Converting a century-old, uninsulated cottage into a modern, climate-resilient home may sound like a daunting challenge. But for KC and Kirsty Kasturi, it was an opportunity to create a sustainable dwelling designed to withstand hotter years ahead.

The couple, both engineers in their 50s, moved from Singapore to Sydney in 2025 to be closer to their two daughters. Rather than building new, they set their sights on reimagining an existing property. Their goal was simple but ambitious: to minimise environmental impact while future-proofing the house.

“We’ve always been focused on living as sustainably as possible,” KC said. “We wanted to make sure the house was designed for the future.”

From Collapse Risk to Climate Haven

In 2022, the Kasturis purchased a double-brick Victorian cottage in Forest Lodge. While it looked sound from the inside, contractors later revealed that the structure was “pretty close to collapse.” The house lacked insulation and had single-pane glass throughout — the opposite of climate-smart design.

Working with architect Alexander Symes, the couple retained the historic 1900s brick exterior but replaced a poor-quality rear addition. The recycled bricks were reused in the new build, which included a two-storey extension made from carbon-neutral concrete and an insulated timber frame.

The house was upgraded with a moisture-regulating smart membrane, heat-recovery ventilation for indoor air quality, and vacuum-insulated windows that provide the equivalent of triple glazing. The design followed EnerPHit principles — an adaptation of the rigorous Passive House standard for retrofits — ensuring dramatically reduced heating and cooling needs.

Building for the Future

Symes, who specialises in sustainable architecture, said most Australian homes are not built to handle consecutive days of extreme heat.

“Our climate is changing, and we need to make our housing stock more adaptable. This is particularly important as heatwaves become more frequent and prolonged,” he said.

About 80 per cent of his practice’s projects now focus on retrofits rather than new builds, reflecting growing demand for homes that balance comfort, efficiency, and resilience.

For the Kasturis, the project was as much about principle as practicality. By reusing materials and reducing embodied energy, they aimed to lower the environmental footprint of construction.

“Recycled materials are often more expensive than new ones, but reusing what’s already there reduces overall impact,” Kirsty explained.

The build took around 18 months, following a year of design and council approvals. Red Cedar Constructions, a specialist Passive House builder, carried out the work.

A Home That Works With Nature

The completed home now features three bedrooms, two bathrooms, and a flexible secondary dwelling with lift access for future mobility needs. Solar panels power the house, rainwater is harvested for the garden, and no gas is connected.

Landscaping includes a greenhouse and a mix of edible and native plants designed to shade and cool the home as they grow. Black cockatoos and ringtail possums are regular visitors.

Inside, Japanese design influences are evident, with reclaimed timber and copper detailing adding warmth and character.

“You see the little nail holes in the recycled wood — it’s had a life before. Now it’s part of a new chapter,” KC said.

A Broader Shift

The Kasturis’ renovation comes as governments step up calls for new housing to be more sustainable. A federal report released this week warned of the risks posed by rising temperatures and set a new 2035 emissions target alongside funding commitments to accelerate decarbonisation.

Experts say projects like this highlight the importance of quality, medium-density development near transport links, and innovations such as modular housing to boost affordability while addressing climate pressures.

For the Kasturis, the result is not just a comfortable home, but also a blueprint for living sustainably in a warming world.

“It probably would have been easier and cheaper to build new,” KC reflected. “But making the old work again — and making it resilient — was worth it.”