Whole-life carbon or upfront carbon plus energy use? What should the new London Plan limits cover?

The Net Zero Carbon Building Standard (NZCBS) gives us the answer. The NZCBS provides limits for upfront carbon, and energy use, but states that it is the intention for the standard to evolve to provide whole-life carbon (WLC) limits when there is sufficient data available. The question is, have we already reached that point?

The existing GLA policy SI2 (which I co-authored in 2021-22) required full WLC reporting but did not provide limits for the same reasons as NZCBS, although policy SI2 does provide benchmarks for guidance. This was several years ago, and much more WLC data is now available. Let’s examine the issues.

To fully optimise both carbon reduction and resource efficiency we need to do two key things: Firstly, we need to consider the structure, the building envelope and the expected energy use together in an integrated, holistic way, and secondly, we need to examine the carbon impacts of all life cycle stages, ie upfront, in use and end of life also in an integrated and holistic way.