39S House 2025

39S House

39S House: A Timber Cottage Reimagined for a Low-Carbon Future

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 responsiveness. Instead of raising or extending at the rear, the house is reoriented to optimise northern light and cooling breezes while blocking harsh western sun and highway noise. A new two-storey extension enhances thermal comfort and completes the streetscape.

Sustainability is embedded in every aspect of the design. The home prioritises low-embodied-carbon materials, including lightweight timber framing and reclaimed bricks for reverse brick veneer walls, adding thermal mass. Blackbutt timber, sourced from responsibly managed forests, is used for floors, doors, and joinery. Kitchen cabinets, downlights, and glazing from the original house are repurposed to reduce material waste. High-quality single glazing in custom timber frames balances energy efficiency with material impact.

Originally designed as a 9.8-star NatHERS home, the project was redesigned to 7.7 stars to achieve the lowest whole-life carbon outcome. The embodied carbon of high-performance glazing outweighed its operational benefits, leading to a switch to high-quality single glazing.

Powered entirely by renewable energy, the house features a rooftop PV system that exports more electricity than it consumes. All-electric appliances eliminate fossil fuel use, and carefully selected refrigerants minimise environmental impact. Extensive insulation—including R6 ceiling batts—ensures year-round comfort.

A stepped living and dining area integrates with private outdoor gardens, improving natural ventilation. Water harvesting and low-U-value glazing reduce resource consumption, while strategic massing shields against noise and heat.

39S House proves that older homes can exceed sustainability benchmarks, reducing both running costs and environmental impact while preserving Queensland’s timber housing character.