HOT TOPIC: Carbon assessments crucial for net zero developments
By Deepika Singhal and Chris Cummings
The GLA has published four pre-consultation draft documents that will have an impact on planning applications once the draft London Plan has been ratified, requiring a higher level of whole life carbon impact to be determined at an early stage.
Delving into a draft document that can’t be fully consulted on until after the publication of the new London Plan might seem like jumping the gun a little, but this could affect a number of schemes we are working on where submission of a planning application is still some way off.
The delays to the London Plan mean we can expect a flurry of activity to make up for lost time when it finally arrives, but to make sure we are able to offer the most robust advice then we need to be searching for clues now.
When the London Plan 2019 does come into force, Policy SI2 will require all referable schemes to carry out a Whole Life Carbon Assessment (WLCA) at the outset of the project, with reporting required at pre-application, planning and post-completion stages.
One big advantage would be that this piece of work will form a part of the concept design and hopefully inform the design and material choices through the course of the project rather than appear as an afterthought. Building circularity and recycling and reusing building material will become part of the discussions from the very beginning.
Though this is welcomed, the level of detail and scope of the assessment required at planning and completion stage is the same. Practically, generic national data would be used at the planning stage, which in most cases discounts some of the ‘Use’ stage modules of the WLCA i.e. use, maintenance, repair, and refurbishment.
The guidance condemns the use of the minimum scope of WLCA as recommended in RICS Practical Statement, however, we feel that approach could provide a reasonable scope for planning stage reporting as it mainly includes product related carbon and operational energy use.
The guidance for operational energy use permits using results from either Part L or TM54. This does provide flexibility, and it will always be difficult to decouple policy and compliance, but the industry is clearly moving away from a compliance-based approach to performance-based modelling.
Programmes like Design for Performance, of which we are committed delivery partners, are gaining momentum and it is positive this is recognised in the guidance. The two permitted approaches will also yield significantly different results, with no guidance yet on how that will be considered when assessing submissions.
The guidance does not align with the UKGBC’s Zero Carbon Definition Framework as it suggests that whole-life carbon is not subject to the Mayor’s net zero carbon target. There are mixed messages here as operational emissions are included within the WLCA, indicating it is recognised that the carbon emissions of a development should be looked at in its entirety.
In our opinion WLCA must be included in the delivery of zero carbon developments.
Developing sensible benchmarks in what is still a nascent field of policy is a challenge, however the GLA’s baseline WLC Benchmarks are significantly less ambitious than the best practice targets of LETI or RIBA.
As an industry we should be striving to take giant steps to meet the zero-carbon target by 2030; for this guidance to achieve more than to simply sweep up the tail-end of development more aspirational targets would be required.
We look forward to submitting a formal technical review when the consultation is open to public. There are several aspects such as the inclusion of sequestered carbon, evidence-based feasibility scenarios, RICS modules, elements in-scope which need further clarity; but then that is the whole purpose of consulting with industry, and why we all must use our voices to drive change in this country along our collective path to net zero.
Deepika Singhal is an Associate leading one of the Environmental delivery teams at chapmanbdsp. Christopher Cummings is Technical Director responsible for all aspects of Environmental and Sustainable design.
