The Building Act 2004, in plain English

The Building Act 2004 is the master legislation — everything else in the system hangs off it. It matters to you because it decides when you need a consent, who’s allowed to do the structural and weathertightness work, and what you’re still on the hook for long after the job’s handed over.

The Code vs the Act: what’s the difference?

These two get muddled on site all the time, so it’s worth being clear. Think of it as a split:

• The Building Code (a regulation made under the Act) sets the WHAT — the performance every building has to achieve.
• The Building Act sets the HOW and WHO — when you need consent, who’s allowed to do the risky work (Restricted Building Work and LBPs), and the consumer-protection rules that follow you for years.

The Act was substantially rewritten after the leaky-homes crisis to put accountability back into the system.

The key sections a builder should know

You don’t need to be a lawyer, but a handful of sections come up on nearly every job:

• s14F — Building Code: all building work must comply with the Code.
• s40 — Restricted Building Work (RBW): structural and weathertightness work must be done or supervised by an LBP.
• s41–44 — Building consent: when it’s required, the exemptions, and the process.
• s362I–T (Part 4A) — consumer protection: implied warranties, the defect repair period, and maintenance disclosure.
• s393 + Limitation Act 2010: a 10-year longstop on building claims.

When work is exempt from consent

Not everything needs a consent. The Act carries schedules that spell out the exempt work:

• Schedule 1 — exempt work: minor work that doesn’t need consent. It lists 40+ categories.
• Schedule 1A (from 15 Jan 2026) — new: small standalone dwellings (granny flats) up to 60m² can be exempt under specific conditions.