Single Dwelling or Multiple Dwellings in terms of NatHERS Assessment

Region: All States

Assessor Question:

We have a project that has been classified as “Class 1a - one or more buildings, which together form a single dwelling’’

The project is to accommodate an extended family and has a main residence with several non-attached buildings, some with no kitchen.

My questions are: 

1. Can we complete this as a single NatHERS assessment as the buildings are not attached? 

2. Should we just complete the main house (Centre building )as a NatHERS assessment and the rest of the outbuildings as DTS?

3. Should each building be a separate NatHERS? The only issue there are two single storey dwellings that do not contain a kitchen.

TechLink Response:

• A single dwelling with 23 double bedrooms and parking for 20 cars would at face value appear to be a bit of a stretch of interpretation of the rules applying to classification of building in the NCC.
• The layout is more clearly identifiable as a number of dwellings but without all the kitchens being delineated.
• It may be prudent to clarify how many children or how big the extended family is being accommodated.
• The RBS will have to respond to questions about the actual operation of the building once completed if a permit is issued for a single dwelling and it is actually run as a hotel or a number of townhouses rather than a single house. 
• That said, one NatHERS DtS rating for the center portion containing the kitchen and Elemental DtS assessment for the rest would be possible for a Class 1 dwelling with core and satellite portions.