> For the complete documentation index, see [llms.txt](https://docs.betterbuilding.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.betterbuilding.io/sign-up-and-plans/news-and-updates/2026/h1-as2-and-vm2.md).
# H1 AS2 & VM2
Updates Now Available
We've released updates for both H1/AS2 and H1/VM2 this morning.
As a quick reminder, the second editions of these two compliance pathways become mandatory on 27 November this year. After that date, every project needs to use the second edition of H1/AS2 & H1/VM2 for buildings greater than 300 m2.
There's a fair bit documented in the compliance pathways themselves, but here's the overview.
## **H1/AS2**
The schedule method is out, calculation method only now. Minimum construction R-values for roofs and floors have been dropped, and the calculation method flexes more generally on construction R-values. Mixed-use buildings can be treated as one thermal envelope or split into multiple, whichever fits.
Framed wall thermal resistance has been recalculated to better reflect thermal bridging from framing, which drops the reference building's wall R-value, so don't reuse old comparative numbers. Heated ceilings, walls and floors are now exempt from minimum R-values when they're solely in bathrooms. Area calculations use overall internal dimensions now.
Appendix E (slab-on-ground) covers mixed cladding types and partial slab edge insulation, with more performance tables for a wider range of area-to-perimeter ratios. Insulation thermal resistance now comes from the Building Product Specifications, not AS/NZS 4859.1, which has been removed. Everything else is reference updates, definition tidying and general cleanup, no change to required performance.
{% hint style="info" %}
Grab H1 AS2 [here](https://www.building.govt.nz/assets/Uploads/building-code-compliance/h1-energy-efficiency/asvm/h1-energy-efficiency-as2-second-edition.pdf)
{% endhint %}
## **H1/VM2**
The modelling method has been revised across several areas: climate data requirements are clearer, solar heat gain coefficient assumptions for glazing are revised, and internal gains from lighting have been updated. HVAC modelling is no longer required at all, which is one less headache. In exchange, any deviation from default modelling assumptions now needs to be documented and justified.
Same mixed-use envelope flexibility as AS2, same wall R-value revision, same bathroom exemption for heated surfaces, same shift to internal dimensions for area calcs. Same swap from AS/NZS 4859.1 to the Building Product Specifications for insulation. Rest is reference and definition alignment plus cleanup, no performance impact.
{% hint style="info" %}
Grab H1 VM2 [here](https://www.building.govt.nz/assets/Uploads/building-code-compliance/h1-energy-efficiency/asvm/h1-energy-efficiency-vm2-second-edition.pdf)
{% endhint %}
The net effect is that both documents lean toward more flexibility and, arguably, an easier compliance path than their first editions. Not something you hear often about a Building Code update!
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