Insulation Requirements for Landlords NZ

Why Insulation Matters

Insulation reduces heat loss, keeping properties warmer in winter and cooler in summer. Well-insulated homes are cheaper to heat, more comfortable to live in, and less prone to moisture problems that cause mould and mildew.

For landlords, good insulation means happier tenants, lower turnover, and a property that maintains its value. Meeting the legal requirements also protects you from penalties and potential claims.

Where Insulation Is Required

Under the Healthy Homes Standards, you must have insulation in two key areas:

Wall insulation is not currently required under the Healthy Homes Standards, though it significantly improves a property's thermal performance. If your property was built after 1978, it likely has some wall insulation as this became part of the Building Code.

Minimum R-Values

R-value measures insulation's thermal resistance; the higher the R-value, the better the insulation performs. The minimum R-values required depend on your property's climate zone.

If you are unsure which zone your property is in, the MBIE website has detailed maps showing zone boundaries.

Existing Insulation

If your property already has insulation, it may not need to be replaced. Existing insulation can comply if:

• It was installed according to the Building Code or manufacturer requirements at the time
• It is still in reasonable condition (not significantly degraded, damp, or damaged)
• It has no significant gaps

For ceiling insulation installed before 1 July 2016, the minimum thickness requirements are lower. For example, in zones 1 and 2, existing ceiling insulation must be at least 120mm thick (compared to the R2.9 requirement for new insulation).

Exceptions and Exemptions

Some situations make insulation installation impractical or unnecessary:

If an exemption applies, you must still document this in your compliance statement and explain why insulation has not been installed.

Installation Considerations

Insulation must be installed correctly to be effective. Poor installation can significantly reduce performance and even cause problems.

Many insulation installers offer assessments and can provide a compliance report once work is complete. Keep all documentation for your records.

Related: Healthy Homes Standards for Landlords

Compliance Statements

You must include insulation details in the Healthy Homes compliance statement provided to your tenant. This statement must be included with or attached to the tenancy agreement.

The statement should specify what insulation is installed, where it is located, and its type and thickness or R-value. If any exemptions apply, these must also be noted.

Costs and Funding

Insulation costs vary depending on property size, accessibility, and existing conditions. As a rough guide:

• Ceiling insulation: $1,500 to $3,500 for an average home
• Underfloor insulation: $2,000 to $4,500 for an average home
• Combined packages may offer better value

While the government's Warmer Kiwi Homes programme was primarily for owner-occupiers, some subsidies may still be available. Check with EECA (Energy Efficiency and Conservation Authority) for current funding options.

The Bottom Line

The 1 July 2025 compliance deadline has passed. All private rental properties must now meet the Healthy Homes insulation standards. There are no remaining transitional periods or grace periods — if your property does not comply, you are in breach of the law and exposed to Tenancy Tribunal orders and penalties.

If you have not yet ensured your property meets the insulation requirements, act immediately. Understanding the requirements, checking your existing insulation, and addressing any gaps protects you legally and improves your property's quality.

Well-insulated properties attract better tenants, command higher rents, and cost less to maintain over time. While there is an upfront cost to meet the standards, it is an investment in both compliance and property value.