Does NZ Have a Minimum Ceiling Height?

The requirement

Here’s the short answer: the New Zealand Building Code does not set a minimum ceiling height for a house. There is no single number to hit.

The Building Code is performance-based. Instead of naming a height, clause G5 “Interior Environment” asks for an adequate, controlled interior temperature, and that habitable spaces have enough room for activity, furniture and any mobility aids (NZ Building Code G5, clause G5.3.3). It never states a floor-to-ceiling height in metres. The government’s own Verification Method G5/VM1 even says in plain words that no specific method has been set for checking G5. And the Acceptable Solution G5/AS1 has just one table of sizes — and that one is only for old people’s homes, with widths and floor areas, no ceiling height.

So kitchens, bathrooms and hallways don’t get a fixed ceiling height either. The same performance-based G5 covers them. In fact G5 leaves bathrooms, laundries, toilets, pantries, walk-in wardrobes and hallways out of the “habitable space” group altogether.

So where does 2.4 m come from?

Most chippies have heard “2.4 m”. That figure is real, but it lives in a different, older rule book — the Housing Improvement Regulations 1947, regulation 10. Councils run these regulations under their housing and health powers, and they bite mainly on housing that is let or lived in (rental and substandard-housing cases), not on the building consent for a house you build for yourself.

Under the Housing Improvement Regulations 1947	Minimum height, floor to ceiling
Habitable room in a new house	2.4 m
Habitable room in an existing house	2.1 m
Kitchen (habitable only if 80 sq ft / ~7.4 m² or more)	2.4 m new / 2.1 m existing
Bathroom, laundry, toilet, pantry, hallway	No minimum

A habitable room here means a room people live in. A small kitchen — under 80 square feet, about 7.4 m² — is not counted, and neither are the wet rooms or passages.

Headroom over a stair is set separately again, in the Building Code’s D1/AS1 access rules — see the sibling article below for those numbers. Don’t read a ceiling-height figure onto a stair.

Work it out on site

Say you’re squaring up a let house under the 1947 regulations, and a bedroom has a raked ceiling. It’s a habitable room in an existing house, so the height to reach is 2.1 m. Does it pass?

Drop the low bit. Measure in from the low wall to where the ceiling reaches 1.5 m. Everything under 1.5 m high is left out of the test. Say the room is 4.0 m × 3.0 m — that’s 12.0 m² — and the strip under 1.5 m eats up 0.5 m along the 3.0 m wall. That’s 0.5 × 3.0 = 1.5 m² gone. Floor area for the test is now 12.0 − 1.5 = 10.5 m².
Find half. Half of 10.5 m² is 5.25 m².
Check the height. Run the tape across the room and mark where the ceiling drops below 2.1 m. As long as at least 5.25 m² of that floor sits under a ceiling of 2.1 m or higher, the room passes.

The 10.5, 5.25 and 1.5 m² figures are just an example to show the steps — your room will give you different numbers. The heights (2.4 m, 2.1 m, 1.5 m) are the ones set in regulation 10.

Part of the New Zealand Building Code hub — one national rule book, with the plain-language guides and calculators.
Building the stairs, and need the headroom and step numbers? See NZ stair & barrier rules: riser, tread, handrails, barriers.

Sources

NZ Building Code, Clause G5 “Interior Environment” (First Schedule of the Building Regulations 1992; Acceptable Solution G5/AS1 and Verification Method G5/VM1, 1st edition, Amendment 2, effective 10 October 2011) — G5 is performance-based and sets no floor-to-ceiling height; G5/VM1 states no specific verification method has been adopted, and G5/AS1’s only size table covers old people’s homes. Read it at building.govt.nz.
Housing Improvement Regulations 1947, regulation 10 — the 2.4 m (new) / 2.1 m (existing) habitable-room heights, the kitchen 80 sq ft test, and the half-floor-area rule for sloping ceilings (disregarding parts under 1.5 m). Read it at legislation.govt.nz.
Adoption / edition caveat: New Zealand has a single national Building Code — no state, regional or council editions. The Building Code itself carries no fixed ceiling height; it is performance-based. The well-known 2.4 m figure comes from the separate Housing Improvement Regulations 1947, which councils administer under housing and health powers and which apply mainly to let or occupied dwellings — not through the building-consent process for a new owner-occupied build. Some of those 1947 provisions are now set aside for tenancies covered by the Healthy Homes Standards. Always confirm which rules your council applies before you rely on a height. (Confirmed against NZ Building Code G5 (1st ed., Amendment 2) and the Housing Improvement Regulations 1947 as at 25 September 2025; verified 2026-07-28.)

Frequently asked questions

Does the NZ Building Code set a minimum ceiling height?

No. The Building Code is performance-based. Clause G5 asks for an adequate, controlled interior temperature and enough space for activity and furniture, but it does not state a ceiling height in metres. So there is no fixed floor-to-ceiling minimum for an ordinary house under the Building Code.

Where does the 2.4 m ceiling height figure come from?

From a separate, older rule book — the Housing Improvement Regulations 1947, regulation 10. It sets a habitable room in a new house at 2.4 m from floor to ceiling, and 2.1 m in an existing house. Those regulations are run by councils and bite mainly on housing that is let or occupied, not on the building-consent process for a house you build for yourself.

Does a kitchen need a 2.4 m ceiling in New Zealand?

Under the Building Code, no — there is no fixed height. Under the Housing Improvement Regulations 1947 a kitchen only counts as a habitable room (so it would need 2.4 m new / 2.1 m existing) if its floor area is 80 square feet, about 7.4 m², or more. A smaller kitchen sits outside that rule. Bathrooms, laundries, toilets, pantries and hallways are not habitable rooms and have no minimum height.

What about the ceiling in a house I'm building for myself?

The Building Code sets no fixed ceiling height, and the Housing Improvement Regulations 1947 mainly apply to let or occupied dwellings through councils' housing powers — not through the building consent for a new owner-occupied build. Good practice still runs to a 2.4 m stud, but confirm what your council expects.

How do the 1947 regulations treat a sloping ceiling?

The required height only has to be reached over at least half the room's floor area. When you work that half out, you leave out any part of the room where the ceiling is under 1.5 m high.