The UK Net Zero Carbon Buildings Standard (UK NZCBS) defines how buildings can achieve net zero carbon alignment. It sets limits for embodied carbon, operational energy, district heating, fossil fuel use, refrigerants, and more, creating a science-led framework to decarbonise the built environment in alignment with the UK's climate goals.
The UK Net Zero Carbon Buildings Standard (UK NZCBS) is a comprehensive framework aimed at defining and verifying what it means for buildings in the UK to truly be net zero carbon. Developed through a collaboration of leading industry organisations, including BBP, BRE, RIBA, RICS, LETI, and UKGBC, the standard provides clear, science-led guidance for reducing the carbon impact of the built environment and ensuring that all building developments are net zero carbon aligned.
The pilot version, launched in September 2024, marks the start of industry-wide testing. It sets limits and targets that help ensure new and existing buildings meet the UK’s climate goals by reducing their carbon impact across the entire building lifecycle.
Before the release of the UK NZCBS, there was no single, agreed-upon methodology for determining what qualifies as a net zero carbon building. This led to confusion and inconsistent claims, often leaving stakeholders unsure of whether buildings were truly aligned with the UK’s 1.5°C climate targets.
The UK NZCBS was created to resolve these issues, offering clarity and technical rigour. Its primary impact will be the reduction of carbon emissions in both new buildings and existing buildings across a wide range of 13 sectors, ensuring the built environment plays its part in achieving net zero carbon by 2050.
The standard is designed for a wide range of industry professionals, including:
Developers and contractors: Ensuring projects meet carbon reduction goals.
Architects and engineers: Guiding design processes to minimise carbon impact.
Asset managers and owners: Verifying that their properties align with net zero carbon targets.
Investors and financiers: Offering confidence that projects are on track to meet long-term climate commitments.
The UK NZCBS is complementary to existing standards like BREEAM, LETI, and the RICS Whole Life Carbon Assessment Standard. While certifications like BREEAM focus on broader sustainability aspects, the UK NZCBS zooms in on carbon management across a building’s lifecycle. It aligns particularly well with RICS Professional Standard (version 2) in setting out how to perform embodied carbon assessments, creating a seamless bridge between different sustainability certifications.
The UK NZCBS pilot version sets out ambitious but fair limits, targets, and reporting requirements to ensure that buildings are truly net zero carbon aligned. These requirements span multiple aspects of building design and operation, ensuring that both embodied and operational carbon are accounted for.
There is also an optional reporting requirement for carbon offsetting, allowing projects to voluntarily disclose offset actions, although the focus remains on minimising direct emissions.
The UK NZCBS places a strong emphasis on embodied carbon, which refers to the greenhouse gas emissions resulting from the production, transportation, and assembly of building materials, as well as their end-of-life disposal or recycling. This type of carbon is generated before a building is even occupied, making it a crucial focus for achieving true net zero carbon alignment.
According to Section 5 of the pilot version, the embodied carbon assessment must include both life cycle embodied carbon and upfront carbon. The life cycle embodied carbon accounts for emissions throughout the entire life of the building, from sourcing materials to demolition, while upfront carbon focuses specifically on the emissions generated up to practical completion.
To ensure consistency and accuracy in these assessments, the UK NZCBS requires them to be aligned with the RICS Professional Standard. This standard, developed by the Royal Institution of Chartered Surveyors (RICS), sets out detailed methodologies for calculating and reporting whole life carbon emissions over the lifecycle of a built asset. By adhering to the RICS framework, the UK NZCBS ensures that embodied carbon assessments follow a rigorous and widely accepted approach, promoting transparency and comparability across different projects and sectors.
Aligning with RICS also strengthens the standard’s credibility, as RICS is a trusted authority in the built environment. This alignment allows stakeholders to confidently measure and report their building’s carbon footprint in a way that is both scientifically sound and industry-accepted, making it easier to meet compliance requirements for net zero carbon alignment.
The pilot testing programme, set to launch in early 2025, will be a critical phase for gathering feedback from real-world projects. The aim is to refine the standard and ensure it is both ambitious and achievable across a wide range of building types.
The final Version 1, expected by late 2025, will include a formal verification process for buildings to be certified as net zero carbon aligned. Additionally, new limits and metrics will be added for:
The UK NZCBS is the result of an immense collaboration from over 350 industry experts, with key contributions from the following organisations:
Their collective effort and expertise have created a robust, scientifically sound framework that will drive significant progress in the UK’s decarbonisation efforts. We are appreciative of the hard work that goes into developing such a standard and are grateful for its ability to create a clearer path to net zero in the built environment.