What’s new in Whole Life Carbon assessment guidance?

Whole Life-Cycle Carbon (WLC) emissions are the embodied carbon emissions resulting from the materials, construction, and the use of a building over its entire life, including its demolition and disposal.

The Great London Authority (GLA) has now published the final versions of the guidance for Whole Life-Cycle Carbon assessment after extensive consultation with industry and stakeholders. In accordance with London Plan Policy, the guidance requires developers to fully consider the lowest carbon options which include retaining existing buildings as much as possible before substantial demolition is proposed.

A WLC assessment requires applicants to show how they have calculated and reduced the carbon emissions of their proposal and encourages the retention and reuse of existing materials and structures to promote sustainable building practices.

Applications for developments referred to the Mayor of London, i.e. those subject to an Environment Impact Assessment (EIA), also require a WLC statement to be submitted at the following stages:

• Pre-application (where relevant)
• Planning application submission (i.e RIBA stage 2/3)
• Post-construction (i.e prior to the development being occupied)

The carbon benefits of demolition and new build are proving more and more difficult to measure as a high proportion of lifetime carbon emissions are associated with embodied carbon. The emissions associated with demolition work as well as new construction now have to be included in applications and if actual figures are not available or if it is difficult to estimate the emissions from demolition activities, applicants can apply a standard assumption as mentioned in the new guidance to the gross internal area (GIA) of the existing areas being demolished that fall within the boundary line.

The new guidance has also advised practical solutions of how to reduce carbon emissions. Some examples are below:

• Retaining existing built structures for reuse and retrofit, where possible
• Use repurposed or recycled materials
• Appropriate low-carbon material choices e.g. reused or recycled materials and products, plus products made from renewable sources
• Minimise operational energy and water use
• Disassembly and reuse e.g using lime rather than cement mortar – the former being removable at the end of a building’s life, the latter not.

The GLA has also devised a WLC assessment template to make it easy to report and will also provide consistency. The guidance has confirmed that local authorities should secure post-construction WLC assessments by a condition or through a legal agreement with the planning applicant.

Temple’s Climate and Carbon team is experienced in the preparation of Whole Life Carbon Assessment, and our consultants are well placed to offer advice on how to achieve net-zero for a development.