MBIE has provided a guidance document for the changes to H1 Energy efficiency and the transition dates for coming into effect. The document outlines the changes to insulation requirements and when they affect different areas of the country.

You can find the document here https://www.building.govt.nz/assets/Uploads/building-code-compliance/building-code-updates/transition-period-for-the-energy-efficiency-housing-outcome-of-consultation-building-code-update-2022.pdf