Overview
The Department for Levelling Up, Housing and Communities produced the National Model Design Code in 2021 to provide local authorities and developers direction, policies and guidance for successful design of new developments. The RTPI commissioned us to develop a deeper understanding of the specific role that Design Codes can play in successfully achieving net zero carbon emissions and nature recovery outcomes.
SCOPE
The scope of the study involved producing research and two mock design codes for fictional places in England, including a code for an entire district and a code for a large garden village community. The RTPI wanted the team to consider how the design codes could address the climate and ecological emergency so that they can become stronger and more practical frameworks for end-users such as council planning officers, developers and local people.
CITY SCIENCE RESPONSE
City Science led on the Net Zero element of the research and mock code production process, covering all life cycle emission sources such as construction, maintenance, transport, energy use, food consumption, and demolition.
Baseline Process: We led an in-depth literature review to estimate the typical total site-related carbon emissions from new developments. This included consideration of a wide range of academic sources, guidance, building standards and practical examples including from pre-existing Whole Life-Cycle Carbon Assessments for proposed developments. We also engaged with key organisations like the Green Building Council to establish the status of any emerging guidance or exemplar approaches. We used outcomes of our review to estimate typical lifecycle carbon emissions from new developments across all potential sources. Our novel approach considered whole-life cycle carbon, typically associated with embodied carbon, construction, energy consumption and demolition, alongside in-use human behaviour such as emissions from daily transport use, waste and consumption of goods. Our emission assessment informed the baseline assessment of the design codes to identify key challenges and opportunity areas related to meeting decarbonisation targets. This included the production of a series of mock geospatial maps such as existing public transport accessibility levels, ’20-minute communities’ and energy supply networks.
Decarbonisation Design Principles Development: We used the baseline analysis to develop a vision and overarching critical success factors to guide future development across the district and the site-specific context. This included specific decarbonisation-related targets such as ensuring Aall new homes were located within 10-minutes walk of key amenities and that sites should be powered by 100% renewable sources.
We applied this framework to each component of the design codes to develop more detailed decarbonisation design principles across transport, neighbourhood design and energy. This included production of highly visual infographics to support the future masterplanning process.
We participated in a series of workshops to gather feedback from a broad range of groups on the emerging approach, including housing developers, consultancies and local authorities. We used this feedback to refine and finalise the codes, primarily to ensure that they could be practical for implementation.
Outcome
We co-authored the research paper and mock design codes with LDA Design and BSG Ecology, which received widespread industry coverage. As design codes become more widespread and are now a recommendation in the National Planning Policy Framework, local authorities are actively using the research to ensure that decarbonisation principles are embedded throughout the process.
You can download a copy of the research paper and mock design codes here.
