Episode 213 - Net Zero Carbon Buildings Standard Version 1

This week is a follow up episode from episode 135 covering Version 1 of UK Net Zero Carbon Buildings Standard. This episode content meets PC3 - Legla Framework & Processes of the Part 3 Criteria.

Resources from today's episode:

Websites:

• UK Net Zero Carbon Buildings Standard — Version 1 download: https://www.nzcbuildings.co.uk/the-standard
• Verification information and Verification Primer: https://www.nzcbuildings.co.uk/verification
• RIBA professional feature — Version 1 explained: https://www.riba.org/work/insights-and-resources/professional-features/uk-net-zero-carbon-buildings-standard-explained/
• RIBA professional feature — What does in-use performance mean?: https://www.riba.org/work/insights-and-resources/professional-features/uk-net-zero-carbon-buildings-standard-what-does-in-use-performance-mean/
• CIBSE — Version 1 launch: https://www.cibse.org/policy-advocacy/news/the-uk-net-zero-carbon-buildings-standard-version-1-is-here/
• https://www.ribaj.com/intelligence/how-the-uk-net-zero-carbon-buildings-standard-works-for-architects/?utm_campaign=27/01/2026 Editor's cut&utm_content=How the UK Net Zero Carbon Buildings Standard works for architects&utm_term=&utm_medium=email&utm_source=Adestra

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Transcript

Episode 213:

Hello and Welcome to the Part3 with me podcast. 

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I am your host Maria Skoutari and this week we are picking up from Episode 135, where I covered the pilot version of the UK Net Zero Carbon Buildings Standard and today we will be running through Version 1 of the standard. Todays’ episode meets PC3 of the Part 3 Criteria.

If you have not yet listened to Episode 135, I would really encourage you to go back and do that first. In that episode I covered everything you need to know about the Standard itself, what it is, why it exists, the five key principles, how it is structured, the metrics it uses, and what architects specifically needed to know at the time of the pilot.

Now in today’s episode its not about explaining the Standard from scratch. Today is about what has actually happened since and crucially, what has changed now that Version 1 has been officially published. So Version 1 officially launched on the 10th of March 2026, and it marks the moment this Standard moves from something the industry was preparing for to something the industry can now actively use. So a building now can be verified as 'Net Zero Carbon Aligned' after providing at least 12 months of actual performance data, moving beyond theoretical design-stage predictions and the standard sets out an industry‑backed methodology for defining and verifying net zero buildings, which cuts through years of fragmented guidance and helps eliminate misleading sustainability claims. 

Before we dive into Version 1, let’s run through a quick summary of what is new in Version 1 compared to the pilot release:

• A full Verification methodology: This was the missing element from the pilot, now completed in partnership with Bureau Veritas as the appointed Verification Administrator, with formal verification opening in Q2 of 2026.
• A Deeming to Satisfy Annex, formerly referred to as Equivalence, this provides an alternative conformity route where direct evidence collection is not possible, particularly relevant for existing and heritage buildings.
• A PC On-Track verified check which is an optional independent check at Practical Completion to confirm whether a building is on track to meet the Standard once in use, bridging the gap before twelve months of occupancy data is available.
• Separate landlord and tenant routes to verification which is a new mechanism allowing landlords and tenants in commercial buildings to pursue verified status independently for their respective spheres of control.
• A Verification Primer which will be a new supporting resource published alongside Version 1 that explains the verification process, evidence requirements, programme and indicative costs in accessible terms.
• A How to Use the Standard flowchart to be used as a practical step-by-step guide for project owners and design teams, outlining requirements for different project types and stages.
• Addition of a Delineation Annex, providing clarity on how to define the boundaries of an assessment for complex, mixed-use or phased buildings.
• And updated clarity and usability improvements throughout that have been informed by feedback from the 204 projects that participated in the pilot testing programme.

We will be covering each of these in detail as the episode goes on. But first, let us look at what happened during the pilot testing phase and how we got to Version 1.

From Pilot to Version 1: What Happened in Between:

When I recorded Episode 135, the pilot version had just been published and the pilot testing programme was anticipated to begin in early 2025. That programme has now run its course, and the volume of engagement it generated was remarkable. In total, 204 pilot projects came forward to test the Standard against real buildings. Those projects fed back detailed information on the usability and clarity of the Standard, how achievable its requirements were in practice, and what data architects and project teams were, and were not, able to collect.

That feedback was analysed, collated and shared in a Pre-Launch update in December 2025, followed by a further update in February 2026 ahead of the March official launch. The insights gathered from those 204 projects directly shaped what ended up in Version 1. So this is genuinely a Standard that has been stress-tested on live projects and refined accordingly.

