvest and processing. It seems logical therefore to call these natural materials carbon negative.

However, our overriding objective is to find affordable and durable construction solutions, so a high embodied carbon material such as steel might be justified if designed for disassembly, re-use or re-cycling. And when balanced against other materials that sequester carbon emissions, the net result can still be a total carbon footprint which is not only greatly reduced, but negative.