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The 27 November 2026 change ​

Sources and verification

This page states a regulatory timeline. The dates are drawn from MBIE / Building Performance and BRANZ guidance on the H1/AS1 6th edition and were current at the time of writing. Verify against current MBIE guidance for your consent, since transition dates can be updated.

If you prepare H1 documentation, one date matters: 27 November 2026. From then, the Schedule Method is gone, and residential H1 compliance must use the Calculation Method or the Modelling Method. Thermly implements the Calculation Method, so if you work in Thermly you are already on the surviving path.

What changed ​

MBIE published H1/AS1 6th edition on 27 November 2025. Its biggest structural change is the removal of the Schedule Method - the prescriptive R-value look-up tables by climate zone and element that many designers used as a quick path to compliance.

The 5th edition offered three routes: the Schedule Method, the Calculation Method, and (by reference) the Modelling Method. The 6th edition keeps only the Calculation Method in the Acceptable Solution, alongside the Modelling Method in H1/VM1.

The transition window ​

There is a twelve-month overlap:

  • The 5th edition (as amended) can be used to show compliance until 26 November 2026, and for building-consent applications submitted before 27 November 2026.
  • From 27 November 2026, the Schedule Method can no longer be used. New consent applications must use the Calculation or Modelling Method.

In short: the Schedule Method is available for consents lodged up to and including 26 November 2026, and not after.

What it means for you ​

  • No more schedule look-ups. The simple "meet the zone's roof and wall R-values from a table" path is no longer in the Acceptable Solution.
  • The Calculation Method is the mainstream route. For most residential buildings it replaces the schedule, comparing your building's whole-envelope heat loss against a reference building. This is exactly what Thermly does.
  • The Modelling Method (H1/VM1) remains for cases the Calculation Method does not cover (for example, wall glazing above the cap).

Why Thermly is well placed for it ​

Thermly was built around the Calculation Method, so the 6th edition validates the approach rather than disrupting it. There are no schedule tables to retire and no method change to learn: the tool already computes construction R-values to NZS 4214 and runs the H1/AS1 6th edition whole-building comparison. See How Thermly calculates compliance.

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