Sustainable House Day 2026: Come on in

Once a year, hundreds of people across Australia open their doors and share what they’ve learned about making their homes more comfortable, affordable and climate-ready.

From beautifully designed architectural homes to carefully retrofitted weatherboard cottages and efficient apartments, these are real places with real stories. Not perfect homes, but lived-in ones – where neighbours share what worked, and what they’d do differently. Neighbours inspiring neighbours, one open door at a time.

The four homes featured here are just a glimpse of the many that were on display for Sustainable House Day 2026. You can explore these and many more on the website: sustainablehouseday.com

The Back House

“It’s a small building, but it carries years of thinking,” Kulja Coulston – former Sanctuary editor – says of the self-contained studio she and partner Andy recently completed in their suburban Melbourne backyard. “We talked about adding a small second dwelling for nearly a decade – our home suited young kids, but we knew it wouldn’t work as well once they were older.” When updates to the legislation removed the need for a planning permit for a self-contained garden unit, they knew the time was right.

“The brief was for a space that could accommodate two adults, with areas for study, relaxing, cooking and music making,” says building designer Elizabeth Wheeler. She gently steered Andrew and Kulja away from their tiny-house instincts, encouraging them to increase the footprint to around 38 square metres. “That decision allowed for a living area with a raked ceiling and a generous separate bedroom, giving our adult children the ability to continue living independently at home,” says Kulja. “It also future-proofed the building in case we ever choose to live there ourselves.”

Although site overlays meant they couldn’t tuck the little house in the far corner of the block as planned, in the end they have actually gained garden space thanks to the removal of an old shed, a big trampoline and an overgrown hedge. “Many urban blocks have poorly utilised space that could be leveraged to increase density,” says Elizabeth. “This ‘studio’ feels like a proper house, has no negative effects on neighbours, and was achieved despite several very significant site constraints. As proof of concept, it doesn’t get any better.”

The owner-built project was “deeply collaborative”, Kulja says, with a lot of valuable assistance from her dad Mick, who’s skilled in working with both new and reclaimed materials. They chose lightweight construction, using a Mega Anchor foundation system and an AlphaFloor concrete-panel floor to provide thermal mass beneath reclaimed messmate floorboards. Material reuse is woven throughout: salvaged bridge timbers were crafted into kitchen cabinetry, doors from a 1920s bungalow were repurposed, and much of the furniture was sourced secondhand, sitting comfortably alongside new energy-efficient appliances.

380 Albert

Sustainability professional Shaun Tompkins was always going to do what he could to make his first home as energy-efficient and sustainable as possible. Four years ago, he bought a one-bedroom apartment in a typical 1960s ‘six-pack’ block of flats in Melbourne’s Brunswick West. “Because the apartment is on the top level and north-west facing, it was a hotbox,” he says. “It had single-glazed aluminium-framed windows, no external shade, and no insulation in the ceiling cavity!”

He began planning upgrades that would improve the apartment’s thermal comfort and liveability, and be achievable largely DIY and on a budget. “One big intervention was removing the plaster ceiling and installing R3.5 insulation batts, and using Kingspan Kooltherm K17 insulated plasterboard panels to line the north- and west-facing walls,” he says.

Shaun replaced the cheap carpet with cork flooring. He installed a new, slightly reconfigured kitchen made from IKEA cabinets with custom plywood doors and a reclaimed timber benchtop, and added a two-zone induction cooktop, which he says “has been perfectly fine for my needs, and heats water quicker than my kettle”.

Secondhand flatpack wardrobes along with a custom curved plywood bookshelf add useful storage to the bedroom and its study corner, and blockout blinds and timber Venetians on the windows allow Shaun to regulate solar heat gain and glare.

All up, Shaun spent around $22,000. “I saved on costs by doing almost everything myself,” he says. He also made the most of a membership at his local tool library, borrowing just about all the equipment he needed.

He’s very pleased with the result. “By introducing warmer tones and a splash of colour with the kitchen cabinets, it feels like a home. It’s super cosy, and gets a unique little view of Brunswick West from the third level – including great sunsets.”

Cygnet Earthship

Motivated by a “deep-seated desire to live a sustainable, self-sufficient lifestyle connected to a community” – and priced out of the Melbourne property market – Kate and Matt made the move to the small Tasmanian town of Cygnet and embarked on an ambitious owner-build project. Their new home is an Earthship, designed for passive thermal performance in the cold climate without the need for active heating or cooling.

It looks a little different from your average Earthship, with rammed earth walls replacing the typical earth-filled recycled tyre construction and giving the house clean, elegant lines. Key features remain, however, like internal cob walls and recycled bottle-brick details. And, of course, the greenhouse along the front of the house that traps the sun’s warmth and helps regulate the internal temperature. Greywater is recycled here to grow a surprising variety of food plants year-round, and the space performs incredibly well, says Kate. “In Tasmania, people think you’re crazy not to have a fireplace, but we didn’t install one and haven’t missed it. The walls act as massive thermal batteries, soaking up the sun and keeping us cosy even when it’s freezing outside, and we have no heating bills. It’s transformed our lifestyle – instead of being slaves to the wood pile or stressing over electricity prices, we live in a house that regulates itself.”

Although the build was a lot tougher and took much longer than the couple had anticipated, they are delighted with their finished home. “We’ve proven you can have a high-performance, climate-ready home that’s incredibly comfortable and beautiful,” says Kate. They are now nearly finished building a matching house for Matt’s dad next door, and have their eye on an even bigger prize: a cohousing community of Earthships allowing five households to share the large parcel of land, with communal facilities, gardens and an orchard. “The micro-village we’re planning will balance private living with social and economic resilience,” Kate says.

Mylor Bush Retreat

When James and Elizabeth set out to add a small extension to their much-loved mudbrick home in the Adelaide Hills, a top priority was to use low-impact, sustainable materials wherever possible. “We have always cared about treading lightly on the earth and wanted our house to demonstrate this,” says James. “We are trying to show our children how even small positive changes can make a difference.”

The project involved the addition of two bedrooms connected to the main house by a short set of steps. The existing bathrooms were upgraded, and a bedroom converted to a ‘snug’ for extra, flexible living space for the family. Windows were also upgraded to double glazing, the roof replaced with a new, light-coloured one to reflect heat, and bulk ceiling insulation added.

The extension is reverse brick veneer with a ventilated facade that’s clad with ‘shou-sugi-ban’ charred timber. It features a raked roof and high, shaded north-facing windows to admit winter sunlight. “We used recycled bricks, reclaimed timber for reveals, architraves and stairs, locally made terracotta tiles for bedroom floors, and breathable, natural paint,” James explains.

The addition has allowed the four children to have their own bedrooms, which James reports has changed the family dynamic in a positive way. “The extension is fantastic and performs extremely well in all seasons,” he goes on. “Working with people who are passionate about sustainability – like our builder Zemon and his team from SustainaBuilding – helps drive innovation and brings an energy that rubs off in everything we did.”