Multi-split heat pumps in NZ: costs and when they make sense

A multi-split sits between a single high-wall heat pump and a ducted system. You get an indoor unit in each room you want to heat, but only one outdoor unit on the side of the house. For many NZ homes that want the lounge and two or three bedrooms warm, it's the most practical option. It isn't always cheaper than separate units, though, and it comes with limits worth knowing before you buy.

What is a multi-split heat pump?

A multi-split is a heat pump system where one outdoor unit powers several indoor units, typically two to five. Each indoor unit has its own controls, so you can set different temperatures or turn rooms off, but they share the outdoor unit's capacity.

The indoor units can be high-wall, floor console or ceiling types, and you can mix them. A floor console in a lounge with big windows and high-wall units in bedrooms is a common combination.

How much does a multi-split heat pump cost in NZ?

A multi-split system costs about $5,000–$12,000 installed in NZ in 2026, with a typical price around $8,500. Price rises with the number of indoor units, the capacity of the outdoor unit and the length of pipe running to each room.

Pipe length matters more with a multi-split, because every indoor unit needs its own pipe back to the outdoor unit. Rooms at opposite ends of the house or on another storey add metres, and extra pipe runs about $50–$80 a metre. See the multi-split cost guide for more detail.

Is a multi-split cheaper than separate heat pumps?

Often, but not always. Consumer NZ says a multi-split is generally cheaper than buying several separate systems, though longer piping can push installation costs up. Get both options priced, especially if two rooms are far apart.

What are the downsides of a multi-split?

The main limits are that every indoor unit must run in the same mode, the rooms share the outdoor unit's capacity, and one outdoor fault affects every room. Consumer NZ notes you can't cool one room while heating another on a multi-split.

• Shared mode. If a sunny north room wants cooling while a south bedroom wants heat, one of them misses out.
• Shared capacity. Running every indoor unit at full power on a frosty night can stretch the outdoor unit. Correct sizing avoids this.
• Single point of failure. A fault in the outdoor unit takes out heating in every connected room.
• Fixed number of connections. Each outdoor unit supports a set number of indoor units, so plan for rooms you may want to add later.

When does a multi-split make sense?

A multi-split makes sense when you want to heat three or more rooms, you'd rather not have several outdoor units on the house, and a ducted system is too expensive or impractical. It's a common choice for villas and bungalows with no roof space for ducts.

• Homes with limited outdoor space, such as townhouses, where there's only room for one outdoor unit.
• Older homes where ducted heating would need major work to fit.
• Households heating a living area plus bedrooms on a timer at night.
• Owners who want a unit in each room but less visual clutter outside.

Compare the whole-home options on our ducted heat pumps page and in the multi-split cost guide.

How should a multi-split be sized?

Each indoor unit is sized for its own room, and the outdoor unit is sized to supply them together. The installer should calculate the heat each room needs, then choose an outdoor unit that can handle the combined load in your climate, not simply add up nameplate numbers.

Use our heat pump size calculator to estimate each room, and ask each installer how they sized the outdoor unit. Colder regions like Christchurch, Queenstown and Central Otago need extra headroom because output falls as outdoor temperatures drop.