How to Keep a House Warm in Winter? Winter in New Zealand can be deceptively harsh. While we rarely see the deep freezes of the Northern Hemisphere, our climate is cold, damp, and long — and many Kiwi homes simply weren't built to hold heat. Older weatherboard houses, single-glazed windows, and minimal insulation mean that a lot of homes struggle to stay warm and dry once the temperature drops, particularly through Otago, Southland, Canterbury, and the Central Plateau.
The good news is that you don't have to run the heat pump flat out and watch your power bill climb to stay comfortable. With a handful of smart, low-cost changes, you can keep your home warm, dry, and healthy right through the coldest months. The tips below draw on advice from New Zealand energy and building experts, and they're ideal if you're looking for cost-effective, eco-conscious ways to warm your home.
The World Health Organization recommends keeping living areas at a minimum of 18°C to protect against respiratory and cardiovascular strain — and that's also the benchmark behind New Zealand's Healthy Homes Standards for rental properties. Here are 12 practical ways to hit that target without wasting energy.
How to Keep a House Warm in Winter?
1. Seal the draughts first
A surprising amount of heat escapes through small gaps under doors, around window frames, and through unused vents and old fireplaces. Sealing these leaks is the cheapest and most effective first step. Use weatherstripping or a good silicone sealant around windows and door frames, and fit a door snake or brush seal to exterior doors. In a pinch, a rolled towel under the door works too.
2. Let the winter sun do the work
Sunlight is free heat. Because New Zealand sits in the Southern Hemisphere, it's your north-facing windows and rooms that catch the most sun. Open the curtains and blinds on those windows during the day to let the sunlight warm your floors and furniture, then close everything the moment the sun goes down to trap that warmth inside.
3. Hang thick, thermal-lined curtains
Windows are one of the biggest sources of heat loss in a Kiwi home, especially if they're single-glazed. Thermal-backed curtains that reach below the sill — ideally right to the floor — can dramatically cut the heat escaping overnight. Make sure they sit snugly against the wall at the top so warm air can't slip down behind them.
4. Lay down rugs on bare floors
Timber and tile floors feel lovely in summer but leak heat and feel icy in winter. Area rugs and carpet add a layer of insulation, reduce heat loss through the floor, and make a room feel noticeably warmer underfoot — a cheap fix that makes a real difference in older villas and bungalows.
5. Prioritise insulation
Insulation is the single most important factor in keeping a home warm. Ceiling and underfloor insulation are the highest-value upgrades for most New Zealand homes, and they're often the first thing landlords must address under the Healthy Homes Standards. If you own your home and meet the criteria, it's worth checking whether you qualify for a grant through EECA's Warmer Kiwi Homes programme, which can cover a large share of insulation and heating costs.
6. Ventilate to beat dampness and mould
This one's especially important here: New Zealand homes are prone to damp and mould, and moist air feels colder and is harder to heat. Open windows for 15–30 minutes a day, even when it's cold outside, and run extractor fans while cooking or showering. Dry air warms faster and holds heat better — and you'll protect your family's health and your walls at the same time.
7. Use zone heating
You don't need to heat the whole house to the same temperature. Concentrate your heating on the rooms you're actually using — the lounge in the evening, the bedroom before sleep — and keep doors closed to stop warm air drifting into unused spaces. A heat pump set to a sensible temperature in the main living area is usually far more efficient than trying to warm every room at once.
8. Reverse your ceiling fan
Warm air rises and gathers near the ceiling, out of reach. Most modern ceiling fans have a reverse switch — run the fan slowly in reverse (clockwise) during winter to gently push that warm air back down into the room. It's a small trick that lets you feel warmer without turning the heating up.
9. Rearrange your furniture
Where you sit matters. Pull sofas and chairs away from cold external walls and windows and closer to internal walls or into the path of the winter sun. Also make sure furniture, curtains, or rugs aren't blocking heat pump outlets or heater vents, which stops warm air circulating properly.
10. Use electric blankets safely
An electric blanket is a low-cost way to warm the bed before you get in. Only use it to pre-warm the bed and switch it off before you fall asleep — never leave one running overnight. Check the cord for fraying or damage each season and always follow the manufacturer's safety instructions.
11. Heat safely and check your alarms
Place portable heaters on a flat, stable surface, keep them at least a metre clear of curtains, bedding, and furniture, and never leave them running when you're out or asleep. While you're at it, test your smoke alarms — every home should have working alarms, and they need testing monthly with batteries replaced once a year.
12. Keep the heat on during a power cut
Winter storms regularly knock out power across New Zealand, and an outage on a cold night is more than an inconvenience. A portable power station gives you peace of mind — it can safely run essentials like lights, Wi-Fi, an electric blanket, or a small heater until the grid comes back. Something like the EcoFlow DELTA Pro 3, with 4000W output and up to 12kWh of expandable capacity, can keep most household essentials running through an extended outage, while a more compact unit from the EcoFlow DELTA series suits smaller homes or shorter interruptions. Charge it from solar during the day and you've got clean, free backup power ready to go when you need it most.
Staying warm shouldn't cost the earth
Keeping your home warm through a New Zealand winter doesn't have to mean sky-high power bills or wasteful heating. By making the most of the winter sun, sealing draughts, insulating properly, keeping your home dry, and heating smartly, you can create a warm, healthy home even on the coldest Southland nights. And if you're worried about the power going out, a portable power station means the heat, lights, and internet stay on regardless of the weather.
If you've been wondering how to keep your house warm this winter, start with the simple steps today — seal a draught, open the north-facing curtains, throw a rug down — and you'll feel the difference by tomorrow night.
