N
Nigel and Gina Easterbrook
20 February 2025
★★★★★
Thanks so much for your fantastic service. Highly highly recommend to all. Nigel and Gina Easterbrook.
Guide
What Size Fire Do I Need?
Too small and a fire struggles on the coldest nights. Too big and it runs slumbering, wasting wood and glass staying black. Here is how to get it about right before we measure up.
Start with the heating area
Every fire on our website lists a heating area in square metres. It’s the most useful number to compare: measure the floor area of the room or open-plan space the fire has to heat (length × width) and choose a fire whose range covers it, ideally with your space in the middle of the range rather than at the top.
The kW output tells you how much heat it can make flat out. Bigger homes and open-plan living need more; a single lounge needs less.
Things that push you up or down a size
- Insulation — an older, uninsulated home needs a bigger fire than a modern, well-insulated one of the same size.
- Ceiling height — raked or high ceilings mean more air to heat.
- Open plan — if kitchen, dining and lounge are one space, size for the whole space.
- Glass — big windows and sliding doors lose heat quickly.
- Coast vs inland — inland and higher sites get colder nights than the coast.
There’s no official New Zealand formula. One European maker’s rule of thumb is about 1 kW for every 15 m³ of room volume (floor area × ceiling height) in a normally insulated home, about half that in a very well insulated home, and a size up if it’s poorly insulated. Treat that as a starting point, not a rule.
A quick example
An open-plan living area of 8 × 7 m with a 2.4 m ceiling is 56 m² and about 134 m³. By the rule of thumb that’s around 9 kW for an average home — so you’d look at fires whose heating area comfortably covers 56 m² and more if the hallway and bedrooms should get some warmth too.
When we do your free site check we look at the room, insulation, ceiling and where the flue can go, then recommend two or three fires that fit. Browse the range by heating area on Shop Fireplaces.
Sources
Official guidance we checked when writing this page (November 2026). Rules and fees change, so check the source or ask us before you rely on a figure.
Good to Know
Common questions
Is a bigger fire better?
Not always. A fire that is too big for the space gets turned down low, which burns less cleanly and blackens the glass. Pick one that covers your space in the middle of its range.
What does the heating area mean?
It is the floor area, in square metres, the maker says the fire can heat. Measure the room or open-plan space and compare.
Questions?
Talk to a local expert
Free advice and an accurate installation quote from our team in Tauriko, Tauranga.