JV3 or Deemed-to-Satisfy: which Section J route?

Two ways to meet the same requirement.

Under Part A2 of the NCC, Performance Requirements are met by a Deemed-to-Satisfy Solution (A2G3), a Performance Solution (A2G2), or a combination of the two (A2G4). For energy efficiency, the requirement in question is J1P1.

Deemed-to-Satisfy: follow the rules element by element.

A2G3 says a solution that complies with the Deemed-to-Satisfy Provisions is deemed to have met the Performance Requirements. For Section J, J2D1 lists the clauses, and J2D2 says a Class 3 to 9 building meets J1P1 by complying with Parts J4 to J8, J9D3 and J9D5(2) to (4).

Each element is checked against its own limit: roof and wall R-Values, glazing through Specification 37 for J4D6, sealing, plant efficiency, lighting power and controls. No whole-building model is needed.

J1V3: model the building against a reference.

J1V3, titled verification using a reference building, is a Verification Method, so it is used as part of a Performance Solution. It was JV3 in NCC 2019, became J1V3 in NCC 2022 and keeps that number in NCC 2025.

The proposed building is modelled and compared with a reference building based on the Deemed-to-Satisfy Provisions. Under NCC 2025 J1V3, compliance needs all of the following:

1. Annual greenhouse gas emissions of the proposed building not more than 97% of the reference building's, modelled with the proposed services.
2. With the reference building's services, the proposed building's emissions not more than the reference's, which tests the envelope on its own.
3. Thermal comfort and zone load limits set out in the clause, which vary by climate zone.
4. The additional requirements in Specification 33.
5. A calculation method complying with ANSI/ASHRAE Standard 140, Specification 34 and Specification 48.

What changed between 2022 and 2025.

Under NCC 2022, J1V3 asked for emissions not more than the reference building's. NCC 2025 adds a 3% margin and adopts new weather files, as the ABCB summarises.

When each route makes sense.

Deemed-to-Satisfy suits most jobs

Fitouts, warehouses, small offices and shops where the elements can meet their limits. It is quicker to document and easier for the building surveyor to check.

J1V3 earns its time when one element cannot pass

A heavily glazed facade or a design the architect will not change. Modelling can show the building as a whole performs, letting better plant or lighting carry a facade that fails on its own.

The trade-off

J1V3 needs full energy modelling, the Performance Solution process under A2G2, and a building surveyor willing to accept it. It is a bigger job than Deemed-to-Satisfy.

We write Deemed-to-Satisfy Section J reports. Where a design cannot pass element by element, we say so early, so the team can choose between a specification change and modelling.

Sources: NCC 2025 Volume One, Part A2, Part J1, Part J2 and Specification 37; NCC 2022 Part J1; ABCB, NCC 2025 commercial energy efficiency changes and NCC 2022 lexicon. General information, not an assessment of any particular site.

The ones that come up every week.

Not sure your design passes Deemed-to-Satisfy? Send the plans.

Section J reports for Class 3 and 5 to 9 buildings in Victoria. Send the drawings and window schedule, and a quote comes straight back.

Common questions