Site A is a double story 2 bedroom dwelling with hydronic in-floor heating, 6.5kW solar PV system & ceiling fans. It is also the largest dwelling among the 5 residences assessed. The dwelling mostly uses SIP panels in its roof and wall construction along with recycled brick feature walls. The dwelling only achieves 54% savings against the AU benchmark compared to the other residences assessed due to the higher operational energy usage from the electric cooktop, lower thermal performance and lower occupancy rate/m2.

Site B is a freestanding single-family dwelling with 2 bedrooms and 2 bathrooms. The house is constructed from insulated timber stud-frame internal and external walls with double-glazed UPVC windows and a colorbond steel roof. This house performed well because of the light weight, timber construction, the high NatHERS rating of 8.4 stars, the UPVC windows and the 5.6kW solar PV system. The main feature that worked against this home was that it was a detached single-family dwelling, as this has impacted the estimated design service life due to redevelopment pressures.

Site C is a freestanding single-family dwelling with 5 bedrooms and 3 bathrooms. The house is constructed with foil-insulated, rendered, double brick external walls, single brick, rendered, internal walls, with single-glazed aluminium windows and a colorbond steel roof. This home had the lowest NatHERS rating of the 5 homes assessed at 7.1 stars. It also had the
shortest estimated design service life due to redevelopment pressures, due to being a detached single-family home.
Factors that worked in this home’s favour were that it has an air-source heat-pump HWS, LED lighting throughout and its 3.85kW solar PV system.

Site D is a 2-story triplex consisting of three single bedroom dwellings. eTool was able to be involved at the early design stage of the project and thus influence some changes which helped improve the environmental impact of an already decent building. Some of the recommendations they accepted were to replace the elevated concrete floor to a timber framed system, specify 30% blast furnace slag concrete slab on ground, install building integrated energy monitoring systems with comparative feedback functionality for the 3 dwelings, low flow shower heads, gas instant HWS and a gas cooktop. These improvement strategies on top of the 9kW solar PV with battery storage system helped the building achieve the lowest environmental rating per occupant/year amongst the 5 dwellings eventhough the thermal performance isn’t the best.

Site E is a semi-detached two-family residence with a total of 3 bedrooms and 2 bathrooms. The house was constructed with recycled rubble, rammed earth for the ground floor external walls and Structural Insulated Panels (SIPs) for the upper floor walls. The windows were double-glazed aluminium with a thermal break and the roof was framed with cross-laminated timber and clad with colorbond steel. The house also made use of low impact cork and rubber as floor coverings. This house performed well because of the low embodied energy of its construction, its high predicted service life, due to it being semi-detached and the 6.21kW solar PV system. The mid-range NatHERS rating and the induction cooktop were the main items that worked against this house.