H1 Energy efficiency support

Building Code clause H1 Energy efficiency sets minimum requirements for thermal performance in buildings. The Acceptable Solution and Verification Method that can be used to demonstrate compliance for all housing, and buildings up to 300 m2 are H1/AS1 5th edition amendment 1 and H1/VM1 5th edition amendment 1. BRANZ has produced a number of tools and resources around these. If you wish to use H1/AS1 or H1/VM1 to demonstrate Building Code compliance from 27 November 2026 on, you must use the 6th Edition. Note that the schedule method in the 5th Edition of H1/AS1 does not exist in the Sixth Edition and therefore cannot be used to demonstrate compliance from 27 November 2026.

BRANZ bulletins on the topic include:

• BU672 Specifying floors under H1
• BU670 Specifying windows and doors under H1
• BU677 Specifying roofs under H1
• BU678 H1 Calculation method - housing, and buildings up to 300 m²
• BU685 Insulation of concrete slab-on-ground floors less than 300 m²

Resources and tools

Updated: 18 February 2026