The UK Green Building Council (UKGBC) has published a study showing how housing developers can achieve a 20% embodied carbon reduction on low-rise residential developments through some simple and cost-effective masterplan-level design interventions
It is well known that the government has made commitments to achieve net zero by 2050. It also has ambitious plans to build 300,000 new homes a year by the mid-2020s.
However, existing housing is already contributing to 16% of the UK’s greenhouse gas emissions and so the housing development sector must institute some serious changes to make these net zero ambitions a reality.
The latest report from UKGBC, titled ‘Building the Case for Net Zero: A case study for low carbon residential developments’, examines how embodied carbon can be reduced in a real-world situation by testing the design and cost implications on a low-rise residential scheme in Southwest Cambridgeshire.
The UKGBC also provides insight on how related masterplan elements, such as roads, utilities and energy infrastructure, must be considered in the transition to net zero. This is something that many developers overlook.
The study’s key findings:
Overall, a 20.3% embodied carbon reduction was achieved between the ‘baseline’ and ‘stretch’ design scenarios, with a negligible impact on capital costs (0.6% increase). [1]
It suggests some practical interventions for embodied carbon reduction such as minimising a parking area to embrace the shift towards vehicle sharing and the use of swales to reduce stormwater drainage.
Culturally, people must change their attitude away from car ownership and towards public transport and walking and cycling. This will reduce embodied carbon from both grey infrastructure and transport emissions. All residential developers must consider the future of sustainable travel.
The report stipulates that masterplanning can feature simple nature-based solutions to enhance the resilience of homes to harsh weather. Solutions may include replacing hard surfaces with soft landscaping and trees, which can reduce embodied carbon and flood risk whilst contributing to increased biodiversity net gain.
New developments can play a vital role in improving residents’ health and wellbeing as well as creating a sense of community through the wider use of communal gardens and access to nature and green spaces.
UKGBC’s Whole Life Carbon Roadmap
This roadmap indicates that the impact of embodied carbon is set to increase and will form over half of built environment emissions by 2035.
In spite of the momentous opportunity to reduce carbon in the built environment, embodied carbon emissions are currently unregulated, with measurement and mitigation within construction typically voluntary.
Despite recent changes to encourage housing developers to consider embodied carbon usage, there needs to be further clarity on how it can be measured and mitigated within the planning system in England to make lasting change.
Overall, the report highlights the important role of planning and masterplanning in delivering a holistic approach to sustainability. It also pledges its support for the government to take ambitious steps to strengthen sustainability requirements through the planning system.
The new resource will be used by local authorities, investors, developers, housebuilders and stakeholders seeking to better understand how to deliver new low carbon residential developments.
At the time of writing, the UK Government prepares the upcoming Planning Bill, and the Scottish Government consults on its National Planning Framework 4 and so the study is relevant to national policymakers.
‘Readily available solutions’
UKGBC’s head of climate action, Yetunde Abdul, said:
“Each tonne of carbon from the built environment must be measured and mitigated in order for the UK’s net zero targets to remain within reach. Embodied carbon from masterplan works is no exception to this, yet it is often an oversight by developers leaving large amounts of carbon unchecked and ill-considered.
“This study provides evidence that considerable amounts of embodied carbon can be slashed through simple design interventions and at little capital cost to developers. Through gaining insight into the impacts of embodied carbon, this study also uncovers opportunities to improve the masterplan holistically, including climate resilience, biodiversity net gain and creating better amenities for residents.”
Pauline Martin, sustainability manager at Lendlease said:
“Critical elements of infrastructure, which contribute a significant portion to a project’s embodied carbon footprint have often been overlooked to date. We welcome this publication from the UKGBC outlining the importance of incorporating low embodied carbon design options at the early master planning phase. Further to this work, we look forward to UKGBC’s forthcoming work specifically focused on the cost of delivering net zero carbon homes.”
Chris Brown, executive chair and founder at igloo Regeneration said:
“Whilst the Future Homes Standard (2025) and grid decarbonisation (2035) will help eliminate operational carbon from new homes, two key challenges remain: embodied carbon and the electricity grid’s capacity to cope with the heat pump and EV charging load.
“Echoing the Home of 2030 winning entries, this report helps developers to deliver lower carbon developments through its focus on the upfront carbon of the masterplan works, suggesting helpful, readily available solutions including landscaped swales, active travel with fewer cars and more efficient roads and parking.”
[1] Excluding infrastructure related to heating, as this has been modelled separately to ensure a like-for-like comparison for the masterplan works.
