by Austen Bates, Head of Sustainability (Building Services), Ramboll
The UK’s journey towards achieving its decarbonisation goals has taken a significant step forward with the introduction of the UK Net Zero Buildings Standard. This standard, launched in September, is designed to align buildings with net-zero targets. However, while this is a crucial step in the right direction, there remains much to be done to fully realise our decarbonisation targets.
Setting The Standard
The recently launched Pilot UK Net Zero Buildings Standard (commonly referred to as “The Standard”) is the first cross-industry standard for net-zero aligned buildings in the UK. It has been developed with input from several leading organisations and covers performance limits for existing buildings in use. Given that 80% of the UK’s current building stock will still be in use in 2050, being able to address their performance will prove key to delivering the UK’s 2050 Net Zero Carbon Emissions Target.
The Standard also provides clarity on what constitutes a net-zero building, which has been lacking until now. This will help curb the risk of greenwashing and ensure claims regarding building performance are based on measurable, third-party verified data, and represents a critical step for the UK in leading the way towards a net-zero built environment.
Framework and Challenges
The Standard imposes specific limits and targets that apply to completed works, with reporting windows varying from five years for initial disclosure of embodied carbon to rolling 12-month windows thereafter. These limits are determined based on the extent of the work being undertaken, whether it involves new build, retrofit, or reportable works. There are concerns, however, that the definition of works may get interpreted and encourage “gaming” of the system to avoid new build requirements. That said, transparency will be key, as any building claiming to be net-zero aligned will need to undergo third-party verification.
Circular Economy and Re-use
A significant challenge of meeting The Standard’s requirements is the issue of embodied carbon. For instance, to meet The Standard limits in 2040, the construction industry will need to focus on both reducing emissions through decarbonising the material supply chain and reusing materials in buildings.
Nevertheless, the question remains: How will the industry deliver on this? How can the risks associated with existing buildings be managed to encourage innovative projects and create a strong business case for re-use?
In 2021, Ramboll co-authored the “Business Case for Circular Economy” with the World Building Council for Sustainable Development, which highlighted some emerging business cases for re-use. However, at the time, low virgin material costs and limited carbon policies slowed progress. Fast forward to 2024 and the UK’s planning policy landscape has shifted considerably.
Several London boroughs have adopted a “retrofit first” policy, prioritising retaining and re-using existing buildings over more carbon-intensive new development. Additionally, pre-redevelopment audits are increasingly becoming a requirement. These audits assess a building’s suitability for re-use or adaptation, which can help to reduce the risks associated with re-use. A successful example is British Land’s 3 Sheldon Square project, where Ramboll developed a scope to validate the re-use of building service components. This resulted in cost savings of approximately 35% compared to a new build without needing to compromise on building performance. The measured ‘as built’ upfront embodied carbon for the project stood at 124kg CO₂e/m², a figure that aligns with the 2040 ‘New Works’ limits within The Standard. This demonstrates that re-use, rather than relying on new materials, plays a key role in achieving Net-Zero performance.
While the UK’s Net Zero Buildings Standard is a major step forward, the path to decarbonisation will require more than just meeting these standards. The UK’s circularity metric currently stands at around 7.5%, highlighting the country’s reliance on virgin materials which are often sourced through international trade. To achieve net-zero targets, shifting towards re-used materials and away from those that only increase our carbon emissions must become a priority.
Ultimately, while the Standard represents positive progress, there is still plenty for the UK to do in terms of embracing circularity and driving the deep decarbonisation needed to meet its long-term climate goals.
