In this section
New Zealand Building Code: One National Rule Book
New Zealand runs a single national Building Code with Acceptable Solutions, so there are no regional variations to track — just the rules and the calculators that solve them.
Rules by topic
The parts of the code a chippie actually sets out — each one in plain English, with the numbers and a calculator.
Footings & slabs
Room heights
Wet areas
One code for the whole country
New Zealand has one Building Code, and it covers the whole country. There are no state, regional or council versions. Whether you build in Auckland, Christchurch or a small rural town, the same national rules apply. Every council checks your work against the same book.
The Building Code is run by MBIE (the Ministry of Business, Innovation and Employment). It sets out what a building has to do — stay standing, keep people safe, keep the weather out — but not always the exact numbers.
Where the numbers come from
Most of the numbers a chippy sets out on site come from an Acceptable Solution. That’s a recipe MBIE writes that is “deemed to comply” — if you build to it, the council accepts it without argument. For stairs that’s D1/AS1, and for barriers it’s F4/AS1.
The Acceptable Solution is the standard path, but it is not the only legal path. A designer can instead use a Verification Method (a test or calculation) or an Alternative Solution (a different design that still meets the Code). Those can carry different numbers. So treat the numbers on these pages as the normal, safe route — not the only one allowed.
One more thing: MBIE updates these documents. Always check the current amendment on building.govt.nz before you sign off on a job.