The indoor unit gets all the attention. The box outside decides how well the system breathes, how easy it is to service, and whether your neighbour will be knocking on the door in July.
Where an outdoor unit can sit is decided locally, not by one national distance rule. Your council’s district plan sets noise limits that apply at or near the property boundary, and the unit’s installation manual sets the clear space it needs. Get both right and the install goes smoothly.
How close to the fence can a heat pump outdoor unit go?
Councils don’t set one fixed distance from the boundary. What district plans control is how loud the noise can be when it reaches the neighbour’s property, and that limit drops at night. So a unit can be legal a metre from the fence in one spot and a problem three metres away in another, depending on which way it faces and what’s around it.
Waimakariri District Council’s fact sheet is blunt about it: most noise issues happen when the outdoor unit is too close to the neighbouring boundary or not raised off the ground. It also points out that the council doesn’t check heat pumps at any building inspection, so the owner or landlord is responsible for meeting the district plan.
What noise limits apply in Waimakariri and New Plymouth?
These numbers apply only inside the district that sets them. Don’t carry them to another town.
| District | Daytime | Night and other times |
|---|---|---|
| Waimakariri | less than 50 dBA | less than 40 dBA at other times |
| New Plymouth | L10 50 dBA, 7am to 10pm | L10 40 dBA, with a maximum (Lmax) of 70 dBA, 10pm to 7am |
Waimakariri’s fact sheet also warns that you may not be allowed to use the unit if complaints are received.
Notice the pattern. Night limits are lower, and night is exactly when a heat pump works hardest on a frosty Canterbury or Taranaki morning. Other councils set their own numbers and their own measuring rules, and in some zones they differ again. Tauranga City Council, for example, describes permitted noise levels within defined zones in its City Plan. Check the district plan rules for your own address, or ring the council’s planning or environmental health team and ask for the limit that applies to your zone.
Why the distance from the fence isn’t the whole story
A decibel figure on a brochure is measured in set conditions. In your yard, the noise that reaches the boundary depends on the unit’s size, where it sits and how it’s fixed. Waimakariri names all three. A unit tucked into a corner between two walls, or bolted high on a wall facing the neighbour’s bedroom window, can sound louder at the fence than one further away on a solid base facing your own garden.
Check the sound figures in the sales brochure before you buy, and ask the installer to show you how the unit they’re quoting compares with the limit in your zone at night.
→ Related: Heat pump noise and what the rules say
Where should the outdoor unit go? Seven things to weigh up
Walk around the house with the installer and take each option through these:
- Which way does it blow? Face the fan towards your own section, not the neighbour’s windows or outdoor living area.
- How close to the boundary? More distance helps, especially from bedrooms next door.
- What’s it sitting on? A solid, level base raised off the ground beats a flimsy bracket. Waimakariri flags units not raised off the ground as a common noise problem.
- Is there open air around it? The unit pulls heat from the air, so it needs room to breathe. Anything that limits airflow around the outdoor unit cuts its performance. Keep outdoor furniture, pot plants and ornaments off and away from it.
- Where will the water go? In heating mode the outdoor unit can drip water. Make sure that water won’t land on a path, a deck or over the fence. Our guide on heat pump problems covers dripping in more detail.
- Can a technician reach it? It needs servicing. A unit wedged behind a water tank, or two storeys up without safe access, costs more every time someone works on it.
- How far is it from the indoor unit? Shorter pipe runs are tidier, and each model’s manual sets limits on pipe length and height.
→ Related: How to choose a heat pump installer
How much space does an outdoor unit need around it?
Every outdoor unit has minimum clear distances at the back, sides and front, and they’re set out in the maker’s installation manual. They differ between brands and models, so there isn’t one number that fits every unit. Ask your installer to confirm the spot meets the manual’s clearances, and keep it that way: don’t let a hedge grow over it or stack firewood against it.
If you’re thinking about a cover or screen around the unit, it has to keep the clearances and airflow the maker requires. Our guide on heat pump covers explains the options.
What other council rules apply to a heat pump outdoor unit?
Noise is the rule that most often matters for an outdoor unit, but it isn’t the only district plan rule. The district plan sets out which activities need a resource consent, and building work has to meet it. If your home has a heritage listing, sits in a special character area, or the unit would go somewhere unusual such as a front wall facing the street, ask the planning team whether any other rule applies. Our guide on building consent explains how resource consent and building consent differ.
→ Related: Who can install a heat pump in New Zealand
What to ask before you sign the quote
- Ask the installer where the outdoor unit will go and why.
- Ask for the unit’s sound figures and check them against your council’s night limit.
- If the unit will be near a boundary, talk to your neighbour before the install, not after.
- Check the spot meets the clearances in the installation manual.
Find an installer who knows your council’s rules
Whether you need one room heated or several, compare installers for high-wall heat pumps and multi-room systems, or pick your town to see who works near you.