Home and water heating

If your home is cold, you’re not alone. The temperature in the average Kiwi home is below the World Health Organisation’s recommended minimum of 18°C (Source: Stats NZ).

Heating can burn through a lot of energy. Here we’ll look at how you can keep a warm home and heat water with less energy and save money in the process.

How it works

Heating your home

Heat pumps are one of the most efficient ways to heat and cool your home – in fact they produce more energy as heat than they use! According to the Building Research Association of NZ (BRANZ), they’re also cheaper to run than other forms of heating.

Put simply, they work by extracting heat energy from the air outside your home, and transferring it inside your home. Because they’re simply moving heat that’s already in the room rather than generating or ventilating it, they’re more energy efficient. Find out more about heat pumps at Gen Less.

While heat pumps are great for heating large spaces such as living areas, the upfront cost may be hard to justify for smaller spaces and bedrooms. Electric heaters such as panel heaters can be a good option for these areas as they’re cheaper to buy. But they’re also more expensive to run, so make sure they’re ‘smart’ with a thermostat and timer, or programmable, to avoid wasting electricity. Find out more about electric heaters at Gen Less.

Water heating

Hot water accounts for a whopping 30% – or even more – of household power bills (Source: Hot water energy saving tips at consumer.org.nz). You can reduce that by:

  • reducing the amount of hot water you use by installing low flow showerheads, fixing dripping hot taps and just taking shorter showers
  • keeping hot water hot for longer, by insulating hot water cylinders with cylinder wraps and pipe insulation which are sometimes called lagging and both available from hardware stores. 

How much it costs

Heat pumps

It depends on the size of the space you want to heat, the type of heat pump and energy rating label – the more stars, the more energy efficient. Here’s a rough guide to the cost of a single heat pump, including hardware, installation and GST:

  • For a small living area: $2,000 - $2,500
  • For a medium sized living area: $2,500 - $3,500
  • For a large living area: $3,000 - $5,000

(Source: Heat Pump Guys)

Smart Panel Heaters: 

  • Around $400 on average

Try the Efficient Appliance Calculator from Gen Less to find the one for you.

Water heating

  • Water efficient shower heads: from around $150 - $250, or you could choose to install a flow restrictor yourself for around $10
  • Hot water cylinder wraps: from around $70
  • Hot water pipe insulation: around $5 per metre

Find out more at Gen Less.

Good Energy Upgrades are just one step away


Heat pumps need regular maintenance to perform at their best. The main task is cleaning the filters, which you’ll need to do at least every quarter, as well as keeping the vanes and fins where the warm air comes out clean. The outside unit needs to be kept clear of vegetation or debris that might be blocking airflow and grilles, and regularly checked for corrosion. It’s also a good idea to get a professional to give it a once-over anually.

Benefits — for you and the planet

Using renewable energy

Using energy more efficiently means less need to top up New Zealand’s renewable energy supply with electricity generated by burning coal and gas.

Reducing air pollution

Replacing popular but less efficient wood burners – especially older ones – with clean, efficient heat pumps reduces air pollution from smoke particles and other contaminants.

Saving water

As well as reducing the cost of heating water, installing low flow showerheads and fixing dripping taps conserves water – an increasingly precious resource.

Is it right for you?

Everyone can benefit from making their home more energy efficient. But there are a lot of options, so where do you start?

It depends, of course, on your home and your budget, and you don’t have to do everything at once. For example, you should focus on improving your insulation before thinking about upgrading your heating, as otherwise you’ll lose the heat you’re paying for through ceilings, floors, walls, windows and gaps.

And while options like heat pumps are big investments that may not be doable in the short term, there are a lot of things you can do right now to make your home warmer and more energy efficient. Things like stopping draughts, wrapping hot water cylinders or installing window film are relatively simple and inexpensive ways to improve the efficiency and comfort of your home.

Other things to think about

Heat pumps

All heat pumps offer a modern, low-carbon solution – but some are more efficient than others. If you’re thinking about buying one compare Energy Rating labels before you buy.

Warmer Kiwi Homes Programme

Depending on your situation you may be eligible for a Warmer Kiwi Homes grant from the government. Grants can cover:

  • 80-90% of the total cost of ceiling and underfloor insulation
  • Up to 80% of the cost of an approved heater (e.g. heat pump)

 Find out if you’re eligible for a Warmer Kiwi Homes grant.

How to get home and water heating


HomeFit self-assessment is a straightforward way to check if a home is warm, dry, efficient and safe. You can use it to check a home you’re looking to buy or rent, or if you want to know how you can improve your current home. It starts with a simple online check.

If you would prefer to speak to someone you can contact an independent HomeFit assessor who can visit your home to provide a detailed assessment and list of priorities. 

HomeFit was developed by the New Zealand Green Building Council and is proudly supported by ANZ.

Important information

The material is information only and you should seek professional advice about your circumstances. While we’ve taken care to ensure the information is reliable, we don’t warrant its accuracy, completeness, or suitability for your intended use. To the extent the law allows, we don’t accept any responsibility or liability arising from your use or reliance on this information.