One of the most useful things to come out of the pilot testing process was granular sector-by-sector feedback on data availability and achievability. Teams gave feedback on which mandatory requirements were straightforward to evidence, and which ones presented real challenges in terms of data collection. That information has informed both the technical content of Version 1 and the supporting resources that have been published alongside it.

Now, let’s look at what is actually different in Version 1:

The pilot version, intentionally excluded the verification methodology. Sections 6 and 7 of the Standard, covering verification and conformity communication, were explicitly listed as not yet provided. That was always the plan, verification was always going to come with Version 1. But the significance of it now being there cannot be overstated, because without verification, a building could not formally claim Net Zero Carbon Aligned status. Now, with Version 1 it can.

Beyond verification, as mentioned at the start, Version 1 has been updated for clarity and usability throughout, and it introduces a number of new Annexes that did not exist in the pilot version. These are worth understanding individually, because each one addresses something specific that either arose from pilot testing feedback or reflects how the industry actually operates.

Now, lets start with Verification and what it means in practice:

This is a critical part of the standard to spend more time understanding as it has direct practical implications for how architects advise and support their clients.

So, third-party verification is mandatory if a building is to make any formal claim of Net Zero Carbon Aligned status under the Standard. You cannot self-certify, and claims made without verification are not recognised under the Standard's framework. Verification will be carried out by Bureau Veritas as Verification Administrator. Bureau Veritas was confirmed during this period as the Standard's preferred Verification Administrator meaning they will be the body that will oversee and run the formal verification process. Their involvement in the final stages of developing Version 1 has been central to ensuring that the verification methodology is not just theoretically sound but operationally workable. Initially, they will conduct verifications directly in-house. Over time, they will develop a verifier training and accreditation scheme that will open verification services to the wider industry, but that is a later development.

Alongside Version 1, a Verification Primer has been published. It sets out the verification process in accessible terms, including what evidence is required at each stage, what the programme looks like, the roles and responsibilities of each party involved, and indicative costs. It is available to download for free from the NZCBS website.

Now in terms of the actual verification process, the first practical step for any project intending to pursue verification will be registration. A registration portal is currently being finalised and is expected to go live in the weeks following the Version 1 publication. Registration is the formal declaration of intent as it adds your building to a publicly visible UK Net Zero Carbon Buildings Standard Register of Buildings, which will be listed on the Standard's website. To register, you will need to provide key information about the building and the claimant, agree to the terms and conditions, and pay a registration fee. Verification itself is expected to open fully in the 2nd quarter of 2026.

It is also worth understanding at this stage what the verification process actually asks for. Buildings undergoing verification will need to submit evidence to a verifier covering each of the Standard's mandatory requirements. That evidence must include at least twelve months of measured, in-use energy performance data from real occupancy, not design-stage modelling. This is not a documentation exercise, it requires that systems and processes for data collection have been in place and functioning throughout the building's first year or more of operation. This is because real-world performance depends on how people actually use the space, which can differ wildly from computer models. By waiting a full year, the assessment captures a complete cycle of seasons and operational demands.

So that’s the new verification process set up under Version1, now let’s look the next key part of the standard which is currently known as ‘Deeming to Satisfy’, this was formerly known as Equivalence:

During the pilot testing phase, one of the routes being discussed was referred to as ‘Equivalence', a mechanism for projects that could demonstrate conformity through an alternative but equivalent methodology where direct evidence collection was not possible. Version 1 has now formalised and renamed this as 'Deeming to Satisfy'. The name change is deliberate to reflect the same principle used in building regulations, where meeting specified conditions is accepted as satisfying a requirement even where direct measurement may not be available. This is particularly relevant for certain existing building types and heritage buildings where some of the Standard's data collection requirements may be genuinely difficult to fulfil.

Moving on to next checking process introduced in Version 1, the PC On-Track verified check:

Now this is an optional but potentially very valuable new addition. Because the Standard requires measured in-use performance data from at least twelve months of occupation before a building can achieve full verified Net Zero Carbon Aligned status, there is inevitably a gap between Practical Completion and the point at which verification can be completed. The PC On-Track verified check is designed to bridge that gap.

It is an independent verified check, carried out at Practical Completion, that confirms whether the building, as designed and built, is on track to meet the Standard once it is in use. It is not mandatory, and it does not grant verified status on its own. But it provides clients and design teams with a credible, independent interim marker, and it is something that clients wishing to demonstrate progress on their net zero commitments during the construction phase are likely to find genuinely useful. There is a dedicated PC On-Track Submission Proforma being developed to support this process.

