What makes Masterton different
Officially a polluted airshed
In July 2024, Local Democracy Reporting said Masterton would stay a polluted airshed for at least another five years, after a second PM10 breach of the national air quality standards that year. Only one breach a year is allowed.
Wood smoke is the main cause
A Greater Wellington Regional Council report in June 2026 said wood burning raises PM2.5 levels through winter. Masterton West, the official monitoring site, has averaged more than 50 high-pollution days a year since 2021. The World Health Organization guideline is no more than three.
Burners outnumber everything but heat pumps
In the 2023 Census, 66.01% of Masterton District homes used a heat pump and 63.5% a wood burner. Only 4.23% used a fixed gas heater, and 28.94% an electric heater.
Hard, frequent frosts
NIWA's frost table gives Masterton, Te Ore Ore 81.0 ground frosts and 40.8 air frosts a year, with 9.8 air frosts in July. MBIE's H1/AS1 puts Masterton District in climate zone 4, a zone colder than Wellington City. The district council is Masterton District Council, and the town's postcode is 5810.
Real summer heat too
East Taratahi, near Masterton, averages 40 days a year above 25 degrees and 33 below freezing. Its 96 cooling degree-days and 2,106 heating degree-days are the highest of both in NIWA's Wellington table, and Waingawa holds the region's record of 35.2 degrees.
Swapping a wood burner for a heat pump
Measure the room the burner heats
A burner often warms an open-plan lounge, kitchen and hall at once, so the installer needs that whole space to size the heat pump. Our size calculator gives you a rough figure first.
Check the cold-weather output
On the label EECA regulates, compare heating capacity at 2 degrees with the figure at 7. EECA says where nights get to 2 degrees or below, the 2 degree number should be at least as high.
Pick the outdoor unit's spot
Somewhere open, off the ground and with air around the coil. With 40.8 air frosts in an average year at Te Ore Ore, it'll defrost often, so plan where that water drains.
Decide what happens to the burner
Some people keep a compliant burner as a backup for power cuts; others take it out. Any burner you keep adds to the winter smoke, so the less it runs, the better for the town's air.
What we'd do
What we'd do in a Masterton house
We'd put a properly sized heat pump in the main living area first, choosing the model on its 2 degree output, and use it for summer cooling too. We'd only keep the burner if it's in good order, and we'd burn it less. If the bedrooms are the cold part of the house, we'd look at a multi-room system rather than a second burner.