The New UK Net Zero Carbon Buildings Standard 2024 – piloting towards a brighter future?

Introduction

When all the major industry bodies across the UK construction sector collaborate, people take note. RIBA, RICS, UK Green Building Council, CIBSE, and the Institute of Structural Engineers and more as well as various leading developer, consultant and contractor firms and local authorities have all come together to launch the new, landmark UK Net Zero Carbon Buildings Standard (the Standard).

With input from businesses and individuals in the thousands, using data from over 4,000 projects, this demonstrates a genuine joint effort to encourage the UK built environment industry to embed a net zero carbon ethos into their work and business.

Since the 2010s, it has been increasingly obvious that companies striving for net zero output have struggled to reach an agreed upon definition of net zero, with no common methodology meaning additional work to agree the meaning per project, and a lack of confidence in any net zero claims made. The Standard creates a single definition of a “net zero carbon building” and sets out specific, measurable requirements for buildings to be considered net zero carbon. 

Building Standards

Standards aren’t new to the construction industry – interested parties will already be familiar with examples issued by the British Safety Institute, the International Organisation for Standards and the Eurocodes. They can cover topics as widely ranged as fire safety to drainage to material specifications. While some standards are mandatory, most are not; and this new Standard falls within the voluntary camp. Project teams will have to actively choose to adhere to the Standard, though this will allow them to make marketing claims down the line. 

There are some limited standards already available in the net zero carbon space, which some may be familiar with: two examples include the NHS Net Zero Standard and the Scottish Net Zero Public Sector Buildings Standard. Carbon management is also considered in PAS 2080. The Standard is intended to align with these existing Standards, albeit with a much wider remit.

The NZC Pilot

The Standard was dreamed up by founding partners in early 2022 – a team which from November 2022 sought engagement from potential users of the Standard. Almost two years of work have gone into utilising project data and the opinions of interested professionals, and creating a science- and industry-backed document that covers building uses from commercial, residential, retail and office space to culture, leisure, healthcare, education and storage. 

22 September 2024 saw the publication of the pilot, a draft of the Standard containing the overarching requirements, specific measures for elements such as embodied carbon and operational energy, and an in-depth table of numerical limits by building type, purpose and year. The pilot version is missing some information (in particular, data for specific building types and details of the verification process), though it does help us to understand how the Standard will function: 

• A claim of conformity associated with the Standard is an expression limited to a 12-month period, during which data on the building’s operational energy usage and other specific data points has been collated and verified;
• Verification is not an internal process, but expected to be carried out by a third party, after occupation at above set percentages for the preceding 12 months (for unoccupied buildings, operation for the period is sufficient);
• A net zero claim associated can either come in the form of “Net Zero Carbon Aligned Building”, or “Net Zero Carbon Aligned Building (with offsets)” – carbon offsetting is not discouraged but cannot replace compliance with the mandatory targets; and
• Where a building later falls below the requisite targets, it can no longer use the net zero claim except by reference to prior compliant years.  

In future versions, we can expect to see a more complete data set, and evolution of the document to include potential delineation for multi-use buildings with separable areas, heritage buildings with their unique challenges, and even the inclusion of recognised standards with which equivalence can be demonstrated.  

What’s the Point?

So, why is it that so many key industry players have collaborated to this end? Science shows that climate change is affecting both people and the natural ecosystems we are part of. As temperatures rise, those effects are exacerbated: to avoid the worst effects currently projected, global temperature rise should be limited to an average 1.5 degrees Celsius. This requires concerted effort from individuals, businesses, industries and nations. 

Politics is a key part of this, but governments across the world have competing agendas and potentially more short-term goals, meaning that concerned actors are choosing to take on responsibility for their own circles. In short, it’s a collaboration for the greater good, and the Standard aims to keep the UK’s built environment to its share of those carbon/energy budgets. 

There’s another benefit too: it allows for harmonisation around a single definition of what net zero carbon means for the built environment, and uniformity in claims of net zero buildings. Consistent rules in these regards, and in the output to be achieved, allow for creative effort to be spent in finding new ways to become net zero – instead of in agreeing what net zero is. 

What’s Next?

As the Standard is a pilot version at this stage, interested parties are expecting a period of industry stress testing and review. Over a substantial period, prospective users will be able to test the limitations of the Standard as well as the benefits; expect this feedback to be incorporated into a final version for publication in 2025 or beyond.  

A pilot testing scheme is being launched later this year and test projects are being sought to understand how implementation of the Standard functions, and how it might be improved. Some data is still outstanding (which we’d expect to be rectified by the final version) including life cycle embodied carbon limits for new works and upfront carbon limits for reportable works. It’s likely the pilot schemes will be a key part of this, as will additional contributions from involved parties beginning to apply the Standard to new projects and retrofit works. 

One key area that the Standard doesn’t currently apply to is infrastructure, and time will tell whether there’s any intention to try to pull together data for common types of infrastructure projects or other non-“building” construction going forwards. 

In Practice

With so many voluntary standards out there, we know not all of them can be adopted. However, it’s certainly possible that this Standard will encourage a focus on net zero carbon projects from parties who wouldn’t previously have considered it – and it will almost certainly make pursuing net zero much easier for those already working to achieve that status. 

Those looking to use the Standard will benefit from rigorous data practices, and early adoption – utilising its metrics right from project inception and creating and maintaining quality records will be key for later verification of any net zero claims. 

There will inevitably be kinks to iron out as pilot projects progress and as feedback is received, as well as new opportunities to consider supplementing the base Standard. The more that the Standard aligns with equivalents as they emerge, whether from other bodies, sectors or internationally, will likely make for greater uptake and improve outcomes. 

Public adoption of the Standard by local authorities, developers and contractors, and even encouragement from across the industry will give the Standard the boost it likely needs to move from novel to mainstream. The more visibility the Standard can garner, the more it will be considered for use on upcoming builds. The importance of buy-in cannot be underestimated; a few key endorsements could completely revise the type of project and stakeholder choosing to use it. 

On the legal side, we’d expect to start seeing references to the Standard in technical documents and specifications, either as a goal or an obligation on not only design teams but contractors and consultants. As always, careful drafting is key, but this will surely be a positive for the industry and for the environments we’re building in.