NZS 4306 is the New Zealand Standard for residential property inspections. When a buyer asks for a pre-purchase building report, this is the standard a proper report is written to. It sets out what the inspector must examine and how the report should be structured, so buyers get a consistent, comparable picture.

What does an NZS 4306 building report cover?

A report to NZS 4306 covers the building systematically — the site and grounds, exterior cladding and joinery, the roof and roof space, the subfloor, interior rooms and wet areas, and the accessible services — noting the condition of each and any defects found. It also states its own limitations: what could not be accessed or assessed, and where a specialist is needed.

Why does a building report say 'further investigation by a specialist'?

A visual inspection has limits. Where a matter is beyond the scope of a visual, non-invasive inspection — for example wiring, weathertightness, or hazardous materials — a good report recommends further investigation by a specialist. That is an honest outcome, not a weak one. It is a recommendation to obtain a specialist assessment, not a finding that a defect does or does not exist.

What is excluded from a pre-purchase building inspection?

A pre-purchase inspection is typically visual and non-invasive and excludes a building-code compliance assessment, structural or geotechnical engineering, a weathertightness guarantee, specialist testing of electrical, gas or plumbing services, hazardous-materials testing such as asbestos or methamphetamine, pest inspection, and property valuation. Each of these requires a separately engaged specialist.

What makes a building report defensible?

A defensible report has a clearly stated scope, evidence attached to each finding such as photos with time and location, honest limitations and specialist referrals, and a published version that cannot be quietly edited after the fact. Those are the things that make a report hold up if it is ever questioned.

What must be in an NZS 4306 pre-purchase building report

In short

NZS 4306 is the standard a proper pre-purchase building report is written to. It covers the building systematically — exterior, roof, subfloor, interior and services — records the condition and defects of each, and clearly states its own limitations: what couldn't be accessed, and where a specialist is needed. A report that flags rather than fabricates is the strong one.

When a buyer asks for a "pre-purchase building report," NZS 4306:2005 is the New Zealand Standard a proper one is written to. It sets out what the inspector must examine and how the report should be structured — so buyers get a consistent, comparable picture rather than one inspector's ad-hoc notes.

What NZS 4306 is, and why buyers should insist on it

NZS 4306 is the New Zealand Standard for residential property inspections. Its value to a buyer is consistency: two reports written to the standard cover the same ground in the same structure, so you can actually compare them and know nothing major was skipped. Asking for a report "to NZS 4306" is the simplest way for a buyer to set that expectation up front.

What the report has to cover

A report to NZS 4306 works through the building systematically, noting the condition of each part and any defects found:

The site and grounds immediately around the building.
The exterior — cladding, joinery and visible weatherproofing.
The roof and roof space, where safely accessible.
The subfloor, where there's access.
The interior — rooms and wet areas.
The accessible services — plumbing fixtures, the switchboard and hot-water cylinder, visually.

Crucially, it also records its own limitations: the specific areas that couldn't be accessed or assessed on the day, and why.

Limitations and "further investigation" outcomes

A pre-purchase inspection is visual and non-invasive — the inspector observes what can be seen and safely accessed, without dismantling the building or moving stored goods. So the report will list areas it couldn't inspect, and it will point to a specialist where a matter is beyond a visual look.

A report that recommends "further investigation by a specialist" isn't a weak report — it's an honest one. It's a recommendation to get a specialist assessment (a registered electrician, a weathertightness or structural specialist, an asbestos or methamphetamine tester), not a finding that a defect does or doesn't exist. The alternative — inventing a conclusion the inspection couldn't support — is exactly what gets inspectors into trouble.

For the same reason, a proper report is clear about what it excludes: a building-code compliance assessment, structural or geotechnical engineering, a weathertightness guarantee, specialist testing of electrical/gas/plumbing services, hazardous-materials testing (asbestos, methamphetamine, lead), pest inspection, and valuation. Each needs a separately engaged specialist.

What separates a defensible report from a weak one

If a report is ever questioned, a few things decide whether it holds up:

A clearly stated scope — what was and wasn't inspected, recorded specifically, not behind a generic disclaimer.
Evidence attached to each finding — photos, ideally with time and location, so a defect traces back to what the inspector actually saw.
Honest limitations and referrals — flagging rather than guessing.
A version that can't be quietly edited after it's issued, so the client's copy is the record.

Writing NZS 4306 reports?

HammerHand captures an NZS 4306 walkthrough by voice and photo, keeps "specialist referral" as a valid outcome, embeds your scope and limitations in the document itself, and locks the finished report as an immutable, dated snapshot with provenance — so it holds up. Offline on site, drafted for you, verified by you.

See the NZS 4306 tool Register your interest

Frequently asked questions

What is NZS 4306?

The New Zealand Standard for residential property inspections. When a buyer asks for a pre-purchase building report, this is the standard a proper one is written to — it sets out what the inspector examines and how the report is structured.

What does an NZS 4306 report cover?

The building systematically — site and grounds, exterior, roof and roof space, subfloor, interior and wet areas, and the accessible services — with the condition of each and any defects, plus a clear statement of what couldn't be inspected and why.

Why does a report say "further investigation by a specialist"?

Because a visual inspection has limits. Where a matter is beyond a non-invasive look, the report recommends a specialist assessment — an honest outcome, and a recommendation to investigate, not a finding that a defect does or doesn't exist.

What's excluded from a pre-purchase inspection?

Typically: code-compliance assessment, structural/geotechnical engineering, weathertightness guarantees, specialist testing of services, hazardous-materials testing (asbestos, methamphetamine, lead), pest inspection and valuation — each requiring a separate specialist.

What makes a report defensible?

A clearly stated scope, evidence attached to each finding, honest limitations and referrals, and a published version that can't be quietly edited after the fact.

This guide explains NZS 4306 in plain English for buyers and inspectors; it isn't legal advice and doesn't replace the standard itself or an inspector's professional judgement. Last checked August 2026.