Sustainable Revamp for Iconic Coastal Mollymook Site

In the seaside town of Mollymook, a once-whimsical wayfinding landmark for local surfers has been reimagined as a cutting-edge example of sustainable design.

GALLERY

The “Cake House,” known for its distinctive kite-like geometry, has been transformed by Sydney-based Alexander Symes Architects into a high-performance, all-electric residence that balances architectural character with climate resilience.

Rather than altering the original footprint, the practice embraced the existing form, crafting a future-proof home that both respects its past and looks ahead. The design incorporates a photovoltaic system that not only powers the house entirely on electricity but also produces a surplus of 7,000 kWh annually. This commitment to environmental performance is underpinned by passive design strategies and passive house principles, enabling the dwelling to shift between a sealed high-efficiency mode and natural ventilation depending on seasonal needs.

Materials were a critical part of the sustainability equation. Wherever possible, existing elements—such as aluminium cladding, hardwood window frames, and an in-ground 30,000-litre rainwater tank—were preserved. New additions were carefully chosen for low embodied carbon, including recycled hardwood cladding, carbon-neutral concrete, and Australian-made tapware from Sussex.

The home’s landscape strategy also plays a crucial role. Instead of extending outwards, the architects sculpted a coastal deflection berm from the site’s monzonite rock to shield the house from surf surges. This berm anchors the building to the land, supported by stepped seating, native planting, and permeable hardscaping. A removed Norfolk Pine was replaced with a species endemic to the region, enhancing local biodiversity.

Inside, the flexible floorplan is tailored for entertaining, maximising sea views and daylight, while the lower-ground bedrooms function as a thermal bunker—cool in summer, warm in winter, and ideal for a changing climate. Located within a 2100 Coastal Hazard Zone, the upgraded home now boasts a projected negative carbon footprint over 55 years, continuing to offset emissions well into the future.

By preserving the spirit of the original and investing in resilient, regenerative design, Alexander Symes Architects has elevated the Cake House from local icon to model of ecological innovation.

Images by Barton Taylor via designboom