Water moves out, not in.
Guttering, drainage, a ground sheet.
Every NZ rental needs working guttering, downpipes, and stormwater drainage. Where the property has an enclosed sub-floor, a ground moisture barrier is required.
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What the standard requires
Rental properties must have efficient drainage for the removal of stormwater, surface water, and ground water. That includes working guttering, downpipes, and a stormwater drainage system that moves water away from the building.
Where the property has an enclosed sub floor (most timber framed houses), a ground moisture barrier is required. The barrier sits on the ground under the house and stops moisture from the soil rising into the floor structure. Without it, sub floor air carries that moisture into the living space.
Tenants have a duty to report blocked guttering, broken downpipes, leaks in pipes, and damp in walls or ceilings promptly. Landlords cannot fix what they do not know about.
What to look for in your flat
- Clean, intact guttering with no plants, leaves, or visible sagging.
- Downpipes that connect to the stormwater system, not just dumping water at the foundation.
- No standing water around the foundation after rain.
- No damp patches, water stains, or peeling paint on walls or ceilings.
- If you can safely look under the house, a polythene barrier covering the soil under the building (a black or clear plastic sheet, typically taped at the joins).
- Skirting boards and lower wall sections that are not swollen, cracked, or stained.
What to do if it is not in place
Compliance status
Private rentals were required to meet the moisture and drainage standard by 1 July 2025. Ground moisture barrier installation in enclosed sub floors is part of that requirement.
Common exemptions
Ground moisture barriers are only required where the sub floor is enclosed and accessible. Properties built on concrete slabs, or with fully open sub floors, are exempt from that part of the standard. For the full list, see Tenancy Services on Healthy Homes exemptions.
The other four standards
Heating
A fixed heater in the main living room, sized to warm the space properly. Portable heaters do not count.
Insulation
Ceiling and underfloor insulation that meets the minimum specification for your part of the country.
Ventilation
An openable window or door in every habitable room, plus extractor fans in kitchens and bathrooms.
Draught stopping
Unreasonable gaps in walls, ceilings, windows, floors, and doors blocked so they do not cause noticeable draughts.
Sources
This page summarises the moisture and drainage standard as published by Tenancy Services and the Residential Tenancies Act 1986. For the authoritative wording, see Tenancy Services on the moisture and drainage standard.
Last updated . Flatchat is not your lawyer; if your tenancy is heading to the Tribunal, talk to Tenancy Services or a qualified advocate.
See what tenants said.
Before you sign.
Damp under a house is invisible until it shows up on the skirting boards. Tenant reviews on Flatchat call out the flats that smell musty all winter, not just the ones with obvious leaks.