Challenge
How can housebuilders encourage carbon reductions across the construction industry?
The buildings we live and work in account for 40% of global emissions each year. And while the construction industry already focuses on creating more energy-efficient homes, reducing the built environment’s carbon footprint starts from the ground up: with the construction of homes. A significant amount of the industry’s emissions – 11% – comes from the carbon emissions embedded within the building itself. Yet, steel, cement, concrete and other materials the industry relies on are among the hardest to decarbonise.
Wishing to push the industry’s needle, Bellway sought to tackle the embodied emissions of its homes. The developer wanted to measure the impact of its homes not after they were built but beforehand. In doing so, Bellway hoped to liaise with suppliers and identify how procurement decisions can minimise its footprint.
Scope 3 emissions
Indirect emissions (which do not fall under Scope 2 emissions) that can be found across an organisation’s value chain. It covers the emissions generated by suppliers, distributors and consumers, e.g., through the purchase of services and goods, business travel and waste in operations. It also encompasses activities like leased assets, transport and distribution, the use and disposal of sold products and the impact of any investments. The Greenhouse Gas Protocol’s Scope 3 Standard has identified 15 categories across upstream and downstream activities.
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Integrating the life cycle emissions of a standard house into Bellway’s wider carbon footprint
Housebuilders manufacture a single product: a building. As such, they are in the unique position to integrate the emissions of their product’s life cycle, and thereby the embodied carbon of their homes, into their wider organisational footprint. In recognition of this, Bellway developed a calculation model with which it could measure the carbon impact of its homes and its different components.
However, it first wanted to ensure this method and model would give accurate footprint measurements. Having worked with Bellway since 2015, the Carbon Trust:
Advised Bellway on its emissions calculation tool and how the company can first improve the accuracy of its model before verifying the carbon figures.
Calculated and verified Bellway’s emissions baseline so it can accurately measure progress. This confirmed that purchased goods and the use of Bellway’s houses fuel the company’s carbon footprint.
Identified a carbon reduction pathway for Bellway in line with the latest climate science. In tandem, we completed a gap analysis to understand how Bellway’s value chain emissions need to reduce. This saw us analyse the impact that the UK’s ‘Future Homes Standard’ and Bellway’s supplier engagement strategy would have on its Scope 3 emissions.
Enabled Bellway to set near-term science-based carbon reduction targets* which have been validated by the Science Based Targets initiative.
Bellway commits to reduce its Scope 3 emissions by 55% per m2 of completed floor area by 2030.
* Bellway's science-based targets for reducing its Scope 1 and 2 emissions are in line with a 1.5C trajectory. Its Scope 3 carbon reduction goal aligns to a well below 2C pathway.
Impact
Enabling low carbon design and procurement choices
In 2022 the Science Based Targets initiative validated Bellway’s short-term carbon reduction targets for its Scope 1, 2 and 3 emissions.
By integrating the life cycle assessment of a standard Bellway home into Bellway’s wider footprint, the housebuilder obtains a bottom-up view of its carbon impact. This approach helps the building provider to break down the emissions of the different parts of its homes and consider ways to reduce emissions before a house is built. In doing so, Bellway is able to:
Understand the opportunities at hand to tackle its embodied carbon emissions as the new footprint breaks down the fabric of the house by emissions. This will help Bellway redesign homes for more efficient use of materials and swap high carbon materials with low carbon substitutions.
Use the model in a dedicated testing facility, ‘The Future Home’ which is part of the Energy House 2.0 Project. From 2023, Bellway has been testing different building materials and green technologies for the design and construction of new homes in temperatures as high as 40C and low as -20C.
Futureproof its design specification. In doing so, Bellway can mitigate the risk of future carbon taxes while credibly communicating an energy-efficient, low carbon design to its customers.
Be in a much more informed position to engage with suppliers, factoring carbon intensity into procurement decisions and discuss low carbon solutions with suppliers.
Another form of carbon footprinting for the built environment
Integrating the life cycle assessments of a standard home into a building provider’s value chain footprint can help housebuilders improve the accuracy of their carbon footprints. Housebuilders receive a much clearer picture of the emission hotspots within their products as they move away from using spend-based data.
Instead, they shift towards a quantity-based approach and disaggregate the different parts of the homes they plan to develop. In doing so, builders can design low carbon homes and make more sustainable supplier, material and design choices from the get-go.
For construction companies, this breakdown of emissions sets the scene for more targeted conversations with suppliers. After all, shifting a product mix toward less carbon intense products will encourage material suppliers to tackle their own carbon footprint.
Sustainability is at the heart of our business. Through our ‘Better with Bellway’ strategy we aim to create new and sustainable communities, putting people and the planet first. One of our strategic priorities is to reduce the carbon impact of our business and of the homes we build. We began working with the Carbon Trust several years ago to map our Scope 3 impacts as part of our strategy to set stretching and measurable science-based targets. The Carbon Trust’s assistance and expertise has been invaluable in guiding our work on Scope 3 emissions and target setting.
