Retrofit Rifle
Residential: Single Dwelling
Passivhaus Plus Certification
Williamstown, VIC, 2024
The home was purchased in 2022 by the client to suit their growing family, and at the top of their list they were trying to find a sustainable home in Melbourne. Unfortunately, these types of homes are not easy to find, so the decision was made to purchase something and then turn it into something that would be more comfortable.
Initially, there was no conversation about creating a Passivhaus, but as the conversation evolved, they realised they needed a Passivhaus builder to aid them with their journey. So Carland Construction joined the conversation and started to work out what is possible in this house, and if it was possible to turn a once-volume builder house into a Passivhaus.
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AIRTIGHTNESS n50 ACH@50pascals: .4
HEATING DEMAND (kWh/m².yr): 32
COOLING DEMAND (kWh/m².yr): 5
PRIMARY ENERGY DEMAND (PE) (kWh/m².yr): 65
PRIMARY ENERGY RENEWABLE DEMAND (PER): 65 -
LOCATION: Williamstown, VIC
NCC CLIMATE ZONE: 6 – Mild temperate
NATHERS CLIMATE ZONE: 6
YEAR OF COMPLETION: 2024
TREATED FLOOR AREA (PHPP sqm): 152
PROJECT TYPE: Retrofit
SECTOR: Single Dwelling
CONSTRUCTION TYPE: Timber Frame
CERTIFICATION LEVEL/ ENERGY STANDARD: Passivhaus Plus
THIRD PARTY CERTIFICATIONS: Nathers -
MHRV SYSTEM: Zendher Q350
DOMESTIC HOT WATER SYSTEM: Reclaim 315L
EXTERIOR WALL TYPE, U-VALUE: Timber, .27
FLOOR SLAB TYPE, U-VALUE: Cork, .98
ROOF INSULATION TYPE, MANUFACTURER: Glasswool
ROOF CONSTRUCTION: Timber
ROOF ENVELOPE U-VALUE: .247
WALL FRAME TYPE, U-VALUE: Timber, .273
GLAZING TYPE, MANUFACTURER, U W-VALUE: Triple, Binq, 1.25, .53
EXTERNAL DOOR TYPE, MANUFACTURER: Timber, Binq
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The Rifle Range Retrofit in Williamstown stands as a pioneering achievement in Australian architecture because it was the first certified EnerPHit conversion of a standard 1990s volume-built brick veneer home.
The project’s success is anchored in its radical improvement of the building envelope, transforming a structure with an initial air leakage rate of 35 ACH to an extraordinary 0.41 ACH, surpassing even the strict .6ACH standard for new builds. This was achieved through the meticulous installation of an internal pro clima INTELLO membrane, which had to be surgically integrated into the original "dodgy" timber frame.
A standout, albeit challenging, feature was the use of a spray-in cork insulating screed, chosen for its dual role as high-performance thermal insulation and a low-VOC architectural finish. To manage the inherent risks of retrofitting a porous brick veneer without an external weather barrier, the team utilised hydrophobic polyester batts to prevent moisture transfer.
Mechanically, the home is powered by a Zehnder Q350 MVHR system, cleverly concealed within custom-designed bulkheads that double as aesthetic zone dividers between the kitchen and living areas. These technical feats are wrapped in a sophisticated biophilic interior, featuring extensive custom timber linings by Crafted Hardwoods and a signature curved wall finished with LED-cured hard-wax oils.
By balancing complex engineering, such as detailing triple-glazed windows into out-of-square brick openings, with high-end sustainable finishes, the Rifle Range Retrofit serves as a definitive blueprint for upgrading Australia’s existing housing stock to world-class thermal and acoustic standards.
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The retrofit of Rifle Range Passivhaus was defined by three significant technical and logistical hurdles. First, the installation of a cork-based insulating screed proved problematic; the product’s performance has been inconsistent, and these issues were exacerbated by an unreliable contractor whose poor management disrupted the critical workflow.
Second, integrating high-performance windows into the existing brick veneer required complex detailing. Because the external cladding remained untouched, the team had to engineer waterproof, airtight seals within openings that were significantly out of level and square, necessitating bespoke structural adjustments.
Finally, achieving Passivhaus air-tightness on an aging, "dodgy" frame was a monumental task for the team. Restricted to an internal membrane strategy, they had to meticulously seal every irregular junction from the inside, leaving no margin for error in an existing structure that offered very little inherent protection against air leakage.
Project Members
PASSIVHAUS CERTIFIER: HIP v HYPE
PASSIVHAUS CONSULTANT/ DESIGNER: Passive Analytics
INTERIOR DESIGNER: HeHe Design
CONTRACTOR/ BUILDER/ PROJECT MANAGER: Carland Constructions
WINDOW SUPPLIER: Binq
HRV SUPPLIER: Passive Tech
AIRTIGHTNESS MEMBRANE SUPPLIER: Proclima + Performance Membranes
BLOWER DOOR TESTER: Passive Tech
PHOTOGRAPHER: Marnie Hawson