ECHO.1

To achieve the unprecedented goals targeted by ECHO.1, C Street had to drive an integrated design strategy with unwavering commitment. The decision to commit to Passivhaus certification was made on acquisition of the site, justified by its ideal north orientation, level topography and rising environmental awareness in Hawthorn.

The solutions developed for ECHO.1 would likely be repeated and improved on for future C Street projects, and the industry broadly, so a “product design” mindset was adopted. Unlike a traditional development where the emphasis is on yield and cost, ECHO.1 prioritised thinking about systems, scale and details from the beginning.

The architect was clearly briefed about maintaining a compact form factor, reducing thermal bridges which occur at every junction, considering how continuous insulation was achieved, and to be strategic about window placements. Concurrently, C Street accelerated the design development phase early on to resolve key strategies for airtightness, continuous insulation, thermal breaks, triple-glazed windows and heat recovery ventilation – the core principles of Passivhaus.

An additional Passivhaus consultant was brought onto the team early, to test and validate new wall assemblies that had never been used before. C Street sent Durrapanel samples away for lab testing, to obtain vapour permeability results used for condensation risk analysis. C Street gathered a team of experts, and used in-house construction expertise to create a project that was feasible, albeit requiring non-traditional methods.

C Street successfully tendered and worked with Creation Homes to deliver ECHO.1. Through construction, C Street meticulously controlled quality and documented the project to meet the certification requirements. Blower Door Testing near the end validated the approach and effort, with all eight homes achieving <0.6ach. With residents moved in and the project certified, the homes really perform excellently, and the design brief has been truly achieved.

The design of ECHO.1 has been considered holistically, ensuring practical, spatial functionality, curated interior architecture and selection of finishes, and building performance founded on the Passivhaus standard. The homes are designed for easy living, starting with generous and secure private double garages.

Private lifts offer ease of access, and durable tiled floors are used for high-traffic communal areas. Secondary bedrooms are conveniently zoned on the top floor, with a small study, making it ideal for growing families and multi-generational living.

The aesthetics are a thoughtful response to the Hawthorn heritage context, using robust brick and metalwork in clean lines and subtle faceting to create a simple, permanent façade that harmonises with the streetscape while concealing scale. CCTV coverage and secure entries provide security.

The rigorous Passivhaus certification process is a great quality assurance tool, and independent building inspection was also carried out by C Street as part of commissioning. As the first Passivhaus certified development in Australia, ECHO.1 has raised the bar with energy efficiency, while coupling turnkey solar and battery options to offer a complete, turnkey future-proofed housing solution.

User experience is deeply integrated into the design. The Passivhaus standard ensures exceptional thermal comfort (stable 23°C year-round with minimal HVAC), superior air quality through heat recovery ventilation, and quiet interiors, offering a sense of serenity and well-being. Reduced mould, damp, and draughts improve quality of life and health outcomes. Accessibility is enhanced with private lifts.

As the first of its kind, ECHO.1 introduces high-performance buildings to the multi-residential market and represents design excellence in its approach as a housing solution.

The efforts to rapidly increase housing supply should not come at the expense of housing quality and performance. However, amidst rising cost escalation, skill shortages and worsening affordability, there is a real possibility that homes will cost more and perform worse.

With buildings being long-lived assets, and projections of a more extreme climate, we cannot afford a backward step. ECHO.1 is demonstrating that the industry can implement high-performance methods while maintaining commercial returns. By aiming for - and achieving, the stringent Passivhaus standard, C Street has shown that we can build airtight homes with great insulation, ventilation and quality windows.

The way that Passivhaus homes are being delivered domestically were not scalable, and new methods and strategies had to be developed for ECHO.1. Firstly, C Street simplified the airtightness strategy to an external wrap, compared to the internal layer commonly used in Australia. A unique wall assembly was created, using traditional 90mm timber frames with Durrapanel as an external sheathing that was wrapped with a Proctor Wraptite membrane.

Durrapanel is a compressed straw panel made in Bendigo that had never been used in such a way, but had all the properties to do so – providing insulation, fire resistance and structural strength. Testing and collaboration with all the suppliers, consultants and key trades was carried out to ensure it worked.

Moving the airtightness layer to the outside reduced the number of trades that had to be educated about Passivhaus, and made sealing the penetrations much easier. C Street also engineered innovative performance solutions to permit the use of ventilation ductwork within a Class 2 building, addressing the thermal bridge at the suspended slab, and solving for make-up air balancing with a ducted rangehood – to name a few other technical challenges.

ECHO.1 provided an opportunity to develop and validate scalable technical solutions for commercial Passivhaus delivery in the Australian context, that will lead to more projects and better access to these types of homes for Australians. The thermal comfort at ECHO.1 has improved the well-being, productivity and quality of life for the families that call it home.

The solar and battery provision has massively reduced bills and our residents have a 100% electric vehicle fleet using the 7kW chargers on hand. Net Zero homes like ECHO.1 clearly benefit the environment and society. With very low energy demand coupled with solar and battery, we can densify inner cities without placing pressure on limited grid infrastructure. This is already coming under stress with the push towards EV’s and the phasing out of gas. There is also no pressure spike during peak demand hours in the early evening, supporting the phase-out of fossil fuel peaking and baseload plants.

Passivhaus homes have also been rigorously modelled and checked during construction, meaning a more robust structure that is not susceptible to mould and rot. Homes that have long life cycles are more sustainable. The use of carbon sequestering materials like Durrapanel, and low embodied energy bricks from LOHAS that were produced from biogas, further reduce the upfront carbon impact in addition to the low operational carbon emissions.

C Street is proud to have delivered Australia’s first Passivhaus-certified development in Hawthorn, Victoria, with an all-Victorian design team featuring unique local products. A furnished display has been set up with educational signage to host industry events and open days to share knowledge and inspire others to adopt more sustainable practices. C Street has hosted delegations from developers and architects, and it is likely that ECHO.1 will spur the growth of more high-performance projects soon.

ECHO.1 offers exceptional energy efficiency, achieving Passivhaus certification, which means reduced operational carbon. These measures result in homes designed to use around 5000kWh/yr, which is 70% less energy than typical Victorian homes. The all-electric homes generate and store about 6000kWh/yr, allowing for net zero operation, and incorporate highly efficient systems like the Reclaim heat pump hot water system (COP of 5), reverse cycle air-conditioning and energy-efficient V-Zug appliances.

The project also reduces embodied carbon with Durrapanel, a compressed straw panel that sequesters 31kg CO2/m2, and has a low embodied energy of 12MJ/m2. LOHAS bricks, used extensively, are produced in a biogas kiln and perforated to reduce firing time and transport weight. Materials like masonry, aluminium, steel, tiled floors and granite were chosen for durability and low maintenance, prolonging life cycles.

The condensation analysis undertaken and use of vapour-permeable materials ensures that the structure is protected from moisture, enhancing longevity. The site has a north-facing orientation, compact form-factor and strategic windows with deep reveals to maximise light while optimising heat gain. Ten deciduous canopy trees also help with the passive design.

Lush landscaping provides wildlife habitat, and generous deep soil planting provides connection to nature. ECHO.1 has a 16kL rainwater tank for reuse in toilets and irrigation, and water-efficient fixtures with 4- and 5-star WELS ratings are specified.

The project actively serves as an educational tool, aiming to raise awareness among the public and industry about the benefits of high-performance, sustainable building and encourage wider adoption of these principles. Overall, ECHO.1 represents excellence in sustainable design by integrating world-leading performance standards, resulting in homes that are highly energy-efficient, comfortable, healthy, and designed for longevity.