This dwelling achieved a 4.5 Star Rating using the NatHERS assessment method. The project required the following adjustments to achieve a minimum 6 star compliance:
- Insulate all ground floor external cavity walls (approx. 127m2)
- R4 ceiling insulation
- Upgrade Retreat and Hub glazing (excl. 25×15 slider) to Low E Clear glass (approx. 5m2)
- Insulate upper floor roof cover with Anticon 55 (approx.. 80m2)
When Structerre assessed this dwelling through the VURB method the following heating and cooling energy loads applied:
- Reference Heating: 60.3 MJ/m2 Cooling: 30.4 MJ/m2
- Proposed Heating: 43.0 MJ/m2 Cooling: 14.9 MJ/m2
As the proposed house had heating and cooling energy loads which were equal to or less than the reference building, the proposed building was deemed compliant through V2.6.2.2 NCC 2013.
The proposed building was compliant based on the builder’s standard specification:
- R3.5 to ceilings
- Generic single clear glass – Value 6.57 SHGC 0.74
- Sealed exhaust fans
No cavity insulation or upgraded glazing was required for compliance.
This assessment method has been carried out in accordance with the V2.6.2.2 (a), (b), (c), (d) & (e) requirements by a Structerre qualified person using NatHERS accredited software.
Even though this project is not a 6 star energy efficient dwelling, it will still meet BCA V2.6.2.2 energy compliance. The reduced construction costs are based on 127m2 x $15/m2 cavity insulation, 80m2 x $10/m2 Anticon 55 and 5m2 x $150/m2 Low E Clear glazing.
This equates to a potential cost saving of $3,455
