GLA publishes final Whole Life Carbon and Circular Economy guidance

By: Aspa Skorletou and Dave Cheshire

The GLA’s ground-breaking whole life carbon and circular economy policies are already having an impact, with major schemes being routinely challenged on their upfront carbon impacts.

The GLA has now published the final versions of the guidance for Whole Life Carbon Assessments and Circular Economy Statements, after extensive consultation with industry. The revised guidance is emphasising the importance of refurbishment over new build and applicants now have to demonstrate that the benefits of demolition outweigh the benefits of retrofit.

The carbon benefits of demolition and new build are proving more and more difficult to demonstrate as a high proportion of lifetime carbon emissions are associated with embodied carbon, as shown in Figure 1. Applicants now have to calculate the emissions associated with demolition works as well as the new construction, and if figures for demolition are not known, a new 50kgCO2e/m2 embodied carbon allowance will be applied for the demolition of a building.

Figure 1: illustrative whole life CO2 emissions on new build versus refurbishment

Any project that is close to the embodied carbon benchmarks set by the GLA would be tipped over the limit by this new demolition allowance. Most of the easy-wins in new buildings, such a cement substitutes, low carbon steel and use of materials with a high recycled content will provide, at most, a 200kgCO2e/m2 reduction in embodied carbon so a quarter of these savings would be wiped out by the new demolition figure.

The final version of the Circular Economy Statement guidance is also prioritising retention, refurbishment and deconstruction over demolition, with a new decision tree that includes a hierarchy and additional guidance on pre-refurbishment / pre-demolition audits (Figure 2).

Figure 2: Decision tree for design approaches for existing structures/buildings (from GLA guidance)

The GLA now has over a year of data from Circular Economy Statements that have been submitted and is publishing these figures to provide applicants with guidance on good and best practice performance (summarised in Figure 3). It is also asking for more information at the Outline Application stage to drive decision-making at those early, influential changes.

Figure 3: Median, upper and lower quartile figures from applications (summarised from GLA guidance)

Reducing embodied carbon emissions and moving to a more circular economy is essential for meeting net zero targets and tackling the climate crisis. This newly published guidance is another major step in the move to implement this on major projects in London.?