Preparing your rental property for winter: a NZ landlord's checklist

Why winter preparation matters

New Zealand's winters are wet, cold, and tough on rental properties. From Southland to Auckland, the combination of low temperatures, high rainfall, and older housing stock means that properties left unprepared are prone to moisture damage, mould, tenant complaints, and costly emergency repairs.

Preparing your rental for winter isn't just good property management — it's a legal requirement in many respects. The Healthy Homes Standards mandate minimum levels of heating, insulation, ventilation, moisture ingress protection, and draught stopping for all private rental properties. If your property doesn't meet these standards, you're already non-compliant.

This checklist covers the practical steps to get your rental through winter in good shape.

Heating

Check the fixed heater

The Healthy Homes heating standard requires a fixed heater in the main living room capable of heating the space to at least 18°C. Before winter:

• Service heat pumps annually. Clean the filters (monthly during heavy use), check the outdoor unit is clear of debris, and book a professional service. A poorly maintained heat pump loses efficiency significantly.
• Test wood burners and flues. If the property has a wood burner, ensure the flue is clean and the firebox is in good condition. A chimney sweep costs $100–$200 and should be done annually.
• Check that the heater meets the standard. If you installed the heater years ago, confirm it still has the capacity required for the room. MBIE's online calculator is free and takes five minutes.
• Replace non-compliant heaters. Unflued gas heaters and undersized portable electric heaters do not meet the standard. If your property still has one of these as the primary heat source, it needs to be replaced.

Tenant communication

Remind tenants how to operate the heating system efficiently. Many tenants — particularly those new to heat pumps — don't know the optimal settings. A brief email with guidance (e.g., "Set to heating mode at 18–21°C, don't turn it on and off repeatedly") can prevent complaints and reduce running costs.

Insulation

Ceiling and underfloor

The Healthy Homes insulation standard requires ceiling and underfloor insulation that meets or exceeds 2008 Building Code levels.

Before winter, check:

• That existing insulation hasn't been displaced, compressed, or damaged — especially if any work has been done in the ceiling space (electricians and plumbers sometimes move insulation and don't replace it)
• That underfloor insulation is still properly secured and hasn't sagged or fallen
• Whether there are any gaps in coverage — insulation is only effective if it covers the entire area without breaks

If you haven't had an insulation inspection in the last two to three years, it's worth getting one. EECA's Warmer Kiwi Homes programme may still offer subsidies depending on the property's location and the owner's circumstances.

Hot water cylinder

If the property has a hot water cylinder, check that it has a cylinder wrap (insulation jacket) if it's located in an unheated space. This is a cheap, simple upgrade that reduces heat loss and energy costs.

Gutters and drainage

Blocked gutters are one of the leading causes of water damage in New Zealand homes. During autumn and winter, leaves, moss, and debris accumulate quickly.

Gutter checklist

• Clean all gutters and downpipes before winter begins — and again mid-winter if the property is near trees
• Check for sagging or damaged gutters that allow water to overflow onto fascia boards, causing rot
• Ensure downpipes are connected and directing water away from the building's foundation
• Clear ground-level drainage channels around the property, including any subfloor drainage

Subfloor drainage

The Healthy Homes drainage and moisture ingress standard requires that the subfloor is reasonably dry. If the property has a subfloor space:

• Check for standing water or excessive dampness
• Ensure any drainage systems are functioning
• Confirm that ground cover polythene is in place and intact (required where the ground moisture level exceeds acceptable limits)

Ventilation

Good ventilation is essential for controlling moisture — and it's a Healthy Homes requirement. The standard requires adequate openable windows in living areas, bedrooms, kitchens, and bathrooms, plus an extractor fan in at least one bathroom and the kitchen.

