The UK Net Zero Carbon Buildings Standard (the Standard) was established in 2022 to provide a consistent, industry-agreed definition of net zero carbon which could cut through greenwash and robustly demonstrate in use performance. Following input from more than 350 industry experts, the Standard (Version 1) was published this March, and its verification scheme opens today, July 28.
The Standard covers both the methodology to measure a building’s carbon and energy performance, and the definition of a Net Zero Carbon Aligned building. The definition is conveyed through a number of mandatory limits, targets, and requirements; including removal of fossil fuels; introduction of on-site renewable electricity generation; and limits on upfront embodied carbon and measured in-use energy consumption. To demonstrate these requirements have been met, measured in-use building data must be submitted for third party verification.
Using the Standard is voluntary and allows claimants to align buildings to a 1.5°C science-led pathway, which was created through downscaling UK carbon and energy budgets. Offsets may not be used to meet any of the Standard’s limits, but they can be used once the mandatory requirements have been met to address the residual carbon.
What role does verification play in a Net Zero Carbon Aligned building?
Independent third-party checking is mandatory and means that any claims under the Standard are robust. Verifiers will apply expert knowledge to affirm the quality of the evidence, and whether it substantiates the conformity claim. The introduction of verification is a significant milestone for the industry, giving confidence that only buildings with demonstrable low carbon outcomes can earn Net Zero Carbon Aligned status.
The evidence requirements include 12-months of in-use energy data, as well as the as-built upfront embodied carbon data. To build confidence prior to this point, buildings can choose to undergo a verified check at Practical Completion to determine whether the building is On Track to meet the Standard in use.
An alternate designation called a Performance Evaluation is also available for buildings that may not yet meet all of the Standard’s requirements. This route requires buildings to undergo the same third-party verification process, using the Standard’s metrics and assessment methodology. The output is a Performance Evaluation Report: a robust ‘report card' of the building’s decarbonisation progress. This route provides industry with a consistent and evidence-driven way of reporting in-use building performance.
"Independent verification is an important step in giving customers, investors and stakeholders confidence that buildings are performing as intended. As demand for high quality, high efficiency logistics space continues to grow, having a robust standard helps create greater transparency and supports more informed decision making across the industry. At Prologis, we're committed to delivering buildings that not only reduce environmental impact but also create long term value. Pursuing verification demonstrates that commitment and reflects our belief that independent assessment has a key role to play in a net zero built environment." Martin Cooper - Vice President, Development Management UK, Prologis
How does a building get verified?
Bureau Veritas (BV) has been appointed as the Standard’s Verification Administrator. In this role it runs and oversees the verification scheme and will also act as the first verifier. Wider verifier training and accreditation will open to the industry in 2027.
In order to verify a building, it must first be registered with Net Zero Carbon Buildings Standard Ltd, then a quote can be obtained from Bureau Veritas to carry out the verification. Once appointed, Bureau Veritas will verify the claim using the methodology defined in the verification guidance available on the UK NZCBS website.
Verification itself is a comprehensive, evidence-based assessment conducted by Bureau Veritas, examining submitted documentation against the Standard's defined criteria to confirm that mandatory requirements, including fossil fuel removal, on-site renewable generation, embodied carbon limits, and measured energy performance, have genuinely been met. This rigorous third-party review ensures that Net Zero Carbon Aligned claims rest on verified facts, creating an auditable record of performance.
Claims apply for the one-year retrospective period within which the building’s energy consumption was monitored.
An explanatory webinar by UK NZCBS and BV on 15 September will walk through the verification process to support industry understanding.
“The launch of verification under the UK Net Zero Carbon Buildings Standard marks a pivotal shift in the industry, moving from predicted outcomes to measured, independently verified in-use performance. As Verification Administrator, Bureau Veritas will ensure that net-zero claims are accurate, reliable, and backed by rigorous assessment. Our role is to provide an independent, expertise in building performance and carbon assessment, to give investors, occupiers, and stakeholders genuine confidence in building performance. With nearly 200 years of credibility in testing, inspection and certification, we're proud to support the industry's transition towards a low-carbon future.” Antoine Giros, Vice President, UK and Ireland, Bureau Veritas
Addressing the Performance Gap
Verification to the Standard and the availability of Performance Evaluations mark a major shift from design-stage, modelled claims, to measured in-use performance. It evidences the performance gap the industry has long known about, providing a consistent methodology to measure energy use and as-built embodied carbon. Improving confidence in building performance through verified claims gives assurance across the value chain, from investors and funders to developers and occupiers. Net Zero Carbon Aligned buildings will have exemplary performance and low energy bills, as well as enhanced marketability, resilience and futureproofing.
Use of the Standard’s methodology will create industry consistency in the measurement, reporting, and verification of Net Zero Carbon Aligned claims.
"The verification launch is an exciting moment not just for our team who have led the development of the Standard, but also for the hundreds of industry volunteers who have supported it along the way. We are hugely grateful to all our supporters, whose contributions have been essential to us. Our Verification Administrator, Bureau Veritas, are experts in certification. We have jointly established a collaborative partnership during the verification development, and look forward to continuing this now it is up and running. It is now only a matter of time before the first buildings are verified as Net Zero Carbon Aligned. These front-runners will represent environmental leadership within the UK built environment industry and pave the way for many more verifications to follow.” Katie Jackson-Clements, CEO, UK Net Zero Carbon Buildings Standard
As more buildings become verified to the Standard this will allow like-for-like comparison of building performance between peers. It will elevate buildings with robust third party verification of their carbon impacts.
Buildings that have been verified will be featured publicly on the UKNZCBS website, so watch this space.