WGV – WA’s First One Planet Community
- Client: LandCorp
- Location: White Gum Valley, Western Australia
- Date: July 2019
White Gum Valley (WGV) is one of LandCorp’s ‘Innovation through Demonstration’ projects. WGV is the focus of a four year ‘living laboratory’ research program with the Cooperative Research Centre for Low Carbon Living to monitor the performance of the homes located within the estate and to share its findings with the wider community and industry. The project demonstrates the very best in modern, sustainable design and has created a community where it is easy and affordable for people to live in a way that makes smart use of the earth’s resources. The development is certified by the One Planet Living framework.
The site is located 3kms from the Fremantle city centre in the suburb of White Gum Valley, the new residential estate is sympathetic to the community and environmental aspirations of the surrounding suburb. The north boundary faces the Fremantle golf course and Royal Fremantle golf club and two recreational parks, Booyeembara Park and Valley Park, are located just short walks away.
eTool was contracted to conduct the ‘as-designed’ life cycle assessment on 5 of the completed and occupied residential dwellings within the WGV project.
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.
The LCAs were conducted based on the usual eTool methodology which goes beyond the EN15978 scope by including modules B6+ (non-integrated energy). The assessment includes all the upstream and downstream processes needed to establish and maintain the primary function of the buildings, from the acquisition of raw materials to their disposal or to the point where materials exit the system boundary either during or at the end of the buildings’ life cycle.
The grids used for operational energy and water use were the WA SWIS electricity grid, WA distributed gas grid, WA water supply & treatment grids.
The five assessments were conducted by Robin Campbell and Fei Ngeow from eTool and internally certified. Please contact eTool for more information on LCAs.