If you manage rentals in New Zealand, the healthy homes heating standard calculation is the compliance job most likely to come back and bite you months later. Every private rental has had to meet the healthy homes standards since 1 July 2025, and heating is the standard where a perfectly good-looking heat pump on the lounge wall can still leave a property non-compliant. The figure that matters is not what the installer recommended or what suited the owner's budget. It is the required heating capacity produced by the Government's heating assessment tool, calculated from inputs you have to measure and record yourself.
What the heating standard actually asks of you
The standard requires one or more fixed heating devices in the main living room that can heat that room to at least 18 degrees Celsius, that together meet a minimum heating capacity, and that are an acceptable type. All three have to be true at once. A large heat pump mounted in the hallway fails the first test because it does not directly heat the living room. A 2 kW panel heater in a room that needs 4 kW fails the second. An unflued LPG cabinet heater fails the third no matter how warm it makes the lounge feel. With the compliance deadline behind us, there is no runway left: if you pick up a new management today, the heating assessment is a day-one task, not something to tidy up at the next renewal.
What counts as the main living room
The main living room is the largest room tenants use for general everyday living, usually the lounge. Open-plan layouts are where managers most often slip. If the lounge, dining area and kitchen flow into each other with no door or full wall between them, that entire connected space is what you measure. Doors that actually close count as a separation. An open archway or a breakfast bar does not.
Which heaters qualify
- Heat pumps, wood burners, pellet burners and flued gas heaters, as long as they are fixed and meet the required capacity.
- Fixed electric heaters, but only where the required capacity is 2.4 kW or less. Above that they can be used only to top up a qualifying main heater.
- Anything installed after 1 July 2019 must have a heating capacity of at least 1.5 kW.
- Open fires, portable plug-in heaters and unflued combustion heaters never qualify, whatever their output.
The inputs a healthy homes heating standard calculation needs
The heating assessment tool on the Tenancy Services website does the arithmetic. Your job is to feed it accurate measurements and to be able to show later where each one came from. Gather these on site:
- The address. The tool derives the climate zone from it. The coldest zones, including Central Otago and Queenstown Lakes, attract an additional allowance, so an identical room needs more heat in Wanaka than in Whangarei.
- Internal dimensions. Length, width and stud height, measured inside the linings. For open plan, measure the whole connected area.
- Glazing. Total glass area including the glass in ranchsliders and external doors, single or double glazed, and the frame material.
- Skylights. Measured separately, with their glazing type.
- Ceiling insulation. Present, partial or absent. Get into the roof space and take a photo.
- Wall insulation. If you cannot verify it, do not guess. The insulation statement in the tenancy agreement or a compliance assessment beats a hunch about the build year.
- Floor construction. Suspended timber with or without underfloor insulation, or a concrete slab.
- Adjoining unheated spaces. An attached garage or unheated conservatory sharing a wall changes the heat loss.
- Existing heaters. Make, model, rated heating capacity in kW, and install date.
On that last point, use the rated heating capacity from the manufacturer's data sheet, not the maximum or boost figure printed on the carton. Download the data sheet and file it with the tool's PDF output. If a claim ever reaches the Tenancy Tribunal, that saved output is what turns a hunch into a documented assessment.
Three worked examples
The figures below are illustrative and are here to show how the inputs move the answer. Always run the tool against the actual property.
1970s weatherboard, South Auckland, closed lounge
- Lounge 4.6 m by 3.8 m, 2.4 m stud, door to the hallway that closes
- Single-glazed aluminium joinery, roughly 4.2 sq m of glass including the ranchslider
- Ceiling insulation retrofitted to current levels, no wall insulation, suspended timber floor with underfloor insulation
- Mildest climate zone
Required capacity lands a little above 3 kW. That single result rules out the cheap fix. Because the requirement exceeds 2.4 kW, a fixed electric panel heater cannot be the main heater, so the owner is buying a heat pump even though the room is small and the climate is mild. The uninsulated walls and single glazing are doing the damage, not the floor area.
