7-Star Energy Ratings in Canberra: What It Means and Why It Matters
Canberra has some of the sharpest climate swings in the country, from sub-zero winter mornings to summer heatwaves. For a long time, staying comfortable at home came with big heating and cooling bills. That’s changed. Since 15 January 2024, new homes approved in the ACT have had to reach a minimum 7-star rating under the Nationwide House Energy Rating Scheme (NatHERS), along with a new whole-of-home energy budget under the National Construction Code (NCC).
If you’re planning a new build or a knockdown rebuild, it’s worth understanding what this means. An energy-efficient home in Canberra isn’t an optional extra any more. It’s the starting point, and how well it’s done makes a real difference to how your home feels and what it costs to run.
What Does a 7-Star Energy Rating Actually Mean?
NatHERS rates how well a home’s design holds its temperature against the weather outside, on a scale from 0 to 10 stars. A very low rating means the house does almost nothing to keep the cold or heat out. A 10-star home is unlikely to need any heating or cooling at all. The ACT minimum moved from 6 to 7 stars, which means a new home now needs noticeably less energy to stay comfortable through the year.
Canberra sits in NatHERS Climate Zone 24, where winter does most of the damage. In practice, a 7-star home relies on its walls, roof, slab and windows working together passively. They hold warmth in on frosty nights, while good orientation, eaves and the right glazing keep the harsh summer sun out.
The whole-of-home part is newer and gets less attention. It sets an energy budget for the fixed appliances in your home, like hot water, heating and cooling, and lighting, and allows solar to offset that use. Put simply, it’s no longer enough for the shell to perform well. The things you run inside it count too.
What Does It Add to the Cost of Building?
Building to 7 stars is a great thing for the people who live in the home, but it isn’t free, and we’d rather you hear that from us early than get a surprise when the quote lands. Here’s what the performance side of a typical four bedroom, two living, two bathroom home looks like for us.
Windows and Doors
This is usually the biggest single item. A standard aluminium window package for a home that size sits around $30,000 to $40,000. Upgrading to uPVC takes that to around $50,000 to $60,000, and thermally broken aluminium can reach $60,000 to $70,000. uPVC often performs as well as or better than thermally broken aluminium for less money, so it’s worth talking through both with us. Glazing is also where design makes the biggest difference. A big north-facing window can work hard for you, but the same window facing west can blow out both the rating and the budget.
Insulation Under the Slab
Everyone in Canberra knows the feeling of a cold slab in winter, and there’s a reason ugg boots are so popular here. Laying 50 to 75mm of XPS insulation under the slab keeps the concrete you walk on much closer to room temperature. It adds around $15,000 to $20,000 on its own, and on some designs it’s needed just to reach the 7-star minimum.
Ceiling and Wall Insulation
Moving up to R7 in the ceiling and R2.7 high-density batts in the external walls can add up to around $5,000.
Vapour-Permeable wraps and airtight detailing
Getting the wraps, taping and sealing right can add $15,000 to $20,000. We believe it’s one of the best investments you can make in a new home. A properly sealed house holds onto the heat you’ve already paid for, your air is cleaner, and you lean on your heating and cooling far less.
All up, a home built to perform properly typically carries around $50,000 to $80,000 [inc GST] in extra cost compared with the bare minimum approach, depending on design and selections. Not all of that is required to reach 7 stars. Some of it is what we recommend because we know the difference it makes to living in the home.
The good news is that this money keeps paying you back every day you live in the house, through lower bills and a home that’s comfortable all year round. It’s also why we work through performance at design stage, where small changes to orientation or glazing can save thousands, rather than paying for expensive fixes once the plans are locked in.
What This Means for You Day to Day
Lower Running Costs
Heating and cooling make up around 40% of the energy used in a typical Australian home, and in Canberra winters that share climbs fast. A well-built 7-star home holds onto the warmth you’ve paid for, so the heating runs less often and for shorter stretches. You’ll notice it in every quarterly bill, for as long as you live there.
A Home that feels Even and Comfortable
You know the feeling of a cold hallway, a bedroom that never warms up, or an upstairs that turns into an oven in January. A properly insulated and sealed home doesn’t have those hot and cold pockets. It stays warmer in July and cooler in summer without you constantly adjusting the thermostat.
Healthier Air
Condensation forms when warm indoor air hits cold surfaces, and that’s where mould starts. Better insulation keeps those surfaces warmer. But a tighter home also needs a plan for moisture, with the right wall wraps and ventilation so it can breathe properly. Get that right and you get drier, cleaner air, which matters a lot if anyone in the family has allergies or asthma.
Less exposure to rising power prices
Energy prices only seem to go one way. A home that needs less energy to heat and cool is less affected every time tariffs go up, and if you add solar, it can go a long way towards running itself.
A Home that holds its value
Standards only head one way. A home built well beyond the minimum today won’t feel dated when the next round of changes arrives.
How We Approach It at Freedom Built
Here’s what most people don’t realise. A star rating is a computer model of your design. It assumes the insulation is installed without gaps, the windows are sealed properly and the wraps are lapped and taped as drawn. Whether your home actually performs like a 7-star home comes down to how carefully it’s built.
That’s why we look at performance from day one, not as a box to tick at approval. As a design and construct builder, we bring the design in-house, so the people drawing your home and the people building it are on the same team. We model energy performance early, while there’s still room to adjust orientation, glazing and layout cheaply, rather than adding expensive fixes at the end.
On site, that means high-performance window packages, upgraded insulation, vapour-permeable wraps with proper ventilation, and careful attention to airtightness. Inside, we use low-VOC materials so the air you breathe is as clean as the house is efficient. Our approach is simple: designed to be built, and built as designed. For us, 7 stars is the minimum, not the goal.
If you’re comparing new home builders in Canberra, ask each one how they make sure the rating on paper is what you actually get. It tells you a lot about how they build.
Planning a new home or knockdown rebuild? Let’s talk about building something that performs well beyond the minimum.
Upgrade to a 7-star energy-efficient home and enjoy comfort with lower bills.