Pre-winter checks

• Test extractor fans in the kitchen and bathroom. Clean the grilles, check they're actually extracting air (hold a tissue near the fan — it should be drawn towards it), and replace any that aren't working.
• Check window latches and stays. Tenants need to be able to open windows for ventilation, even in winter. Broken stays or seized latches prevent this.
• Consider a ventilation system. In persistently damp properties, a positive pressure ventilation system (like HRV or SmartVent) or a balanced system can make a significant difference to indoor moisture levels.

Tenant guidance

Moisture in winter is a shared responsibility. Encourage tenants to:

• Use extractor fans when cooking and showering
• Open windows for 10–15 minutes daily, even in cold weather
• Avoid drying clothes indoors without ventilation
• Wipe down condensation on windows

A brief guide provided at the start of winter can help prevent mould issues that lead to complaints and potential Tribunal claims.

Moisture and mould

Mould is one of the most common issues in NZ rental properties during winter. It's a health hazard, a frequent cause of tenant complaints, and can result in Tribunal orders if it's caused by a building deficiency.

Landlord responsibilities

• Address any water ingress — leaking roofs, windows, or plumbing
• Ensure the property has adequate ventilation and heating
• Fix any drainage issues that cause damp subfloors
• Treat and remove existing mould caused by building faults before winter

What's the tenant's responsibility?

If the property is well maintained, properly insulated, and has adequate heating and ventilation, and the tenant's lifestyle choices (e.g., drying laundry indoors with windows closed, never using extractor fans) cause mould — that's generally the tenant's responsibility. But the landlord must be able to demonstrate that the building itself is not the cause.

Practical tip: Document the property's condition, including any mould-prone areas, during your routine inspections. Photographs with dates are your best evidence.

Hot water

• Check the hot water system is working efficiently. If the property has a hot water cylinder, ensure the thermostat is set to 60°C at the cylinder to prevent legionella bacteria growth.
• Insulate exposed hot water pipes in unheated areas (subfloor, roof space) to prevent heat loss and reduce the risk of freezing in very cold regions.
• Test the tempering valve — this should limit the temperature at the tap to no more than 55°C to prevent scalding.

Exterior and garden

• Check the roof for damaged, loose, or missing tiles or iron sheets. Even small gaps can cause significant water damage over a wet winter.
• Trim overhanging branches that could fall in storms or deposit leaves into gutters.
• Clear paths and driveways of moss and algae to reduce slip hazards. A waterblaster or moss treatment applied in autumn makes a big difference.
• Check fencing for damage or instability, particularly if the property is exposed to prevailing winds.
• Ensure exterior lighting works — shorter days mean tenants arrive home in the dark. Functional exterior lighting is a safety basic.

Draught stopping

The Healthy Homes draught stopping standard requires that all external doors and windows can be closed and that any unnecessary openings are blocked.

Quick checks:

• Do all external doors close and latch properly? Check for warping, especially in older wooden doors.
• Are there visible gaps around windows, doors, or where pipes and cables enter the building?
• Do all windows close fully and have functional latches?
• Are any unused chimneys or fireplaces properly sealed or fitted with a damper?

Draught stopping is one of the cheapest Healthy Homes fixes — foam tape, door snakes, and sealant can make a noticeable difference for under $100.

Your winter preparation timeline

| When | Action | |------|--------| | Late February – March | Book heat pump service, gutter clean, and insulation check | | March – April | Complete exterior maintenance (roof, paths, fencing, garden) | | April | Test extractor fans, check draught stopping, inspect subfloor | | April – May | Send tenant winter guidance (heating, ventilation, moisture) | | Ongoing (May – September) | Respond promptly to maintenance requests, monitor for mould |

Bringing it all together

Winter preparation is about prevention. The cost of a gutter clean, a heat pump service, and a few rolls of draught tape is trivial compared to the cost of water damage, mould remediation, or a Tribunal claim for non-compliance with Healthy Homes Standards.

Tools like keel can help you schedule seasonal maintenance tasks and track compliance across your properties, so nothing gets overlooked. But the real key is starting early — March and April are the time to act, not June when the damage has already begun.