Building Smart
Winter power bills in Tasmania can be brutal — but the culprit isn't your heater or your energy retailer. It's the building. Here's what really drives heating costs, and how a better-built home cuts them by most, permanently.
Every winter, the same conversation: the power bill lands, and it’s a shock. The instinct is to blame the energy retailer, the heat pump, or the price of electricity. But those are rarely the real cause. In a Tasmanian home, what drives your heating bill more than anything else is the building itself — and that’s both the bad news and the good news.
Think of your home in winter like a bucket you’re trying to keep full of warm water. The heater is the tap filling it. But if the bucket is full of holes, you have to leave the tap running constantly just to keep the level up — and you pay for every litre.
That’s exactly what happens in a leaky, under-insulated home. Heat pours out through air gaps, poorly insulated walls and ceilings, and low-performance windows almost as fast as your heater makes it. Your bill isn’t high because your heater is inefficient. It’s high because you’re heating a building that can’t hold the heat, so the heater almost never gets to switch off.
Plug the holes, and the same heater does a fraction of the work.
If you want a lower heating bill, these are the levers that matter — in roughly this order of impact:
1. Airtightness. Uncontrolled draughts are one of the biggest and most overlooked heat losses in an Australian home. Sealing the building envelope stops warm air escaping and cold air pouring in. It’s invisible, and it’s the cheapest big win in building.
2. Continuous insulation. Insulation only works if it’s continuous — gaps and thermal bridges leak heat and undo much of the benefit. Done properly, a well-insulated envelope keeps the heat you’ve paid for inside the building.
3. Performance glazing. Windows are often the weakest point in the whole envelope. High-performance double or triple glazing dramatically cuts the heat lost through the glass — certified Passivhaus windows transmit around one-sixth the heat of a standard Australian window.
4. Controlled ventilation with heat recovery. A well-sealed home is ventilated deliberately, with a heat-recovery system that supplies fresh air while capturing most of the warmth from the air it extracts — so you’re not throwing your heating straight out the vent.
Notice what’s not on this list: a bigger, fancier heater. Once the building holds heat, heating becomes almost an afterthought.
A lot. A home built to the certified Passivhaus standard uses roughly 80–90% less heating energy than a typical build. Our certified Passivhaus at Blackmans Bay was independently verified at a heating demand of just 10 kWh/m²·yr — a figure most Tasmanian homes miss by a wide margin. That’s not a marginal saving on the power bill; it’s a different order of magnitude, every winter, for the life of the home.
And it compounds. The savings don’t run out — they repeat every single year you live there, which is why the extra investment in the building fabric pays back over the life of the home. You can put your own bills into our Passivhaus savings calculator to see the range for your situation, using your numbers rather than ours.
Solar helps — but it works best after you’ve reduced how much energy the home needs in the first place. Panels on a leaky, energy-hungry house are trying to fill that holey bucket from the top. Fix the building fabric first, and a smaller, more affordable solar array covers far more of what the home actually uses. That’s the logic behind every eco home we build: reduce the demand, then meet the low demand cleanly.
If your heating bills are the reason you’re thinking about building or renovating, focus your budget where it actually moves the number — the building envelope, not the mechanical gear. It’s the difference between a home that costs a fortune to keep warm and one that stays warm almost for free.
See how we approach an energy-efficient home, or read the 2026 cost guide to understand where the money goes in a Tasmanian build.
Talk to our team — or get a 48-hour feasibility on your plans.
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