The next route covered in Version 1 is the Landlord and Tenant Routes to Verification:

This is one of the additions which will likely be the most significant for architects working in the commercial sector. In a typical commercial building, like an office, a retail unit, a hotel, and so on, the landlord and the tenant have different spheres of control. The landlord is responsible for base building systems like the structure, core plant, common areas, central heating and ventilation. And the tenant fits out and operates their own space, and in many cases controls the majority of the energy that is actually consumed in use.

The pilot version of the Standard did not have a clean answer for how to handle this split. Version 1 now does. There are now separate routes to verification for landlord-controlled elements and tenant-controlled elements, meaning each party can pursue verified status for their sphere of control independently. This is a pragmatic recognition of how commercial real estate actually works, and it removes a significant obstacle that would otherwise have made the Standard inaccessible for large parts of the commercial property market.

And next, Version 1 provides the Delineation Annex:

This Annex addresses a genuinely tricky practical challenge: where exactly does the boundary of your assessment sit? For a straightforward single-use new-build, this might seem obvious. But for mixed-use developments, phased projects, or buildings with complex tenure arrangements, defining what is and is not included in the assessment can be far from simple. The Delineation Annex provides clarity on how to draw those boundaries consistently which in turn ensures that verified claims are comparable and meaningful across different project types.

Now, back in episode 135, I mentioned the performance gap, which is the discrepancy between what buildings are predicted to consume at design stage and what they actually consume in use, as one of the key problems the Standard is designed to address. With Version 1 now live and verification imminent, this moves from being a principle to being a practical requirement that architects need to actively plan for:

CIBSE, one of the Standard's founding organisations, has long documented the performance gap as a systemic problem in the UK built environment. Buildings routinely consume significantly more energy in use than their models predicted, sometimes by a factor of two or more. The Standard tackles this head-on by making in-use performance data mandatory. There is no route to verified Net Zero Carbon Aligned status based on design-stage predictions alone, no matter how detailed or well-intentioned those predictions are.

For architects, this has a concrete consequence: post-occupancy evaluation can no longer be an optional extra or a nice-to-have that gets dropped when fees are squeezed. If your client wants verified status, you need a clear plan for how twelve months of real performance data will be collected, who will collect it, how it will be stored and reported, and who will be responsible for it.

It also means having a frank conversation with clients about what in-use performance data actually captures. Unlike Energy Performance Certificates, which assess regulated energy loads only, the Standard measures actual energy consumption including unregulated loads, everything from computers and kitchen appliances to plug-in equipment and IT servers. This is a more complete and more honest picture of a building's real carbon impact, but it also means the data collection requirement is broader than many clients and design teams may initially assume.

The primary metric for in-use performance stated within the Standard is Energy Use Intensity (EUI), which measures the total energy used per square metre over a year. This includes everything from heating and cooling to 'plug loads' like computers and kitchen appliances. Crucially, even energy generated by on-site renewables, like solar panels, is included in this measurement to provide a transparent picture of the building's total energy appetite. In-use performance also looks at other environmental impacts that only become clear once the building is running, such as:

• Operational water: The carbon emissions associated with supplying water and treating wastewater must be reported
• Refrigerant leaks: Air conditioning and heat pump systems use gases with high global warming potential. If a building’s refrigerant charge is large enough, any leakage must be measured and converted into its carbon equivalent
• Grid management: Buildings are expected to be 'good citizens' of the national energy grid. This is measured through electricity demand management, which tracks a building's ability to reduce or shift its energy use during peak times

So before we conclude, let’s just look at the Broader Picture and why Version 1 matters:

Let’s take a quick moment to step back from the practical detail and reflect on what Version 1 actually represents for the profession and the industry, because I think it is easy to process it as just another standard to be aware of and miss what is genuinely significant about it.

Until the 10th of March 2026, there was no independently verified, industry-agreed, science-led definition of what it means for a building in the UK to be net zero carbon. Claims made by developers, asset managers, and others were, by definition, unverifiable against a common standard. That has now changed. For the first time, a building can be independently verified as meeting a single, agreed, publicly accessible methodology and that verified status can be communicated formally and meaningfully.

This matters enormously for the commercial property market, where Environmental, Social and Governance reporting requirements are becoming increasingly demanding, and where investors, occupiers and funders are scrutinising sustainability credentials more carefully than ever before. Verified Net Zero Carbon Aligned status under this Standard is a credible, third-party-backed claim that carries weight in that context in a way that self-declared net zero claims simply do not.

