The short answer: under the Healthy Homes insulation standard, the minimum ceiling insulation R-value is generally R2.9 in zones 1 and 2 and R3.3 in zone 3. Existing insulation must also be in reasonable condition, with no mould, dampness, damage or gaps.

That answer is not enough for every rental. A landlord also needs to check when the property was consented, whether later consented renovation work brought the 2021 Building Code into play, whether an older-insulation or partial exemption applies, and what evidence supports the compliance statement.

This guide is general information for New Zealand landlords. It is not legal, building, insulation, tax, accounting, or tenancy-dispute advice. Use the Tenancy Services insulation tool, the latest official guidance, and a qualified insulation professional for the property itself.

What ceiling insulation R-value does a New Zealand rental need?

For a rental assessed under the standard Healthy Homes climate-zone map, the minimum R-values are:

| Healthy Homes climate zone | Ceiling insulation | Underfloor insulation | |---|---:|---:| | Zone 1 | R2.9 | R1.3 | | Zone 2 | R2.9 | R1.3 | | Zone 3 | R3.3 | R1.3 |

Tenancy Services describes zone 1 as the top of the North Island, zone 2 as coastal areas of the North Island, and zone 3 as the central North Island and the whole South Island. Use the official map or insulation tool rather than choosing a zone from memory.

R-value measures resistance to heat flow. A higher R-value means the insulation resists heat flow better. It does not prove that the material is still correctly installed or in reasonable condition.

Do the same R-values apply to every rental?

No. The R2.9 and R3.3 figures are the Healthy Homes minimums commonly used for existing rentals, but the property's building and consent history matters.

Tenancy Services says new builds and renovated properties requiring consent need to meet the minimum insulation requirements in the 2021 Building Code update. Those Building Code requirements exceed the Healthy Homes insulation minimums. An existing rental that is only having insulation installed or topped up does not automatically need to meet the 2021 Building Code figures, provided the property is not undergoing renovation work that requires building consent.

This distinction matters because New Zealand's current Building Code uses six climate zones, while the Healthy Homes guidance for older properties uses three. Do not copy a Building Code roof number into a Healthy Homes record, or vice versa, without checking which rule applies to the work and property.

How should a landlord check an existing ceiling R-value?

A reliable check follows five steps.

1. Confirm the property and consent history

Start with the rental address, original building consent date, and any later consented renovation work. Council property files, code compliance certificates, renovation records, and installer paperwork can help establish which standard applies.

If a renovation required building consent, check the consented insulation specification and completion documents. Do not assume the older Healthy Homes minimum is the right benchmark for new consented work.

2. Confirm the climate zone

Use the Tenancy Services map or insulation tool for the Healthy Homes check. Record the zone in the property file with the date it was checked.

The useful record is not just zone 2. It should say which official source was used, when it was checked, and which ceiling areas were assessed.

3. Find the installation evidence

For new insulation, the product packaging or manufacturer's instructions should state the installed R-value. For existing insulation, evidence may include:

a product label stapled to a beam
an installer certificate
an invoice that identifies the product and installed R-value
council building records
an insulation assessment
dated photos and measurements

If the R-value is unknown, record it as unknown. Unknown - professional assessment required is more useful than a confident guess based on colour, thickness, or memory.

4. Check condition and coverage

The insulation must still be in reasonable condition. Tenancy Services says there should be no mould, dampness, damage or gaps.

A condition check should look for:

compressed or flattened sections
material moved after electrical, plumbing, roofing, or ceiling work
wet or mouldy insulation
pest damage
gaps around hatches, edges, additions, and awkward corners
incomplete coverage above domestic living spaces
two layers that have separated or no longer sit correctly

Do not enter a ceiling space if access is unsafe. A qualified installer or assessor should handle uncertain or hazardous access.

5. Match the result to the compliance record

The property file should connect the R-value and condition check to the tenancy's Healthy Homes statement. Keep the evidence that explains:

the installation date, if known
the last inspection date
the installed R-value or measured thickness
the climate zone and rule used
any area that is not insulated and why
any exemption relied on
follow-up work and the updated result

The current regulations require landlords to retain documents that relate to Healthy Homes compliance. A number in a spreadsheet without the supporting record is a weak position.

Is 120 mm of old ceiling insulation enough?

Not as a universal rule.

