# Building inspections before you buy > A pre-purchase building inspection checks for problems in a house before you buy. Find out what gets inspected, what could be missed and how to use the report. By Jason Dark, last checked 2026-11-05. Part of [Buying](https://buyingahouse.co.nz/buying) on Nester. ## The short version - Most inspectors follow NZS 4306:2005, so they check the site, structure, roof, cladding, interior and services. - A building inspection is a visual check done in one day, so it can miss serious problems and is no guarantee the house is sound. - A long dry summer can hide leaks and dampness. Be cautious about trusting good moisture readings if it hasn't rained in a while. - Ask a builder you trust to look at the house as well. They often spot things inspectors miss. - Pre-purchase inspectors don't need a licence. Check their experience and insurance before you book. ## What the inspection covers A pre-purchase inspection is a visual check of the house by someone who knows where problems can hide. In New Zealand, most inspectors use NZS 4306:2005, which explains what they check and what should be in the report. Under the standard, the inspector checks: - the site and drainage - the foundations and subfloor - the roof, the roof space and the cladding - the interior, including the bathroom, kitchen and laundry - decks and balconies - the plumbing, wiring and other services they can see Inspectors look for signs of dampness, rot, borer and movement, and anything else that might need a specialist to check. ## What it can miss The inspection is non-invasive. Inspectors don't lift carpets, remove wall linings or cut into cladding. They only check areas they can reach safely. The report is just a snapshot of the house on one day, and what it finds depends on the inspector and how thorough they are. The time of year matters too. If you buy at the end of February after a four-month drought, the ground will be bone dry and the house won't have seen rain for months. Moisture readings will look good, so you'll see the house at its best. To see it at its worst, visit in the middle of winter after weeks of bad weather. Some houses need more than a visual check. If the house has plaster or another monolithic cladding and was built in the late 1990s or early 2000s, the inspector might suggest invasive moisture testing. This means drilling small holes to take readings, and you'll need the vendor's permission. Meth testing is separate, so ask for it if you want it. ## What my inspections missed Two different building inspectors missed major problems on houses I was looking at. When I bought one house, the report didn't mention a leaking skylight that had rotted the framing around it. The report also missed that the seals on most of the north and west facing joinery had perished, which meant the windows and doors leaked. The most expensive problem the report missed was the home automation system, which controlled the lights and many other things, and was failing. The system was obsolete and very costly to replace. The wall switches ran on extra low voltage wiring with no 230-volt cables to them, so changing to standard switches would have meant running new cables, which would have been expensive too. These were just some of the problems with the house, and none of them were in the report. On another house, a different inspector found some rotting floorboards. My builder mate came by later and noticed something the report didn't mention. Part of the foundations had failed, so new foundations had been poured and steel I-beams added to spread the load. Structural work like this needs a building consent, so the council should have had a record, but it didn't. That, along with a few other things my mate found, is why I pulled out. Experience is the thing you get just after you needed it. Now I look closely at things I wouldn't have thought to check before. ## Get someone you trust to look too A building report will usually find the obvious problems. But less obvious issues can be missed, depending on who does the inspection and how thorough they are. There's a risk the report is just a box-ticking exercise that makes you and the bank feel better but doesn't really help, so if possible, don't rely on it alone for peace of mind. If at all possible, I suggest asking someone you know and trust to check the house carefully. This could be a builder, a family member who works in the trade or anyone who understands construction and knows what to look for. ## Choosing an inspector If you're hiring an inspector, remember that pre-purchase inspectors in New Zealand don't need a licence. Ask a few questions before you book: - Does your report follow NZS 4306:2005? - How much experience do you have with houses of this age and type? - Are you a member of a professional group such as BOINZ, NZIBS or NZIBI? - Can you show me proof of professional indemnity insurance? - How soon will I get the report? Hire your own inspector. A report from the vendor can help, but remember the inspector was working for them. ## Reading the report A good report includes photos, a summary of defects and a list of maintenance jobs. Separate the big problems, like a leaking roof, rot in the framing or a cracked foundation, from regular upkeep like repainting or fixing a dripping tap. Get a builder's quote for any expensive repairs before your condition date. A quote helps you negotiate. You can ask the vendor to fix the problem or lower the price. If your offer is conditional on a satisfactory building report, you can also walk away. ## Timing Make your offer conditional on a building report, and allow enough working days to book the inspection, get your builder in, read the report and get quotes. If you're buying at auction, you need to do the inspection before auction day. ## Sources - [building.govt.nz: Is a pre-purchase building inspection advisable?](https://www.building.govt.nz/getting-started/your-rights-and-obligations/homeowner-rights-and-obligations/buying-a-house/is-a-pre-purchase-building-inspection-advisable) - [building.govt.nz: What needs to be checked when buying a house](https://www.building.govt.nz/getting-started/your-rights-and-obligations/homeowner-rights-and-obligations/buying-a-house/what-needs-to-be-checked) - [Building Officials Institute of New Zealand (BOINZ)](https://www.boinz.org.nz/) - [New Zealand Institute of Building Surveyors (NZIBS)](https://buildingsurveyors.co.nz/) - [New Zealand Institute of Building Inspectors (NZIBI)](https://nzibi.co.nz/)