It also matters for architects specifically, because it shifts the conversation from qualitative sustainability ambitions to quantitative, verifiable outcomes. The profession has historically been better at articulating sustainability intentions than at demonstrating measurable, comparable results. The Standard provides an infrastructure for doing the latter and architects who understand it well, who can guide clients through it, and who can structure their appointments to support its requirements are going to be significantly more valuable advisers than those who are not familiar with it.

Looking ahead, Version 1 is not the end point. Feedback on Version 1 is being actively sought via a survey on the Net Zero Carbon Buildings Standards website, and the Standard will continue to evolve. Guidance specifically for existing and heritage buildings is planned, as is guidance for the legal profession on how to incorporate the Standard into contracts, which is a development that will make it far easier to embed verified net zero requirements into development agreements, leases, and procurement documentation.

So let’s conclude with what architects should be doing right now with the release of Version 1 and how the standard compares to existing guidance:

So with Version 1 published and verification on the immediate horizon, what should we actually be doing?

First, professionals should make sure to read the Verification Primer. It is free, it is accessible, and it says exactly what the verification process involves. Even if you do not currently have a project in the pipeline that is targeting verified status, understanding the process will help you have better conversations with clients and make you a more informed adviser. It also alerts you to what data collection infrastructure needs to be in place long before verification becomes relevant.

Second, if you do have a relevant project, the time to raise the Standard with your client is now, not when they ask about it, and certainly not after Practical Completion. Whether a client wants to pursue verified status or simply wants to design to the Standard's targets without formal verification, the implications for project programme, system selection, specification, and post-occupancy arrangements need to be factored in from the outset.

Third, think carefully about your appointment and fee structure in relation to post-occupancy involvement. The Standard's verification requirement creates a legitimate, evidence-based argument for architects to be engaged beyond Practical Completion to support data collection and reporting. This is an area where the profession has historically struggled to maintain continuity of involvement, but the Standard provides a clear, client-facing rationale for why that involvement has real commercial value.

Fourth, if you work on commercial buildings, the new landlord and tenant routes to verification open up a conversation with asset owners and property managers about how the Standard applies specifically to their business model. Landlords who want to make credible net zero claims for their assets now have a formal pathway to do so, independently of their tenants. Understanding those routes well enough to explain them clearly to a client is a meaningful piece of expertise.

And fifth, start paying attention to verification costs and programme. The Verification Primer includes indicative pricing, and while verification is a cost that falls to the building owner or claimant rather than the architect directly, understanding what it involves helps you brief clients accurately and manage expectations. Verification is not an afterthought it is the culmination of a deliberate, evidence-based process that needs to have been built into the project from the beginning.

In terms of how the UK Net Zero Carbon Buildings Standard compares to existing gudiances, it:

• Aligns with the RIBA Climate Challenge in that those who join the challenge, must also provide in-use energy and water performance data for the building one year after completion. The challenge also requires that information be obtained from actual meter readings or utility bills over a full 12 month period. Both requirements are designed to identify and analyse the performance gap.
• The standard also aligns with the RIBA awards programme relating to in-use data, derived from 12 months of occupancy for energy and potable water use is mandatory for entry.
• And it also aligns with the RIBA’s Plan for Use guide, that recommends post-occupancy evaluations are carried out on all projects.

Let’s sum what we ran through today:

• Version 1 of the UK Net Zero Carbon Buildings Standard was published on the 10th of March 2026, marking the transition from a pilot that the industry was preparing for to a fully operational standard that the industry can now actively use.
• The pilot testing programme ran through 2025, with 204 projects providing feedback that directly shaped Version 1. This is a Standard that has been genuinely tested on real buildings and refined accordingly.
• The most significant addition in Version 1 is the full verification methodology, developed in partnership with Bureau Veritas as Verification Administrator. Without this, no building could formally claim verified Net Zero Carbon Aligned status. Now it can.
• Version 1 also introduces four important new Annexes: Delineation, Deeming to Satisfy, the optional PC On-Track verified check at Practical Completion, and separate landlord and tenant routes to verification.
• Verification is expected to open formally in Q2 of 2026. The Verification Primer, published alongside Version 1, sets out the process, evidence requirements, programme and indicative costs read it if you have a project that may pursue verified status.
• The mandatory requirement for twelve months of measured in-use performance data is no longer a future ambition it is a live requirement. Architects need to plan for post-occupancy data collection from Stage 1, structure their appointments to support that involvement, and have informed conversations with clients about what that data actually needs to capture.