Insight
Top Takeaways on the Net Zero Carbon Building Standard
23 Dec 2024
Tom Roxburgh
Sustainability Consultant
The Net Zero Carbon Building Standard (NZCBS) represents a pivotal step towards achieving rigour and consistency in the approach to (and measurement of) decarbonisation in the built environment. Following a detailed review of the pilot document, Sustainability Consultant Tom Roxburgh shares his key takeaways on the ‘setting and meeting targets’ requirements of the standard, which prioritises early intervention, retrofit projects, and robust compliance mechanisms.
1. Retrofit Over New Construction
The NZCBS emphasises retrofit as the primary focus for achieving net zero goals. While new construction is not excluded, retrofitting existing buildings is heavily prioritised due to its strong potential for lower embodied carbon and increased sustainable resource use.
2. Early Target Setting is Essential
Targets—or “budgets”—must be established as early as possible in the design lifecycle, to guide decisions and ensure alignment with the standard. This proactive approach is vital to meeting the strict embodied and operational carbon limits outlined in the NZCBS.
3. Focus on GIA-Specific Items
The standard’s targets apply solely to elements within a building’s Gross Internal Area (GIA). External features such as photovoltaic panels and landscaping are excluded, ensuring a concentrated effort on buildings’ core emissions.
4. Mandatory Compliance with ‘Report and Meet Limits’
Achieving the standard requires meeting mandatory targets. Without evidence of compliance in these areas, a project cannot be certified. Optional ‘Reporting Only’ items, while not required, are however strongly encouraged to align with best practice and holistic design approaches.
Additional Insights:
Embodied Carbon: Early-stage assessments are crucial, with a focus on upfront carbon (Modules A0–A5) and alignment with the GLA Breakdown Framework.
Operational Carbon: Modelling must surpass SAP standards, with in-use data at Stage 7 being a non-negotiable requirement for certification.
Retrofit Pathways: Incremental or staged retrofit programmes are permissible as long as NZCBS targets are ultimately achieved.
Although the NZCBS remains in its pilot phase, it already provides a very clear framework for decarbonisation of buildings, and could easily be used as best practice guidance until the point at which it formalises as a standard. As well as using the NZCBS, organisations should continue to seek to integrate complementary standards, such as CRREM, into project workflows to further drive meaningful sustainability outcomes.