Delivering Net Zero – An evidence base

An options appraisal of carbon metrics for new Local Plans in London

The Delivering Net Zero study provides an evidence base to support emerging planning policies for 18 London boroughs seeking to deliver net zero carbon development. The study reviews two policy option routes and provides Pros and Cons, tests example schemes and calculates expected impact.

Policy Option 1 – using the Part L framework and Part L modelling

which operates within the framework of Part L 2021, continuing the current practice of focusing on reducing regulated carbon emissions by a certain percentage. This option emphasises a single metric: the percentage reduction in carbon emissions compared to the baseline set by Part L 2021. It allows for carbon offsetting to play a significant role in achieving Net Zero status, it does not address emissions from equipment and appliances (unregulated emissions) and relies on energy modelling that does not predict actual energy use.

Policy Option 2 – using energy-based metrics and predictive energy modelling

which proposes a more comprehensive approach by incorporating a suite of energy-based metrics. This option focuses on achieving absolute energy use targets, banning the use of gas boilers in new buildings, and utilising predictive energy modelling to ensure that buildings meet Net Zero Carbon standards in operation. It considers all energy uses within a building and seeks to balance energy consumption with on-site renewable energy generation. Policy Option 2 is based on measurable outcomes during operation rather than theoretical reductions.

Comprehensive energy and cost modelling was undertaken on four domestic typologies (terrace house, low-rise, mid-rise, high-rise apartment blocks) and four non-domestic typologies (office, industrial, school and hotel) across 24 different fabric and system scenarios. 

The main report, together with an executive summary and a 20 minute summary version are available to download from Haringey and Merton Councils websites and supersede the Towards Net Zero Carbon report published in 2020. They seek to provide planning officers with the evidence required to demonstrate that the targets set are technically achievable and enabler hem to understand their (limited) impact on capital cost.

This work is the result of a significant and very positive collaboration effort between the 18 London boroughs and the multi-disciplinary consultant team (Levitt Bernstein, Inkling, Introba, Currie and Brown and Etude).

Thank you to Haringey Council for leading the study, and to all the other boroughs: Barking & Dagenham / Be First, Barnet, Camden, Ealing, Enfield, Greenwich, Hackney, Harrow, Havering, Hounslow, Kensington and Chelsea, Merton, Sutton, Tower Hamlets, Waltham Forest, Wandsworth and Westminster. The regular workshops and discussions between you and our team have been very collaborative and significantly contributed to the quality of the evidence base.

For further information on the study please contact Thomas Lefevre (thomas.lefevre@etude.co.uk).