Complinace using NatHERS thermal report with Elemental WoH

State: All

Asessor Query:

Does DMN have information providing something definitive that I can say to Certifier who questions the validity of a compliance pathway to adopts a NatHERS certificate for thermal assessment with Elemental Whole of Home portion of the assessment? 

TechLink Respons:

• H6D1 sets the understanding of requirements for Deemed to Satisfy procedures leading to the need to comply with H6D2.
• The explanatory information to this part states without equivocation that there are 2 Deemed to Satisfy pathways to confirm compliance with the necessary Performance Requirements, being NatHER DtS or Elemental DtS.
• H6P1 for the building fabric can use a NatHERS house energy rating and S42C4(1) or complying with the Elemental items in Parts 13.2, 13.3, 13.4, and 13.5.
• H6P2 for energy use is a separate exercise which may use the Whole of Home module of the NatHERS software and S42C4 or with the Elemental items in Parts 13.6 and 13.7
• It is acceptable to use NatHERS calculations for both the Building Fabric and the Energy Use.
• It is also acceptable to use the Elemental provisions for both the Building Fabric and the Energy Use.
• It is also acceptable to use a NatHERS assessment for the Building Fabric with an Elemental assessment for the Energy Use.
• It is not possible to use a NatHERS assessment for the Energy Use without using NatHERS for the Building Fabric.
• The NatHERS Certificate for building fabric will include the statement that Whole of Home is not included in the Certificate if the Whole of Home module has not been used for Energy Use. This provides the prompt that Energy Use compliance will need to be demonstrated with an Elemental assessment or a Performance Solution or Expert Opinion.
• The ABCB Whole of Home Calculator is an accepted method of demonstrating Elemental Deemed to Satisfy compliance of Energy Use standards.
• It is acceptable to use a NatHERS assessment for Building Fabric alongside an ABCB Calculator for Energy use.
• This is in fact the Design Matters National Assessor Accreditation Organisation recommended approach for FirstRate 5 users at the moment while the data entry for Whole of Home attributes must be redone whenever the Building Fabric calculation is rerun.