1990s home, Christchurch, open-plan living
- Connected lounge, dining and kitchen, 8.2 m by 4.5 m, 2.5 m stud, no doors between them
- Double glazed, about 9 sq m of glass
- Ceiling and wall insulation present, concrete slab floor
- Colder climate zone than Auckland
Required capacity comes out near 4.8 kW. The property already has a 4.0 kW heat pump installed in 2017 and the owner assumed that was close enough. The regulations do allow some latitude for qualifying heaters installed before 1 July 2019 that fall only marginally short, but the tool tells you whether that allowance applies to your specific numbers, and at roughly 83 per cent of the requirement this one does not clear it. Two ways out: replace the unit with a larger one, or add a second fixed heater to cover the shortfall. Because a qualifying main heater is already in place, a fixed electric panel heater of at least 1.5 kW is acceptable as the top-up, which is usually the cheaper path.
2016 townhouse, Queenstown
- Living area 6.0 m by 4.2 m, 2.7 m stud
- Double-glazed aluminium joinery with about 11 sq m of glass facing the view
- Insulated to the building code of the day, concrete slab
Required capacity sits near 5.6 kW despite the house being modern and well insulated. Two things drive it: the coldest climate zone allowance, and the sheer area of glass. Managers routinely under-order heat pumps for newer Queenstown Lakes and Central Otago properties on the assumption that good insulation solves the problem on its own.
Where these calculations go wrong
- Measuring only the lounge when the kitchen and dining sit in the same open space, which badly understates the volume.
- Using a heat pump's maximum output instead of its rated heating capacity.
- Forgetting the glass in ranchsliders, French doors and skylights.
- Assuming a 2000s build has wall insulation without checking.
- Specifying a 2.4 kW electric heater as the sole heater in a room needing more than 2.4 kW.
- Installing a compliant heater in the wrong place, so it does not directly heat the living room.
- Running the tool, acting on the number, then never saving the output.
Redo the calculation after any work that changes the inputs: a new ranchslider, a wall removed to open up the kitchen, or a retrofit insulation job that may improve the result.
Turning the number into a compliant install
Once you have the required capacity, the brief to the installer is short and hard to argue with: a qualifying heater of at least X kW, fixed, positioned to directly heat the main living room, with the data sheet and install date supplied on completion. Quotes only become comparable when every installer prices the same specification instead of sizing the job themselves. If you also want the commercial view of how trades scope and price this kind of repeat work, Construction Arbitrage is a useful read.
Where portfolios stall is procurement. Chasing three installers across several properties can eat a week per address. Platforms like PlanaJob let property managers post the job once and compare quotes from vetted contractors side by side, which is exactly the workflow our New Zealand property manager tools are built around. Get compliant heat pump installs quoted by PlanaJob-vetted installers in days rather than weeks: create an account and post the job with the required kW attached. More compliance walkthroughs sit on the PlanaJob blog.
FAQ
Does the heating standard apply to bedrooms?
No. The heating standard covers the main living room only. Bedrooms do not need fixed heating under this standard, although the insulation, ventilation, moisture ingress and draught stopping standards still apply throughout the property.
Can a wood burner satisfy the healthy homes heating standard calculation?
Yes, provided it is fixed, heats the main living room directly and meets the required capacity. Check your regional council rules first, because several regions restrict solid fuel burners in urban airsheds and attach conditions to new installs. Where that applies, a heat pump is the usual alternative.
The tool says my heat pump is a few hundred watts short. Must I replace it?
Not necessarily. If the heater qualifies and was installed before 1 July 2019, the regulations make some allowance for units falling marginally short, and the tool output will state whether yours clears it. If it does not, adding a second fixed heater to cover the gap is usually acceptable and cheaper than a full replacement. Keep the tool output and the second heater's specification on file.