*ECHO.1, Melbourne’s first Passivhaus-certified townhouses Photo: Tom Ross*

Melbourne has welcomed a groundbreaking development with ECHO.1, Australia’s first build-to-sell, multi-residential project certified to the Passivhaus Standard. Delivered by C Street Projects in collaboration with award-winning Neil Architecture, ECHO.1 is much more than just another townhouse project—it’s a blueprint for sustainable living in Australia.

A Commitment to Passivhaus From the Start

From the very beginning, C Street Projects committed to achieving Passivhaus certification, embedding airtightness, thermal comfort, and efficiency strategies into the design phase rather than as an afterthought. This forward-looking approach set the stage for innovation and problem-solving rarely seen in commercial residential ventures.

Bringing Global Standards Home

Passivhaus is well established in Europe, the United States, and Canada—but it remains relatively new in Australia. The team faced the challenge of adapting global best practices to local conditions, trades, and products. Through prototyping, workshops, and collaboration, they created an Australian approach to Passivhaus that bridges international knowledge with homegrown solutions.

Overcoming Technical Challenges

Delivering airtight, high-performance townhouses meant tackling complex technical hurdles—from connection details to thermal bridging. One standout solution was a cost-effective “sandwiching” method to mitigate thermal bridging at the basement-slab interface. By innovating with local materials and methods, the team developed strategies that can now guide future projects.

Certified Quality Assurance

Passivhaus certification isn’t just a label—it’s a rigorous process of testing and validation, including blower door tests and detailed energy modelling. At ECHO.1, the results spoke volumes: all eight townhouses achieved airtightness ratings of 0.36 ACH50, outperforming the Passivhaus standard of ≤0.6 ACH50.

Kin Seng Choo and Michael Robertson, the duo behind C. Street Projects, have spent the last five years developing a method and design approach to scaling certified Passivhaus projects suited to the unique challenges of Australian conditions.

Comfortable, Sustainable, and Profitable

ECHO.1 proves that sustainability and profitability can go hand in hand. The project was delivered as a market-rate venture while offering residents unmatched benefits:

Year-round comfort with stable indoor temperatures around 23°C.
Triple-glazed windows, intelligent membranes, and straw panel insulation for acoustic peace and quiet.
Continuous filtered ventilation for exceptional indoor air quality.
Net zero performance with solar panels, battery storage, and EV charging.

On average, the homes consume just 5000kWh/year—70% less than a typical Victorian home—dramatically reducing both energy bills and emissions.

Education, Upskilling, and Market Impact

C Street’s hands-on approach has not only delivered homes but also:

Upskilled consultants and trades, building local capacity for future Passivhaus projects.
Supported new businesses such as membrane installers and high-performance product distributors.
Created an educational display home to engage industry, developers, and the community, spreading awareness of high-performance building practices.

Setting a Benchmark for the Future

ECHO.1 represents a turning point for Australian housing. By proving that Passivhaus projects can be financially viable, technically achievable, and commercially successful, it sets a benchmark for sustainable, high-performance development at scale.

As Kin Seng Choo and Michael Robertson, the visionaries behind C Street Projects, explain:

“Australians should have access to sustainable homes built to global best practice. Turnkey homes certified to the Passivhaus standard provide independent verification and surety of quality.”

For residents, the benefits are immediate—comfort, quiet, clean air, and low bills. For the industry, ECHO.1 demonstrates what’s possible when great architecture meets world-leading performance standards. And for the future, it shows a pathway toward a better, safer, and more sustainable built environment.

Photography: Tom Ross

ECHO.1: Australia’s Pioneering Build-to-Sell Passivhaus Townhouses