• Adam Clarke

Section J, BASIX and NATHERS Compliance

Energy Assessments for Class 3 Group Homes and Class 1 multi-unit developments

GROUP HOMES - We have found in recent periods that some certifying authorities are not understanding the requirements around class 3 group home energy compliance.

In some instances, the energy assessment has solely been completed (in NSW) as a BASIX and NatHERS assessment.

The NCC states that a Class 3 Group home must demonstrate compliance against the NCC Section J. What needs to be taken into account with this type of assessment is the occupation use. A Class 3 building assumes that the occupants are transient and not occupying the building during the day. As seen on the thermostat settings below such as Occupancy, Lighting, Equipment, and HVAC are switched off during the day from 11am – 4pm.


Energy Assessments for Class 3 Group Homes and Class 1 multi-unit developments

This would be the case for a buildings use such as a backpackers or hostel, Motel or hotel, where the occupants would not be spending time in a room during the day and would only be using the space at night for sleeping.

A Group home would likely have the occupants occupying the building for long periods of time both day and night. The occupant settings for this would be similar to that of a class 1 or 2 type building. Additionally, the dwelling is designed to fit in with the local design environment. Adjacent building shading, window ventilation, roof colours and window colours would all come into place for the occupant’s thermal comfort.

The assess a class 3 group home strictly under the section J provisions may not meet the intent of the NCC class 3 provisions. An Energy design consultant would understand this and request a meeting with the design team and building consultant to assess the best pathway of compliance under the NCC. If it is agreed that the thermal performance of a class 3 group home would function thermally more like a class 1 or 2 building the Energy Consultant would develop a Performance Solution to demonstrate the compliance pathway.

This performance solution should show

  1. The classification of the dwelling

  2. The pathway required to achieve thermal compliance.

  3. Demonstrate the reason why this dwelling cannot achieve compliance using the specified thermal assessment pathway

  4. Show what system is going to be used to achieve compliance

  5. Outline the provisions to certify compliance under this alternative solution


10 Star Building assessments have provided many of these performance solutions for our clients for Class 3 group homes.


BASIX Compliance for Multiunit Developments.

We have found in NSW that the energy compliance pathway for duplexes and townhouses has not been followed according to the BASIX thermal protocol.

A single dwelling in BASIX is a dwelling that is on 1 lot of land and has been subdivided accordingly. Each dwelling thereafter is under a Torrens title.

In some cases, we have found that a BASIX certificate for a Duplex or townhouse, has been developed using 2 separate individual BASIX certificates as single dwellings. BASIX DIY Method for single stand-alone dwellings does not take into account the effects of adjoining neighboring properties. It assumes that all walls have impact from the external environment. High density developments have different heating and cooling loads requirements and should be assessed by an accredited energy assessor.

BASIX requires the simulation method to be used in cases such as these which is the only way adjoining dwellings can be assessed correctly. NatHERS (nation wide housing energy rating system) has approved software to analyze this and provide adjusted heating and cooling loads to be imputed into BASIX.

To ensure your development application is submitted using the correct pathway for compliance, 10 Star Building Assessments are familiar with these methods and are quality controlled through the accrediting organization ABSA – Australian Building and Sustainability Association.