Before we moved to the Coromandel, we lived in a recently renovated, classic 1860s villa in Auckland. It was truly gorgeous, with high ceilings, polished floors, and plenty of charm.

We lived in it, and in winter, we certainly felt the cold. Out of curiosity, I ran the energy model. The heating demand came out at 88 kWh/m²/year, one of the key measures used in Passive House design. At around $0.37 per kWh (today’s power price), that villa would cost roughly $3,435 a year just to stay warm. That’s not lights or hot water — just heating. In July alone, about $690.

Now compare that to our house here in the Coromandel, a certified Passive House Premium. Its heating demand is just 12.3 kWh/m²/year. Using the same calculation, that comes to $235 a year, or $63 for July.

Fifteen times less demand, ten times less cost — and that’s before you factor in comfort. In a house this efficient, even cooking generates enough warmth that the heat pump is barely needed. We might flick it on for an hour a few times over the whole winter, and we certainly don’t ever have to sit in a cold home seeing our breath hang in the air anymore.

If you then go solar, you don’t receive a bill from a power company ever again — something we look forward to every month!

Numbers like these make one thing clear: building smarter pays off, not just in savings, but in how you live. It’s time to stop thinking of a home as a one-off purchase and start considering the ongoing cost of living in it.

If you’re planning a build, we can help you understand your home’s performance before you commit, ensuring your comfort doesn’t come with a massive power bill.