As New Zealand’s H1 energy-efficiency requirements continue to reshape residential design, Knauf Insulation New Zealand has developed a FREE online calculator designed to help architects, designers and specifiers navigate the transition toward more performance-based thermal design.
The Knauf Insulation H1 Calculator supports both Version 5 and Version 6 of the H1 regulations and is built around the Calculation Method, which will become increasingly important following the removal of the Schedule Method in November 2025. Rather than relying on rigid prescriptive R-values alone, the Calculation Method allows designers to balance the performance of different building elements to achieve overall compliance more efficiently.
That flexibility is becoming increasingly valuable as designers work to meet higher thermal-performance targets while still managing construction costs, glazing ratios and overall buildability.
Available free online, the calculator has been developed as a practical alternative to complex spreadsheets and manual calculations. The platform guides users through a simplified three-step process, allowing them to model roofs, walls, glazing, floors and slab construction within a single workflow.
The tool then compares the proposed design against a reference building model to determine compliance under the H1 Calculation Method. Users can test different insulation and glazing combinations, explore trade-offs between building elements and optimise designs to find more cost-effective pathways to compliance.
Rather than simply checking minimum requirements, the calculator is designed to support better-informed design decisions earlier in the process. In some situations, the flexibility of the Calculation Method may even allow designers to reduce or eliminate additional slab insulation requirements by improving thermal performance elsewhere within the building envelope.
Once complete, users can instantly generate and download a project-specific H1 compliance report, helping streamline design documentation, consultant coordination and building consent preparation.
The calculator forms part of Knauf Insulation’s broader H1 support platform, which includes technical guidance, insulation solutions, specification support and educational resources designed to help the industry adapt to New Zealand’s evolving energy-efficiency standards.
As H1 requirements continue to move the industry toward more holistic building-envelope design, tools that simplify modelling and improve design flexibility are becoming increasingly important across both residential and light commercial projects.
The Knauf Insulation team will also be demonstrating the H1 Calculator platform at upcoming Design Experience events in Christchurch, Auckland and Wellington.
Learn more about Knauf Insulation via their website: https://knauf.com/en-NZ/knauf-insulation/h1 and the Knauf Insulation H1 Calculator at: https://knauf.com/en-NZ/knauf-insulation/services/tools/h1-calculator.