In Perth most houses are double brick but this one is timber and it didn’t cause a revolution

CASE STUDY: This small, simple energy efficient Perth home designed by architect Ben Caine wowed the market when it went to auction and it’s so energy efficient it didn’t even need solar panels.

When architect Ben Caine was designing a super high energy performance, timber framed home on a laneway block in coastal Perth, he was conscious of not creating another bespoke hard-to-replicate home built purely for “magazine fodder”.

“Good performance homes should be available to more people, not less,” the Leanhaus architect told The Green List.

Like all Ben’s high-performance designs, this two-bed, two bathroom, plus study home in Scarborough known as Abbetthaus is elegant in its simplicity.

And it’s not just a play to a minimalist aesthetic. There are so many benefits, Ben says of his preferred way of working. Cutting out unnecessary extras keeps costs down and it puts high performance, architecturally designed homes in reach of first homeowners with more modest budgets.

It looks like the market also appreciates where Ben’s coming from. His simple, comfort-driven design recently paid off with a record price for location and block size. More than 80 people came through on each of the two inspections.

Ben says there were many unhappy homebuyers who walked away empty handed. One of them even got in touch to see if he’d design a similar home for them.

Of course that’s in a “pretty hot” market where there’s an undersupply of housing, especially homes that are even “mildly environmental friendly”. In Perth, Ben says you’re lucky to even get the right orientation.

In Perth most new housing is double brick which means pretty poor thermal performance.

The industry’s been building this way for decades, changing nothing but the style since the 70s, Ben says. So most people who came to the auction were emerging from an uncomfortable, expensive winter in these double brick homes and could have been quite open to something different.

Passive House and passive solar design working together

Ben designed the Abbetthaus along certified Passive House lines. This is a highly energy efficient building method that “performs like a thermos” to stay comfortable all year round using very little energy. Best performance comes from combining the best of Passive House design with the best of passive solar design principles, such as north facing orientation to take advantage of the sun’s warmth in winter, Ben says.

“It’s nice to have those rays beaming in on your skin on a winter’s day, from a psychological perspective.”

It’s pretty well what his client had his heart set on – an ultra efficient, delightfully comfortable home – and it came with a 60-page briefing document, attached to a modest budget. A bit much for the first building designer engaged on the project, as it turned out.

Not for Ben.

He tackled the challenges head on and with considerable creativity. First, the site was not ideal. The laneway block is a tight 213 square metres, and it fronts a two-storey high wall on its north, casting a significant shadow just where you don’t want it.

Sticking to the budget also meant rooftop solar didn’t make it into the project. Interestingly because of the tiny annual energy consumption the payback period was deemed way too long anyway.

This meant the ideal orientation was compromised, so passive solar design alone was not going to cut it. The project needed the airtight membrane, high performance windows and mechanical ventilation system of Passive House to hit the brief.

Despite the shadowed northern boundary, Ben still managed to achieve north facing orientation by pulling the home further back on the site and leaving the shadowed space for an open carport, which conveniently doubles as a covered outdoor living area.

The main living area looks onto this extended courtyard, which has a small plunge pool to add a touch of luxury.

The smaller footprint kept costs down (but meant Ben had to be mindful not to let the spaces feel enclosed) and it freed up budget for the high-performance glazing and ventilation system.

Energy consumption so low the client skipped the solar panels

Because of its simplicity, Ben says the home was much more affordable than a similar architecturally designed home. Sticking to the budget also meant rooftop solar didn’t make it into the project. Interestingly, because of the tiny annual energy consumption, the payback period was deemed way too long anyway.

Timber, not brick

Ben’s use of timber is a bit unusual for brick-obsessed WA, but it’s what he prefers.

First, it’s sustainable because it’s a carbon sink, it’s renewable and recyclable, but it’s also well suited to Passive House and the team wanted to avoid steel, which is carbon intensive and slows down construction.

Timber, by contrast, is quick and easy to build with.

It’s also not so hard to source, despite typical building habits. Compared to other sustainable building materials, such as structurally insulated panels, for instance there are plenty of suppliers offering timber framing in WA.

“It provides the most versatility. It buffers you from the impacts of dealing with one or two suppliers.”

But in keeping with what the market is used to, the house ended up with a brick skin on the house facing the laneway.

The builder was up for the challenge

When Ben took on the challenging project, he wasn’t particularly familiar with the Passive House standard, and it was actually the builder, Chris Evans from Passiv Building Co, who suggested the technical building method.

Ben noted that given the attention to detail and planning that goes into a home like this, it really helped to have the vote of confidence from the builder delivering the home.

“You have to be passionate about it to do it well.”

Other people on the project:

• Project Manager/Owner: Jason Edmiston
• Structural Engineer: John Velios, Total Structural Solutions
• Interior Designer: Lara Staunton. LAHAUS Creative Studio
• Landscape Design: Mon Palmer, Slightly Garden Obsessed
• Passivhaus Certifier: Clare Parry, Grün Consulting