As of 1 July 2025, all private rental properties in New Zealand must comply with the Healthy Homes Standards under the Residential Tenancies Act. The standards cover five areas: heating, insulation, ventilation, moisture ingress and drainage, and draught stopping. Of these, the moisture ingress and drainage standard has the most direct plumbing implications for landlords.
Requirements include efficient stormwater, surface water, and groundwater drainage; functioning gutters, downpipes, and drains; and a ground moisture barrier in any property with an enclosed sub-floor. Any restricted plumbing or drainage work must be carried out by a licensed plumber or drainlayer. Landlords who fail to comply risk exemplary damages through the Tenancy Tribunal. Every new or renewed tenancy agreement must include a compliance statement reflecting the property’s current status against all five standards.
If you own a rental property in New Zealand and you are not certain it meets the Healthy Homes Standards, you are now in breach of the law. Since 1 July 2025, full compliance has been mandatory for all private rentals across the country, with no grace periods remaining for standard residential tenancies.
The Residential Tenancies Healthy Homes Standards Regulations have been through several staged rollouts since they took effect in 2019, but those stages are now complete. Every landlord, in every region, is expected to have their house in order.
For many landlords, the practical question is not whether the standards apply but what they actually require in terms of physical work on the property. Let’s dive in and take a more in-depth look at the plumbing-related obligations within the standards and what you need to know before your next tenancy agreement is signed.
The standards are built around five pillars, each with specific and enforceable minimum requirements:
Each of these has its own set of specific rules, exemptions, and documentation requirements. From the viewpoint of experienced local plumbers, this post focuses most closely on moisture and drainage because it is where a licensed plumber or drainlayer is most likely to be required, and where landlords with older housing stock are most often caught short.
The Healthy Homes moisture ingress and drainage standard requires that rental properties have efficient drainage for the removal of stormwater, surface water, and groundwater, including an appropriate outfall. Specifically, the drainage system must include functioning gutters, downpipes, and drains.
For properties with an enclosed sub-floor space, a ground moisture barrier must be installed unless it is genuinely not practicable to do so. The barrier must meet the specifications set out in section 8 of the NZS 4246:2016, or achieve an equivalent vapour resistance rating. Barriers that were installed before 1 July 2019 are not required to meet that standard, but they must be free of significant holes or tears that allow moisture through.
Exactly what it sounds like – it’s a space beneath the floor where the ground is not directly exposed to the open air. A very large number of older homes in NZ have this type of construction, particularly properties built before the 1980s with timber floors. For landlords of these properties, the ground moisture barrier requirement is not optional.
As a licensed plumber with years of experience across rental properties and residential builds, Whitehead Plumbing and Gas in Christchurch puts it “The moisture standard catches more landlords off guard than anything else. People think compliance means putting in a heat pump and calling it done. But if there is water pooling under the floor or the gutters are blocked and overflowing against the foundation, that property is non-compliant regardless of how warm the lounge is.”
The ventilation standard is primarily an architectural and electrical concern, but it touches plumbing work in one specific and important way – bathroom and kitchen extractor fans.
The standard requires that kitchens and bathrooms have extractor fans capable of venting moisture-laden air to the outside. A fan that simply recirculates air inside the room or discharges into a ceiling void does not meet the requirement. This means landlords who have older, internal-discharge fans installed will need to have them replaced or redirected.
Depending on the layout of the property, rerouting an extractor fan duct may involve working in wall cavities or through rooflines. While the fan installation itself may be electrical work, the penetrations and ducting can overlap with building and plumbing trades. Getting a plumber involved early in an extractor fan upgrade can save time and prevent damage to pipes or drainage lines running through the same wall cavities.
This is a point that a number of landlords misunderstand. The standards allow landlords to carry out some of the compliance work themselves, but there are clear restrictions.
Restricted plumbing and drainage work must be carried out by a licensed plumber or drainlayer. This is a requirement under the Plumbers, Gasfitters, and Drainlayers Act 2006.
