This Verification Method compares the greenhouse gas emissions of a proposed building to that of a reference building which is based on the Deemed-to-Satisfy Provisions. If the greenhouse gas emissions of the proposed building do not exceed that of the reference building, compliance with J1P1 is achieved.

Through this modelling process, it must be demonstrated that the Performance Solution is equivalent to, or better than, the Deemed-to-Satisfy Provisions. This equivalency is also one of the Assessment Methods recognised in the NCC.

J1V3 includes provisions in J1V3(1)(a)(ii) which are designed to protect the thermal performance of the building’s envelope from “trading” off its performance with that of the building services.

The steps to using this Verification Method are:

• Determine the annual greenhouse gas emissions allowance by modelling a reference building, i.e. a Deemed-to- Satisfy complying building based on the criteria in S34C2, S34C3 and S34C4.
• Calculate the theoretical annual greenhouse gas emissions of the proposed Performance Solution u sing the criteria in S34C3 and S34C4.
• Calculate the theoretical annual greenhouse gas emissions of the proposed Performance Solution, with the services modelled as if they were the same as that of the reference building. This tests the performance of the facade.
• Compare the theoretical annual greenhouse gas emissions calculated in steps 2 and 3 to the annual greenhouse gas emissions allowance calculated in step 1 to ensure that in both cases, the annual greenhouse gas emissions are not more than that allowed.

The same software must be used in all modelling runs.

J1V3 can be used for all buildings using the occupancy profiles and other assumptions provided in Specifications 34 and 35.

Figure J1V3 illustrates how J1V3 can be used to assess different Performance Solutions.