The Government’s target of building 300,000 new homes per year means that a huge amount of construction is anticipated over the coming decade. Although the operating energy efficiency of a building is taken into account, the embodied carbon cost of the construction is not required by current policy to be assessed or controlled, other than on a voluntary basis.
A recent change to permitted development rights provides that “builders will no longer need a normal planning application to demolish and rebuild vacant and redundant residential and commercial buildings if they are rebuilt as homes”. provided that the building was constructed before 1990. While this is designed to stimulate housing delivery, there are questions about whether demolition and rebuilding is the most sustainable approach from a life-cycle carbon standpoint.
The Future Homes Standard will come into effect in England in 2025 and ensure that new homes are futureproofed with low-carbon heating systems and high levels of energy efficiency. Demand for cooling is also likely to increase in future and buildings which can cool themselves passively will reduce the demand on the grid. Setting clear guidelines for sustainable construction now will ensure that we do not lock in a high carbon approach to building new homes and other structures, making it harder to achieve the UK’s net zero target.
Where new building is necessary, the construction industry is well placed to establish a market for low-carbon building materials, but there is no incentive to move away from concrete and steel as the primary structural materials in new builds. Lower-carbon building can be achieved through a number of routes, from using low-carbon resources like wood and other natural materials, to ensuring that building design utilises the minimum amount of resources.
Green infrastructure can provide numerous benefits to complement the built environment such as cooling urban areas in heatwaves, creating networks of habitats, reducing run-off and flooding, providing job creation and improving people’s health and wellbeing.
The Climate Change Committee’s 2019 Report, UK Housing Fit for the Future makes a number of recommendations to Government on sustainable building, including incentivising the increased use of wood in construction and developing policies to minimise the whole life carbon impact of new buildings. This inquiry aims to follow up on the progress of these recommendations.
Embodied carbon will play a much more significant role in the heat decarbonisation debate as we reap the benefits of grid decarbonisation. Carbon emitted in the manufacture, transport, and construction of building materials and the assessment of whole life carbon is not currently within remit of the Building Regulations and we would urge government to consider how tighter fabric and energy efficiency standards – alongside changes to the planning system – can be used to drive the increased use of alternative construction methods for more sustainable housing in line with net zero.
Energy Systems Catapult’s Six Steps to Zero Carbon Buildings identifies the key policy levers to develop a mix of new planning processes, standards, obligations, subsidies and market incentives to drive action and restructuring throughout the supply chain.
We would also encourage proposals to help develop policies to minimise the whole life carbon impacts of the UK’s buildings, incorporating LAEP into the spatial planning picture, and creating a mix of incentives, standards and obligations to address building decarbonisation.
The interim standard proposed in the government’s response to the Future Homes Standard can act as an important catalyst for building the necessary skills and supply chain required for net zero, as the UK does not currently have either the quantity or quality of skills required to meet the government’s net zero targets.
Improved arrangements for monitoring, reporting and verification (MRV) of carbon emissions throughout value chains can also play a key role in driving the use of more sustainable materials in the built environment.
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Environmental Audit Committee – Sustainability of the built environment