Can you renovate an old Melbourne house and turn into a Passive House?
Achieving the full Certified Passive House standard on a renovation is a major undertaking, but it is possible through the EnerPHit standard. This specialised retrofit focuses on re-engineering the building envelope—specifically airtightness, high-performance windows, and continuous insulation—to reduce energy demand by up to 90% in existing Melbourne homes.
Carland Construction Proof Point: At the Rifle Range Certified Passive House Retrofit (Williamstown), we transformed a leaky, traditional timber-framed home into a high-performance sanctuary. By meticulously addressing the existing structure, we proved that you don’t need to knock down and rebuild to achieve elite thermal comfort and radical energy savings.
Is it possible to do a Passive House renovation in Melbourne? The short answer is yes, but you have to stop thinking about decorating and start thinking about engineering. Most Melbourne renovations focus on a new kitchen and an open-plan extension while leaving the original draughty cottage as a thermal liability. This is a missed opportunity to fix the home for the next 100 years.
To do this properly, Carland Constructions uses the EnerPHit standard. This is a modified version of the Passive House standard designed specifically for existing buildings. It acknowledges that we can’t always fix bad bones, like an uninsulated slab-on-ground, but it still demands a level of performance that makes standard 7-star builds look like glorified tents.
What are the biggest challenges with an EnerPHit retrofit? The bear we have to poke here is the existing structure. Typical Melbourne cottages—whether they are Victorian weatherboards or double-brick bungalows—were designed to leak air. As a Certified Passive House builder Melbourne specialists, we focus on three main hurdles:
Suspended Timber Floors: Retrospectively insulating and sealing a sub-floor is a difficult but essential task to stop the winter chill from rising through your floorboards.
Thermal Bridging: Old homes have thermal highways where heat escapes through original timber studs and uninsulated junctions.
Airtightness: Achieving the precision required for EnerPHit takes advanced membranes like Pro Clima and high-performance tapes to seal every structural penetration.
Can I just do bits of a Passive House? You can, but you have to be careful. If you install high-performance, airtight windows into a leaky, uninsulated house, you might actually create a mould problem because the windows are no longer the weak point where condensation happens.
At Carland Constructions, we advocate for a holistic system. If a full retrofit isn't in the budget today, we help clients create a Phased Retrofit Plan. This ensures every step you take now—like upgrading your insulation—doesn't lock you out of achieving high-performance results in the future.
Technical Performance Metrics: Rifle Range Certified Passive House Retrofit (Williamstown)
Airtightness Result: 0.49 ACH @50Pa. This is a scientific triumph, surpassing the 1.0 EnerPHit limit and even the 0.6 New-Build limit, reducing leakage by over 95% compared to the average Australian home.
Heating Demand: 32 kWh/m².yr. Calculated via PHPP, this represents a massive reduction from the 200+ kWh/m².yr typical of unrenovated Melbourne stock. While higher than the 15 kWh new-build target, this is a radical result for a building with existing structural constraints.
Window Upgrade: Triple-glazed units with an installed U-value of 1.00 W/(m²K), which cuts radiant heat loss through the glass by roughly 80% compared to original single glazing.
Are you ready to stop polishing a turd and actually fix your old Melbourne home? Contact Carland Constructions to speak with the Passive House specialists Melbourne homeowners trust for complex retrofits.