This calculator estimates the heating capacity in kilowatts your main living room needs to meet New Zealand's Healthy Homes heating standard, which requires rental properties to have a fixed heater able to warm the living room to at least 18 degrees. Landlords often guess at heater size or assume an existing heat pump is enough, but the standard sets a required capacity worked out from the room itself, and a heater that is too small does not comply no matter how modern it is. The capacity needed grows with the size of the room, falls with better insulation, and rises in colder parts of the country, because all three change how much heat the room loses on a cold day. You enter the living room's length, width and height, choose how well insulated it is, and pick your region's climate, and the calculator returns an estimated heating capacity in kW along with the room volume it is based on. Use it to sense-check a heat pump or fixed heater before you buy, or to understand roughly where your room sits. For an actual tenancy you must confirm the compliant figure with the official Tenancy Services Healthy Homes heating tool, since that is the formula the law refers to. This is an estimate and general information only.
An estimate based on room volume, insulation and climate. Confirm the compliant figure with the official Tenancy Services Healthy Homes heating tool. General information only.
The calculator works out the room volume as length times width times height, then multiplies by a heat-loss factor for the insulation level and a multiplier for your region's climate. The result is an estimated heating capacity in kW. Better insulation lowers the factor; colder regions raise the multiplier.
A 5 by 4 metre living room with a 2.4 metre ceiling is about 48 cubic metres. At a moderate insulation factor and a mild climate, the estimate is roughly 3.1 kW, so you would look for a fixed heater or heat pump rated at or above that.
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