In plain terms, it includes any work that connects to or modifies the drainage system, any work on the stormwater or wastewater network, and repairs or modifications to gutters and downpipes where those connect to the drainage system rather than simply discharging to open ground.
A ground moisture barrier installation does not typically require a licensed plumber, but if the subfloor inspection reveals leaking pipes above the barrier location, those pipes must be repaired by a licensed tradesperson before the barrier is installed. Attempting to install a barrier over leaking plumbing simply traps the problem.
“We often get called into subfloor jobs regularly where the homeowner or property manager has tried to fix things themselves and made it worse,” says expert Christchurch plumbers Whitehead plumbing. “Water finds its way. If there is a drain issue or a pipe weeping under the floor, no moisture barrier in the world will solve it. You need to fix the source first, and that is licensed work.”
Since 1 December 2020, all new, varied, or renewed tenancy agreements have been required to include a Healthy Homes compliance statement. This is a formal declaration of the property’s current level of compliance against all five standards.
This is not a self-assessment that can be vague or aspirational. The statement must accurately reflect the actual condition of the property at the time the agreement is signed. If the property has a blocked downpipe, a missing ground moisture barrier, or a bathroom fan that discharges into the ceiling, the landlord cannot simply declare compliance and hope for the best.
If a landlord signs a compliance statement and the property does not actually meet the standards, this can be used as evidence in Tenancy Tribunal proceedings. The Tribunal can award exemplary damages per breach of the Residential Tenancies Act, and a deliberately inaccurate compliance statement compounds the legal exposure significantly.
For landlords, this makes a professional property assessment before signing a new tenancy agreement a sound investment. A licensed plumber can inspect the drainage, guttering, and subfloor condition and provide written documentation of compliance or of the work required to reach it.
NZ’s housing stock presents some particular challenges when it comes to Healthy Homes compliance. A number of factors specific to the region create recurring plumbing and drainage problems in rental properties.
Older properties in cities like Christchurch, Dunedin and Wellington typically have enclosed subfloor spaces and aging guttering systems. It is not unusual to inspect these properties and find downpipes that are cracked or misaligned at the base, discharging water against the foundation wall rather than into the stormwater system. Over time, this leads to exactly the kind of damp subfloor environment that the moisture standard is designed to prevent.
In some areas of NZ, clay-heavy soils also retain water after rainfall and contribute to groundwater pressure against subfloor spaces in lower-lying areas. Properties in flat suburbs, particularly those near waterways or with limited site drainage, are more likely to require drainage improvements to meet the standard.
Post-earthquake repairs carried out in the early 2010s in Christchurch also pose their own unique challenges, as remediation work was done quickly and at scale. In some cases, the drainage and subfloor repairs completed as part of that work are now showing signs of secondary failure. Properties that were signed off as repaired a decade ago may now have drainage issues that did not exist at the time but have developed since.
If you have not already confirmed that your rental property meets the Healthy Homes Standards, the starting point is a full inspection before your next tenancy begins or is renewed.
If work is required, it needs to be completed by a licensed plumber or drainlayer for any components that fall under restricted work. Keep records of all work completed, including invoices and any relevant certificates. These records form part of your evidence of compliance should a dispute ever arise.
Your compliance statement in the tenancy agreement should reflect the actual outcome of that inspection and any work completed, not a general intention to comply at some future point.
Meeting the standards at the start of a tenancy is not the end of the obligation. Landlords are required to ensure their properties continue to meet the standards over time. If a tenant notifies you of a drainage problem, a blocked downpipe, or moisture in the subfloor, you are required to arrange repairs within a reasonable timeframe.
What counts as reasonable will depend on the severity of the issue and the availability of tradespeople. Christchurch has a busy building and trades sector, and booking a licensed plumber can take time. The best protection against being found non-compliant during a tenancy is to start the process as soon as you are made aware of a problem, keep the tenant updated, and keep a written record of every step taken.
If you own a rental property in Christchurch and need a drainage inspection or moisture assessment to confirm your Healthy Homes compliance, contact the Whitehead plumbing team. We work with landlords and property managers across Canterbury to assess, document, and complete any restricted plumbing or drainage work required.
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