How H6V2 works, in three steps.

Two models of the same house, and why the comparison can change which upgrades a design needs.

We model your house as designed.
We model a reference version of the same house, built to the NCC’s own Deemed-to-Satisfy specifications.
If your design needs no more heating and no more cooling than the reference, it meets the Performance Requirement, H6P1.

Same floor plan, same window sizes and positions, same thermostat settings and occupancy. What can differ is the insulation, the glazing performance and the shading.

That is why it can cost less: the design is upgraded where it needs to be, not to reach a star band. And that is why it sometimes doesn’t, which is what the Pathway Check is for.

SourcesNCC 2022 Volume Two, H6V2(1)–(5) and H6P1.

More insights

DesignThe energy pathway is a design decisionChoose the route at concept stage, and the glazing and layout you worked for are more likely to survive.
Building physicsA rating checks the design, not the buildEvery compliance route assesses the drawings. Checking the finished house takes a few hours.
Wall systemsOctober 2026Double brick to frame: what happens to the rating?Three things change in the wall at once, and in Perth the mass often counts.

All insights

Pathway Check

Which route suits your design?

Send your plans and we’ll compare the routes, including when the answer is NatHERS.

Request a Pathway Check