Tenancy Services says existing ceiling insulation installed before 1 July 2016 must be at least 120 mm thick. Ceiling insulation below 120 mm can still be acceptable if the landlord can prove that it met the relevant minimum R-value when installed and that its thickness has not degraded by more than 30%.

The official regulations also contain transitional provisions for certain pre-1 July 2016 ceiling insulation. Those provisions depend on more than a tape-measure reading, including the earlier compliance position and the statement recorded for the tenancy.

Treat 120 mm as a prompt to check the official pathway, not as a stand-alone certificate of compliance. Condition, coverage, installation, previous compliance, and evidence still matter.

What changed for limited ceiling cavities in September 2025?

On 25 September 2025, an amendment added a narrow partial exemption for certain ceiling insulation situations.

Tenancy Services explains that the change can apply where a rental was previously compliant under the 2016 insulation regulations but a low-pitched roof or limited ceiling cavity prevents the property from meeting the current ceiling-insulation standard. The property must compensate with higher levels of floor, wall, and window insulation that meet the relevant Building Code standard. The applicable building-consent dates also depend on the climate zone.

This is not a blanket exemption for hard-to-access roofs. It has specific eligibility and evidence requirements. A landlord considering it should:

read the current Tenancy Services insulation standard
check regulation 19A and regulation 35 in the latest Residential Tenancies (Healthy Homes Standards) Regulations 2019
obtain the relevant building and previous-compliance documents
use a qualified professional to assess the ceiling constraint and compensating insulation
update the Healthy Homes compliance statement with the required exemption information

If the evidence does not establish the exemption, do not describe the property as exempt.

When should ceiling insulation be re-checked?

Re-check the insulation and its record when something could have changed either one.

Useful triggers include:

before starting a new tenancy
after roof leaks or storm damage
after electrical, plumbing, roofing, pest, or ceiling work
when a tenant reports cold rooms, condensation, dampness, or mould
before relying on an old assessor report
when invoices, photos, or installation details are missing
when a renovation or alteration may require building consent
when an exemption is being relied on and its supporting facts may have changed

The aim is not to order an unnecessary full assessment every year. It is to notice the events that can make an old record unreliable.

What should the ceiling insulation record contain?

For each rental, keep one decision-ready record with:

property address
original and relevant later consent dates
Healthy Homes climate zone
ceiling areas covered by the check
insulation type and product, if known
installed R-value or measured thickness
installation and inspection dates, if known
representative photos
installer or assessor details
invoices, certificates, and council records
condition issues and remedial work
inaccessible areas and the professional reason access was impracticable
exemption basis and supporting documents
the current Healthy Homes statement
the next action, owner, and due date

This turns the file from a collection of documents into a usable answer: what is installed, what proves it, what changed, and what needs doing next?

How does Keel help with insulation records?

Keel does not assess insulation, certify a rental, or replace Tenancy Services or a qualified professional.

Keel keeps the operating record around the work attached to the rental. For example, a tenant reports condensation after roofing work. Skip can help organise the report and draft the next step for the landlord to approve. The landlord can review the earlier insulation record, request an assessment, keep the photos and invoice with the issue, and record whether the Healthy Homes statement needs updating.

The useful part is continuity. The tenant report, old R-value, assessor evidence, approved work, and current decision do not have to live in five different inboxes.

If the evidence for a rental is spread across email, phone photos, PDFs, and memory, see how Keel keeps Healthy Homes work together.

Ceiling insulation R-value checklist for landlords

Before relying on the record, confirm:

[ ] Which standard applies to the property and work
[ ] The correct Healthy Homes climate zone, where relevant
[ ] The ceiling R-value or valid older-insulation pathway
[ ] Current condition, coverage, and safe access
[ ] Evidence for any exemption
[ ] Installer, assessor, invoice, photo, and council records
[ ] The Healthy Homes compliance statement reflects the current position
[ ] The next action has an owner and due date

The R-value is the searchable question. The property-specific answer is the number, condition, rule, and evidence together.

Official sources

Tenancy Services, Insulation standard, updated 25 September 2025.
New Zealand Legislation, Residential Tenancies (Healthy Homes Standards) Regulations 2019, latest version as at 25 September 2025.
New Zealand Legislation, Residential Tenancies (Healthy Homes Standards) Amendment Regulations 2025.
Tenancy Services, Healthy Homes compliance.
Tenancy Services, Healthy Homes compliance statement.

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