by Sally-Ann Jones & Jessica Rule
The West Australian on May 16, 2016, 2:49 pm
PassivHaus build new to WA
Consortium Builders has been working with leading architects and designers for the past 15 years to create about four top-drawer homes annually.
Andrew Abercromby, a civil/environmental engineer, and builder Mark Swann formed Consortium Builders in 2000 to build the multi award-winning Piney Lakes Environmental Education Centre for the City of Melville.
Last year a new client sought them out for an exciting project at the leading edge of modern, energy-efficient design and construction – one that could be the start of a WA building revolution.
When approached by designer Roger Joyner to build a high-comfort, low-energy beach house in Cottesloe for a local surgeon “we jumped at the chance”, Mr Abercromby said.
The client’s twin brother heads the Canadian PassivHaus Institute and encouraged his sibling to build the first certified PassivHaus in WA, putting his new home – and his designer and builder – in the local vanguard of a movement that is sweeping the world.
The new home resides on a 440sqm block between two Cottesloe homes that were built before 1920. The owner’s brief called for a lot of accommodation to be created on a relatively small footprint – “…a beach house that would fit in with the streetscape and become WA’s first PassivHaus – a German ultra-low energy, high-comfort design,” Mr Abercromby said. “This resulted in three storeys, each with split levels front-to-back, and a roof terrace – a total of seven levels.”
There are six bedrooms, four bathrooms, a library, study, home theatre, a two-car basement garage and storeroom, a roof terrace and a six-level, glass-sided lift (imported from Sweden). The roof terrace, lift and stairs act as a light well bringing a sense of openness into the heart of the home. The teenagers’ bedrooms are on the upper level and share a spacious common/activity room – all with raked ceilings. A rear balcony off the master bedroom faces north and overlooks the pool and outdoor entertaining area.
The kitchen has a linear layout with stainless steel bench tops, Miele appliances and a scullery/laundry. An island bench with brushed granite top features a Bora induction hob with central downdraught extractor lit by a pair of nautical pendant lights.
PassivHaus was initially created for cold European conditions, but the concept has since been applied many times around the world in all climates. Almost 50,000 houses have been certified PassivHaus worldwide. Mr Abercromby said the keys to a high-comfort, low-energy home were good insulation and tight construction.
“If these are built into the fabric of the home then a heat recovery ventilation system (or HRV) can be installed,” he said. “Fresh air is constantly ducted into all the living areas and extracted from the kitchens and bathrooms. “Up to 90 per cent of the energy of the outgoing air is used to heat or cool the fresh, incoming air via an HRV heat exchanger.”
“The cost of heating or cooling required to maintain the ideal indoor temperature all year round can be as little as 10 per cent of a normal home. The HRV is driven by only two 30W fans running 24/7 which together cost less than $150 a year to run.” The European-style, double-glazed tilt-and-turn windows and doors can be opened anytime to let in the sea breeze, while the ventilation system maintains comfort all year round.
According to Mr Abercromby, the most challenging aspect of trying to meet the PassivHaus standard in Australia was that ’tight construction’ was an almost completely unknown concept in the local building industry… “so we imported a German specialist to join our construction team for six months!”
“The typical Australian house leaks 15-25 volumes of air an hour in a standard blower test; the European standard is less than 1.5 and the PassivHaus standard is 0.6,” Mr Abercromby said.
“The Cottesloe house measured 0.25 on its first test, making it at least 50 times better than the Australian average. We had an independent expert come over from New Zealand to conduct the test and he declared our result an Australian and New Zealand record.”
PassivHaus Cottesloe has also broken building-time records. While the complex in-ground works took four months to construct, the upper five levels were erected from ground level to lock-up in only seven weeks thanks to Consortium Builders’ focus on rapid construction methods.
“Above ground, all the walls and the roof structure were constructed using SIPS (Structural Insulated Panel System). We erected the walls, inter-floors and the roof of the five upper levels in seven weeks with a team of six carpenters,” Mr Abercromby said.
“Because our team was completely in control of accuracy, we were able to have the uPVC windows and doors custom-manufactured while we were putting up the main structure – and mostly installed before we had the roof on.”
The roof, gutters and downpipes are Colorbond Surfmist, with Linea weatherboard exterior painted to match. The driveway walls to the basement and the boundary walls are painted 150 per cent Surfmist. Windows, doors and surrounds are white. The effect is in keeping with the streetscape and the nearby beach.