The New Zealand Green Building Council (NZGBC) advises that for a contiguous multi-unit building (i.e. apartments or townhouses) assessed under Homestar, each dwelling typology within the project is generally required to individually meet the minimum standards for HC1 (Winter Comfort), HC2 (Summer comfort), and EF4 (Energy Use).

However, in order to account for practical design limitations while maintaining overall performance consistency across the building NZGBC will allow a percentage of dwellings to exceed the relevant thresholds for a particular Star rating provided that any individual variant of the typology does not exceed 20% of the credit requirements for HC1 & EF4 and absolutely no more than 10% overheating (10% total annual hours above 25degC) for HC2.

The percentage of dwellings that exceed the credit thresholds should not exceed 20% of the total units within a contiguous building.

The onus will be on the project team to show that remaining dwellings (i.e. the next worst case variants) do meet the relevant thresholds.

Note that this Technical Clarification does not apply to standalone dwellings or averaging of units across multiple buildings.