How can a 19th-century worker's cottage be adapted for contemporary family living while remaining resilient to the challenges of the 21st century?

To address this question, 39S House reimagines a traditional Brisbane worker’s cottage with a focus on energy efficiency, carbon reduction, and climate resilience. Located in Petrie Terrace, the house originally suffered from poor thermal performance, harsh western sun exposure, and constant traffic noise. Instead of raising the house or extending at the rear—common solutions in Queensland—the design reorients the main living spaces, creating a new two-storey extension to the west. This shields the home from heat and noise while optimising northern light and ventilation.

Sustainability is embedded in every aspect of the design. The home prioritises low-embodied-carbon materials, including lightweight timber framing instead of concrete and reverse brick veneer walls made from reclaimed bricks to provide thermal mass. Locally sourced blackbutt timber is used for floors, doors, and joinery, while kitchen cabinets, downlights, and glazing from the original house are repurposed, reducing material waste.

Originally designed as a 9.8-star NatHERS home, the project was refined to 7.7 stars to achieve the lowest whole-life carbon outcome. A detailed analysis showed that the embodied carbon of high-performance double glazing outweighed its operational benefits, leading to a shift to high-quality single glazing in timber frames. This decision ensured that the house minimised emissions over its entire lifespan while maintaining strong thermal performance.

The home is entirely powered by renewable energy, with a rooftop PV system exporting more electricity than it consumes. All-electric appliances eliminate fossil fuel use, while careful refrigerant selection reduces environmental impact. R6 ceiling batts and earthwool space blankets provide additional insulation, improving year-round comfort. Water harvesting and low-U-value glazing further enhance efficiency.

The design also fosters indoor-outdoor connectivity. By pulling the mass of the house closer to the street, a lush northern garden is created, linking to a stepped living and dining area that acts as a semi-outdoor space, improving natural ventilation. Deep roof overhangs, timber screens, and operable openings enhance passive cooling, eliminating the need for air conditioning.

Balancing energy efficiency, embodied carbon reduction, and climate resilience, 39S House proves that older homes can be reimagined to exceed sustainability benchmarks while maintaining Queensland’s timber housing character. The result is a home that significantly lowers both running costs and environmental impact while offering a model for sustainable refurbishment.