How to Reduce Your Power Bill: The Real Impact of Insulation
30 March 2026
If your home feels cold in winter and expensive to heat, you’re not alone. In New Zealand, heating can make up around 30% of household energy use, and possibly even more in the deep south. Without insulation much of that heat is simply escaping through your roof, floor, and walls. If you really want to reduce your power bills, you need to keep that heat in, and the cold out. So the real question isn’t just “how much does insulation cost?”. It’s: how much are you losing without it?
How much can insulation actually save?
The short answer: more than most people expect. Insulation is, according to EECA (Energy Efficiency and Conservation Authority), one of most effective ways to keep your home comfortable, healthy and warm. And it can save you up to $330 each year on your power bills. The exact savings depend on the size of your home, how you heat your home and what level of insulation is installed. However it works in your home, with rising energy prices, the small savings add up quickly.
Insulation vs Heating: What saves more?
A common mistake we see is homeowners installing or upgrading their heating before fixing insulation. But here’s the reality – your heating generates warmth – insulation keeps it inside.
In fact, in an older, uninsulated home up to 60% of the heat you produce can be lost. Without insulation, even the best heat pump is working overtime – replacing the lost heat, and costing you more every month. That’s why insulation is often called “the foundation of an energy-efficient home”.
It’s not just about saving money
Yes, insulation reduces power bills — but the benefits go much further. Good insulation offers you:
- A warmer, more comfortable home year-round
- Less condensation and mould
- Better health (especially for kids and older adults)
- A reduced strain on your heating systems
In fact, improving insulation is a key part of New Zealand’s Healthy Homes Standards for rentals. It means your home is warmer and healthier.
Where you’ll get the biggest gains by insulating your home
If you’re looking to maximise savings, start here:
- Ceiling Insulation: Since heat rises, insulating your ceiling can have the biggest impact for most homes.
- Underfloor Insulation: Especially important in older homes with timber floors. This also stops the damp rising into the home, which helps to create a healthier, dryer home that is easier to heat.
- Wall Insulation: Blown in wall insulation is an easy and quick way to reduce heat loss by around 20% – 25%.
- Draught Stopping: Sealing gaps around windows can reduce energy loss by up to 25%.
- Ventilation: Ventilation is often overlooked, but it helps manage moisture and improves overall efficiency. A damp home is harder, and more expensive, to heat.
Is insulation worth it in Southland?
Yes, absolutely. Insulation provides savings on your power bill, improved comfort, health benefits and increases the value of your home. In fact, it’s one of the highest return-on-investment upgrades you can make to your home. Insulation isn’t a cost, it’s a long-term saving.
At Awarua Synergy, we help Southland homeowners create warmer, healthier and more energy efficient homes — tailored to our unique climate.
Book a free home assessment and find out where your home is losing heat (and money).
