What’s the Most Efficient Way to Heat a House in New Zealand?
Heating your home in New Zealand isn’t just about comfort—it’s about making smart decisions that keep your power bills down while keeping your home healthy and warm. But what’s truly the most energy-efficient and cost-effective way to do that? Let’s break it down.
Understanding Home Heating in NZ: Efficiency vs Cost
Why energy efficiency matters more than ever
New Zealand homes are notorious for being under-insulated and leaky. With rising electricity costs, choosing the right heating system and improving the building fabric are critical for long-term savings.
The true cost of poor insulation and outdated systems
A poorly insulated home with gaps and air leaks might cost you double to heat compared to a well-sealed, energy-efficient one. You're not just paying for heating; you're paying for heat loss.
Is it better to invest in windows, insulation, or heating?
Think of your home as a thermal system. Spending on heating without upgrading insulation is like heating a tent with a hairdryer. We recommend starting with a blower door test and energy modelling to see where your energy is really going.
Comparing Home Heating Options in NZ
What is the most energy-efficient form of heating?
Heat pumps are widely regarded as the most energy-efficient option in NZ, delivering 3–5 times more heat than the electricity they consume. Underfloor heating with hydronic systems can also be efficient, especially in well-insulated homes.
What type of heater is most energy-efficient?
High-performance split-system heat pumps (COP 4+) are top-tier. Wood burners and pellet fires follow, depending on fuel access. Electric fan heaters and oil heaters rank lowest.
Which heater is the cheapest to run?
Split-system heat pumps are generally cheapest per kWh delivered. A typical modern heat pump costs 10–12 cents per kWh of heat, compared to 30+ cents for electric panel or oil heaters.
Is a ducted heat pump or split system cheaper?
Split systems are cheaper to install and more efficient per zone. Ducted systems are ideal for larger homes but require better design and zoning to avoid wasting energy.
Heat pump vs split system: which is better?
These are often the same. “Split system” just refers to a type of heat pump with an indoor and outdoor unit. Multi-split systems can heat multiple rooms with one outdoor unit.
Are Oil Heaters Worth It in New Zealand?
Are oil column heaters expensive to run?
Yes. A 2000W oil heater running 8 hours/day at $0.30/kWh costs ~$144/month. They’re fine for occasional use but inefficient long-term.
Do oil-filled heaters use a lot of electricity?
They use constant power to maintain temperature, with no heat recovery. That adds up fast.
What is the disadvantage of oil heaters?
Slow to heat
No thermostatic control in cheaper models
Expensive to run
Localised heat only
Which oil-filled heater is best?
Look for models with digital thermostats, timers, and eco settings. Brands like DeLonghi are reliable.
Can you leave an oil-filled radiator on all the time?
You can, but it’s not recommended for cost or fire safety reasons.
How to use an oil heater efficiently
You probably can’t, but if you have no other choice:
Use in small, enclosed spaces
Shut doors to retain heat
Use a thermostat
How much does a 2000W heater cost to run in NZ?
Approx. $0.60/hour. 6 hours/day = $3.60/day = $108/month.
What's the Cheapest Way to Heat a House in NZ?
What is the cheapest way to heat a house?
Airtightness and insulation upgrades come first. Then, invest in a heat pump. For DIY savings:
Block draughts
Maximise solar gain
Improve floor, ceiling, and wall insulation
Note: We do not recommend thermal curtains due to the increased condensation risk in many New Zealand homes.
What is the cheapest way to heat a room?
Use a high-efficiency panel heater with a thermostat in a small, closed room. Better yet, insulate that room.
How to heat your house for free (or nearly)?
better windows (uPVC, low E double glazing)
Insulation R3-6 around the house
airtightness (aim for less than 3ACH)
ventilation (mechanical, if you can balanced - tiny little trickle vents in your windows are not big enough for ventilation through extracts!)
thermal bridge free design (important when youre working with steel and concrete)
Calculated Example: Is a High-Performance Window Better Than a Heat Pump?
Comparing insulation upgrade vs. new heating system
Say you’ve got $3,000 to spend:
Option 1: Heat Pump Installation
Cost: $3,000
Output: Up to 5kW
COP: 4.5 (Coefficient of Performance)
Delivered heat: 2,500 kWh/year
Electricity used: ~555 kWh/year
Operating cost (@$0.30/kWh): $166/year
Heating value: ~$750 worth of delivered heat
Option 2: High-Performance Window Upgrade
Area: 10m²
Upgrade from U-value 2.8 to 1.2
Estimated energy savings: ~600 kWh/year
Cost savings (@$0.30/kWh): ~$180/year
Improved comfort and reduced condensation risk
Payback and Value Comparison
Heat pump: Larger immediate gain in delivered heat for comfort
Windows: Lower energy use and ongoing savings, plus improved thermal performance year-round
BUT: If the house is leaky or poorly insulated, the heat pump has to work harder. That reduces real efficiency and increases running costs. Windows reduce demand permanently.
When is it smarter to spend on building fabric?
Always start with insulation and airtightness first—especially in roofs, subfloors, and windows. Heating adds comfort, but efficiency is lost without thermal performance.
Our Recommendation: Start with the Building Envelope
Why airtightness and insulation come first
Without a well-sealed envelope, every kWh of heat leaks out. That’s why we start every project with a blower door test and energy model.
The role of energy modelling in finding the most cost-effective path
Our modelling shows you:
Where your heat is escaping
Which upgrades offer the best payback
How to size your heating system properly
