While the built environment accounts for 40% of global emissions, efforts to reach net zero remain fragmented. Unintended effects of well-intentioned accreditation schemes and certification, introduced to ensure safety and sustainability standards are met, have hindered our rate of decarbonisation. There is a dizzying array of accreditation on offer, and the type sought – whether EPC, BREEAM or otherwise – often appears to depend on target audience rather than substance.
The UK Net Zero Carbon Buildings Standard, set for launch by the end of 2025, seeks to remedy this and align certification across the built environment, but things are moving too slowly. There is no doubt that standardisation is vital, but its progression must match the pace of climate change – and crucially, we cannot forget the role embodied carbon has to play in reaching net zero.
EPC in the spotlight
Take EPC ratings, for example. The legislation requires all commercial buildings to reach an EPC rating of C or above by 2028, leaving thousands of properties to be demolished and rebuilt when we inevitably fail to meet this target. This begs the question: is this the outcome we were aiming for? While there is a considerable stock of older buildings available for development, these projects are often blocked by local authorities on the grounds of failing to meet sustainability standards.
To unlock the potential of retrofit here, we must consider the benefits of a dual track system that will exempt specific buildings from this system. Some buildings, while fundamentally unable to meet the sustainability accreditation sought by occupiers and local authorities, are not inherently poor quality buildings. These buildings should not be written off from the offset, but rather considered afresh from a retrofitting standpoint.
Embodied carbon and the economics of retrofit
With operational carbon decreasing thanks to increased energy efficiency and renewable energy, it is now essential that we focus on embodied carbon in existing buildings if the UK is to hit net zero carbon goals.
However, schemes often lend themselves to new developments as older buildings come with an existing list of undesirables depending on the accreditation sought, albeit they can preserve the embodied carbon from previous construction. In addition, greater focus on the requirements and expectation of occupiers has put increased pressure on building owners to prioritise making prime rents and maximising investment value. In this scenario, retrofit comes with a lot of complexity. Often projects can retain only 25% of an original building, call it a retrofit and still claim net zero. This truly is against the spirit of the legislation. Common sense dictates if 75% is new, that’s a significant amount of new embodied carbon. Nonetheless, the industry celebrates, certificates and rewards these schemes with large rents and investment values.
Similar rewards should exist to motivate developers to retrofit and repurpose existing buildings: there are tax incentives for new builds while none exist for retrofitting and repurposing. Any loss made by the government on subsidies will be made back; in the long-term there is an economic motivation for retrofitting. Research shows that modernising ageing buildings could cut global energy demand by 12% and generate huge savings financially and for the environment.
Life cycle assessments
There appears to be an increasing disconnect between what we are aiming for and the reality of the situation. The luxury of time to make inefficient buildings run more efficiently with a decarbonised grid is running out and we are spending embodied carbon to do so. With each carbon spend there should be a life cycle assessment – where embodied and operational carbon are calculated across 60 years to give a whole life carbon assessment.
Operational net zero may be achieved through renewables but embodied carbon comes from the materials used, whether for retrofit or new build, and dealing with this must be where our collective focus lies. Additionally, design for circularity and disassembly shouldn’t be end of life matters. Where retrofit is occurring to satisfy EPCs now, all efforts should be made to re-use and recycle existing materials.
This article appeared first in BE News on 21 July 2025
Want to hear more from us? 
