Is building new the solution to achieving Net Zero?

Warnings issued by the Intergovernmental Panel on Climate Change (IPCC) about the consequences of climate change are no longer warnings, only the most drastic cuts in carbon emissions from now would help prevent an environmental disaster.¹ Yet, the buildings and construction sector is not on track to achieve decarbonisation by 2050 and the gap between the actual climate performance of the sector and the decarbonisation pathway is widening.² Decarbonising the buildings and construction sector is a critical step to delivering emission cuts – so is building new the answer?

If you are reading this article, you most likely occupy, operate, own or administer a structure which owns an existing building(s) which will still be in use in 2050. In fact, eighty per cent (80%) of the buildings in existence today will still be in use in 2050. Much attention is paid to new build performance, but as architectural studies have proven there are significant emissions reductions associated with the renovation of existing buildings compared to the demolition and construction of new buildings.³

When assessing the best way to cut emissions in the building and construction sector, it is essential to think not just about how much carbon we reduce but when those reductions happen. Since greenhouse gases accumulate in the atmosphere and we have limited time to reduce these emissions to stave off the worst impacts of climate change, immediate carbon reductions have more value than reducing carbon at some later date in the future.⁴ This is the challenge when building new - carbon released into the atmosphere from producing and transporting building materials and from the construction process is instant – therefore, reusing an existing building (even if not as energy-efficient as a new build) would emit far less carbon over fifteen (15) years than a new, considerably more energy-efficient building.⁵

The data is clear: reusing and retrofitting existing buildings is vital to achieving significant emissions reduction targets. However, the United Nations Environment Programme was very clear, the buildings and construction sector is not making the deep systemic changes needed to get on the path to decarbonisation.⁶ Why? The Construction Leadership Council⁷ cited continuing changes to the UK government's net zero policy and availability of skills to complete the retrofits as key constraints.

'We believe that clear policy would encourage sustained business investment, increase consumer confidence, enable the skills system to train the workers required to deliver retrofit, and for the supply chains to develop across the UK.'

'The skills issue is a huge challenge. With retrofitting [buildings], if a customer is spending a lot of money to airtight a house but the person delivering the job isn’t delivering the job correctly, the house won’t be airtight.'

The empirical evidence is clear - the question is not should we retrofit but how can we best support the custodians of existing buildings to retrofit. The buildings and construction sector together with central government must develop clear strategies to make building reuse happen more efficiently and at scale. Businesses need to understand the financial implications, and be able to rely on the rules, affecting net zero investment -- and we don’t have a moment longer to waste.

¹ IPCC report 2022.

² UN Environment Programme, 2022 Global Status Report for Buildings and Construction.

³ Architectural studies conducted by the firm Goody Clancy at the Alan and Sherry Leventhal Centre at Boston University.

⁴ The Time Value of Carbon Initiative led by Larry Strain of Siegel and Strain Architects.

⁵ Architectural studies conducted by the firm Goody Clancy at the Alan and Sherry Leventhal Centre at Boston University

⁶ UN Environment Programme, 2022 Global Status Report for Buildings and Construction.
⁷ Construction Leadership Council – written evidence provided to the UK's Independent Review on Net Zero