The 90% energy saving claim is everywhere in Australian Passive House marketing. It is also, in the way it is usually stated, misleading. Not because Passive Houses do not perform. They do. But because the number comes from a comparison that most people quoting it do not understand, and using it without context does more damage to the credibility of certified Passive House construction than any critic ever could. Here is the honest version.

There are thousands of words written about what a Passive House is supposed to do. There are very few verified numbers showing what one actually does, in Melbourne's climate, in a real home, after construction is complete and people are living in it. These are those numbers.There are thousands of words written about what a Passive House is supposed to do. There are very few verified numbers showing what one actually does, in Melbourne's climate, in a real home, after construction is complete and people are living in it. These are those numbers.

A 7.1-star NatHERS energy rating sounds impressive. The Forrest Passive House in Spotswood has one. It also has a certified blower door result of 0.41 ACH50 and a heating demand of 13.1 kWh per square metre per year. Those are not the same thing, and understanding the difference could change every decision you make about your next home.

Anyone can claim a home is high performance. Very few builders have ever tested one. Here is every number from the Forrest Passive House in Spotswood, pulled directly from the certified PHPP post-construction file and the blower door test report.

Most builders will tell you their insulation levels exceed the minimum. They have no idea what their walls actually achieve. Here is every assembly in the Forrest Passive House in Spotswood, every U-value, every material layer, every heat loss figure, and exactly why each decision was made from a building physics and durability standpoint.

Most builders take the job and figure it out later. We priced a renovation, told the clients it was not good enough, and walked away from the fee. What happened next changed everything about how Carland Constructions builds.

Everyone wants the number. Fair enough. But if you are hoping it is the same price as a standard build with a few extra insulation batts, it is not. A certified Passive House is high-end architecture built to a verified performance standard. The honest answer is more nuanced than a single figure, and understanding why will change how you think about your budget entirely.

Every certified Passive House Carland Constructions has built performs at a level that would make most Melbourne homes look embarrassing. But one of our projects sits noticeably higher on the heating demand chart than the others. Some people see that number and assume something went wrong. Nothing went wrong. That higher number is the most honest thing on the page.

The industry is currently obsessed with theoretical stars. A 7-star energy rating assumes your insulation is perfect and your building envelope is tight. In reality, without a Blower Door Test, those stars are just a guess.

Most builders walk away from a site without ever knowing if the air control layer actually works. At Carland Constructions, we do not guess. We verify the building physics of every project so our clients know they are getting the performance they paid for.

The most common question we get is: How much more does a Passive House cost? The answer depends entirely on what you are comparing it to. If you are looking at a bare-bones volume build, there is a premium. But if you are comparing it to high-end custom architecture, a Certified Passive House usually sits at the exact same price point.

Most builders think they can hit 7-star energy codes by just stuffing more glass wool into the walls. In reality, thick insulation in a leaky building is a thermodynamic failure. It is effectively a conductive resistor being bypassed by convective heat loss.

We have analysed the data from three of our key Melbourne projects: Forrest, Champion, and Pigeon. While they share a similar scientific DNA, their unique site conditions and component selections show exactly how building physics works in the real world.

If you have been watching the news lately, mould fever is hitting Australia hard. Homeowners are terrified of sick building syndrome, and for good reason. For decades, we accepted the leaky tent as the Australian standard. But as the building code changes, we are heading toward a much more dangerous reality.

To the dictionary, sustainability is the ability to be maintained at a certain level. In construction, that definition has been twisted into a marketing shield. Most builders use it to hide behind a few solar panels while building a glorified tent.

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.

In the Melbourne building industry, we are facing a massive performance gap. Builders are churning out 7-star homes that actually perform like 2-star tents because they leak air, breed mould, and ignore the laws of building physics.

Pigeon Passivhaus (Yarraville) is the fix. It is a Certified Passive House Plus—a title held by only a handful of homes in Australia. It does not just save energy; it produces it. It does not just house people; it protects them.

There is a massive disconnect between what is on paper and what is actually built. Local audits suggest an energy performance gap where as-built homes can use up to 2.5 times more energy than the design predicted.

Building a sustainable home can feel like a minefield with so many buzzwords and conflicting ideas. It's hard to know what truly makes a home healthy, comfortable, and efficient. At Carland Constructions, we believe in a simple, science-backed approach. So, if you're looking to build a genuinely sustainable home in Melbourne, here are our top 10 tips.

Building a high-performance home is an investment in your future, but the "misinformation trap" often makes it difficult to understand where your money is actually going. To clear the air, let's look at the real-world differences between a Standard Custom Home and a Passive House, based on a typical 180sqm build.

Who needs hydronic heating in a slab when you can just insulate it correctly? It might sound like we're being cheeky, but when it comes to creating a truly comfortable and energy-efficient home, the ground is the first thing we should think about.