Breaking new ground – certified passive house takes out 2021 HIA Australian GreenSmart Home

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After more than 30 years of building sustainable homes, Lachie and Beth Gales and the team at their Wangaratta-based family business, Ovens and King Builders, are used to breaking fresh ground.

Their latest home — a small ‘passive house’ in Beechworth in north-east Victoria — was their boldest step yet, requiring them to meet what is arguably the toughest voluntary building standard in the world.

To be certified, a passive house must be so highly energy efficient that it achieves a comfortable internal temperature year-round with little to no heating or cooling requirements.

But with a strong commitment to training, thoughtful design and quality workmanship, the team succeeded in building a phenomenal, fully certified passive house that requires zero heating or cooling and recently cleaned up at this year’s HIA GreenSmart Awards, taking out the highest accolade – 2021 HIA Australian GreenSmart Home.

“I’ve been in the industry for a long time and it’s exciting to be involved in something that reflects what we want to do in terms of quality construction, as well as reflecting what we want to do for our community. We want to build houses that are part of the solution,” Lachie says.

The build

The older couple that owns the small, 234-square metre Beechworth block had a lovely home but wanted to downsize as a sensible step for their later years. Being community-minded, they also wanted to show what could be done.

“They wanted to show people a bit of leadership and with these kinds of constructions that’s a common theme — people want to have those lighthouse moments where they’re guiding people into ‘look this is what can be done’,” Lachie says.

The owners engaged an architect who introduced them to Ovens and King Builders who then took on the job as a design and construct. The team engaged a passive house consultant in Beechworth and together they worked through all technical details necessary for the build to succeed.

With Lachie’s eldest son Jim at the helm as senior supervisor, the company worked through several challenges, including those associated with a small block size and the installation of heavy windows.

“It was the first time we’d used triple glazed timber aluminium composites, from LogikHaus. Triple glazed windows have got their challenges just in weight,” Lachie says.

He says passive house demands quality construction from the first shovel in the ground, so you mustn’t get any aspects of the thermal envelope or the airtight membrane wrong.

“That was actually liberating for us because we’ve always had this focus on quality construction and here we’ve actually got a form of construction that validates what you want to do.”

The pay off

Lachie is in close touch with the owners of the Beechworth passive house — which achieved a 8.9-star rating and uses less than 15 kWh of electricity per year — and says it has delivered on its promise.

“Beechworth is a colder climate, you’ll get frosts up here and on the same day you’ll get sunshine. These people get up every day in the winter and its 16 to 18 degrees in the house, and that’s without any form of heating or cooling. The house works, so the comfort levels are inherent. And you can imagine what it does to the energy costs,” he says.

To help achieve the thermal properties of the house, Bradford PIR Boards (previously known as Xtratherm) were supplied by Dahlsens and used as insulation.  PIR Boards are a high-performance building insulation product in a slim board form, made from an advanced foam sandwiched between two layers of reflective facing, PIR Boards can be used to create continuous thermal break between the external walls and the house frame.

The future is passive 

Lachie, who has another passive house build underway in Bright, says it is the second year in a row that the HIA award has gone to a passive house and believes it is a subject we will hear more about in the building industry.

“Sustainable construction is inevitable because we cannot continue to build houses in the way that we have in the past,” he says.

“The things we’ve learned from the Beechworth house sets us on the right path. We need to get on board sooner rather than later because the people we’re training now will be expected to deliver houses of a much higher standard in their lifetimes.

One of the joys for me at this stage of my career is to see these younger people really engage with what we’re doing here. We’ve done the training and set up the protocols around Passive House, but the hands-on work was done by a young team. They really engaged with it and are really proud of the result.

So it’s a joy to see these younger people start their careers working on these kind of houses, because that’ll become the norm for them. For older builders like me, it’s on the cutting edge. Our role is in providing some leadership to the people that we’re employing and training and mentoring, as this will become their norm. And as a community that’s where we need to go.”

Dahlsens congratulates Lachie, Beth, Jim and the team at Ovens and King Builders for taking out the 2021 HIA Australian GreenSmart Home, and paving the way for future generations of passive homes.  We’re incredibly proud to work with builders like you, and helping to bring projects to life right across Victoria and New South Wales.