Heat pumps are the cheapest form of heating and unflued gas heaters are the most expensive. Natural gas is the cheapest form of central heating.
Electricity

A heat pump is the cheapest electric heating option to run – but to run efficiently it must be the right capacity for the house and it must be installed correctly.
Discounted night rates (if available) make nightstore and underfloor heating comparatively cheap, although you may need a new meter. As well, the heat may be released at inconvenient times.
Plug-in heaters are the most expensive form of electrical heating. For modern well-insulated homes we recommend convection or oil-column heaters because the warm air won't leak away. For poorly insulated older houses with high ceilings, radiant heaters are likely to be more effective – you can feel their heat more directly. However, they shouldn’t be used in bedrooms or around young children.
Our cost calculations for electricity come from our Powerswitch website. There was a big difference between the highest and lowest prices for each type of heating.
How clean?
Our electricity comes from a combination of renewable (wind, hydro and geothermal) and non-renewable (gas and coal) sources – so it's only a semi-clean fuel. But in your home, nothing is cleaner. Despite the inexorable rise in the price of electricity, electric heating provides a clean and easy way to heat your home.
More information
- Compare electricity prices on Consumer Powerswitch
- Choosing an electric heater
- Convection heaters
- Heat pumps
- Insulation
Firewood

A woodburner is a cheap way to heat your home – if you can get free or cheap firewood. We’ve used prices for pine firewood in our Fuel prices compared table as it was the cheapest and most widely available wood in our survey of firewood prices. Delivery is usually part of the price but this depends on distance.
We haven’t calculated the cost of burning wood in an open fire. Open fires are inefficient (heat is lost up the chimney) and cause massive pollution for the heat they do produce.
Tip: Buy early – during spring or early summer – and phone around for prices. We found some good deals in our firewood survey.
How clean?
Along with wind and hydro, wood is one of the few sustainable carbon-neutral home-heating options. But to get the most heat (and the least pollution), it must be burned hot and in a specially designed firebox. The firewood must also be dry and the pieces not too big (less than 11cm in diameter).
Some woodburners can be used to heat wetbacks but this reduces their efficiency and may also overheat the water.
More information
Wood pellets

Wood pellets are used in burners and also in boilers for central heating. The pellets are sold in 15kg or 20kg bags. Our price survey found big variations – prices were generally lower in the South Island.
Pellet burners cost more to run than woodburners but they have their advantages. They produce less atmospheric pollution and the pellets are largely carbon neutral because they’re made from waste wood (compressed sawdust and wood shavings).
A pellet burner is one of the cheaper forms of central heating. As well, wood pellets are the only type of central-heating fuel that’s a renewable resource.
More information
Natural gas

It’s cheaper to run your flued heater or central heating on natural gas rather than on LPG. Unfortunately, reticulated (piped) natural gas is available only in the North Island.
Prices for natural gas can fluctuate, as they do for LPG and diesel. They’re world commodities and subject to rapid price changes that are out of the householder’s control.
Our cost calculations for natural gas came from our Powerswitch website.
Tip: “Dual fuel” discounts for buying gas and electricity from the same provider are generally cheaper than paying for gas alone.
How clean?
Natural gas is clean-burning for pollutants, but it's a fossil fuel. Burning it adds the greenhouse gas carbon dioxide to the environment.
More information
LPG

Prices for the 45kg cylinders of LPG delivered to your door include the cost of delivery – which means people in rural areas pay more.
Running an unflued heater on 9kg bottles is the most expensive way to heat your home. It also presents a health and safety hazard: unflued heaters create condensation and produce CO2.
Warning: If a fault develops, an unflued heater can emit a poisonous gas called carbon monoxide. This can build up in a room and become a significant health risk for children, pregnant women and people with asthma or heart disease – and high levels of it can be fatal to anyone. For this reason an unflued heater should only be used in rooms with good ventilation and should never be used in bedrooms.
How clean?
Like natural gas, LPG is clean-burning but adds carbon dioxide to the environment.
More information
Diesel

Diesel boilers heat water used for central heating through water-filled radiators or underfloor heating. Stand-alone diesel heaters are available and are designed to look like a wood fire.
Diesel prices can change rapidly depending on the world price. In February 2013 the price of diesel was less than one percent higher than its February 2012 price, but during those 12 months there was an 11 percent difference between the highest and lowest prices.
How clean?
Diesel is an atmospheric pollutant and a non-renewable resource.
The sun
It's free, and the most environmentally-friendly home heating option available. You'll need large north-facing windows to allow the sun to shine in during the day, a large thermal mass such as a concrete floor to store the heat, and insulation so the heat isn't lost too quickly at night. And you'll probably still need other heat sources for the coldest days.
If you're designing a new home, incorporating some passive solar heating into the design may not cost very much at all. It may also be possible to include some solar features when you're renovating, but it's harder.
More information
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