Written contracts, disclosure and warrantiesWhat the law gives you on every roofing job.

Where the $30,000 line sits

For residential building work, the Building Act sets a prescribed minimum price of $30,000 including GST. At or above that price, the contract must be in writing and dated.

A roofer who enters an unwritten contract at or above that price commits an infringement offence, with a fine of up to $2,000. Skipping the disclosure information or checklist carries the same maximum.

Below the line, a written contract isn't compulsory, but it's still the simplest way to avoid an argument. The official checklist even points out that the contractor may not be a builder at all. It covers any tradesperson doing building work for you directly, roofers included.

What's in the disclosure statement?

The disclosure statement tells you who you're really dealing with. It must show the contractor's full legal name and business type, a key contact person, and that person's LBP number if they have one.

It also lists every insurance policy for the work, with its amount of cover and exclusions, and any guarantees or warranties offered, with their period and limits.

The checklist that comes with it is general advice: ask for detailed quotes instead of estimates, compare like with like, and be careful about paying ahead of the work. Knowingly giving false or misleading disclosure information can bring a fine of up to $50,000 for an individual or $150,000 for a company.

If the contract leaves something out

If there's no written contract for work of $30,000 or more, the law deems a set of default clauses into the agreement. The same happens when a written contract misses required items such as who gets consents, how variations work, payment terms or how disputes are handled.

Under the defaults, the roofer gets all building consents before starting and gives you the code compliance certificate before the final payment claim. A change you ask for that affects the price or finish date has to be costed and timed in writing within 10 working days. Progress payments fall due 20 working days after a written demand. A dispute that isn't settled within 10 working days of written notice can go to mediation, with each side paying its own costs.

The warranties every roofing job comes with

Every residential building contract, written or spoken, includes warranties by law. The work must be done properly and competently, follow the plans, specifications and any building consent, use suitable materials that are new unless the contract says otherwise, comply with the law, be done with reasonable care and skill, and be finished by the agreed date or within a reasonable time.

If you told the roofer what the work is for, or the result you want, there's also a warranty that the work and products will be reasonably fit for that purpose.

These warranties apply even if the contract says something different. A clause that tries to stop you suing over them has no effect, except for a breach you knew about, or should reasonably have known about, when you signed. A later owner of the house can rely on them too.

They sit alongside the Consumer Guarantees Act, which requires services to be carried out with reasonable care and skill, and the Fair Trading Act. The Building Act's protections don't reduce your rights under either.

How does the 12-month defect period work?

You can give the roofer notice of a defect within 12 months of completion. They must fix it within a reasonable time of written notice, and the defect is presumed to be their responsibility unless they prove otherwise.

There are limits. A contractor isn't liable for a defect caused by something outside human control, by someone else's actions (including accidental damage), by failure to do normal maintenance, or by not getting repairs done as soon as practicable after the defect appeared. It's up to them to prove that cause.

The 12 months doesn't shorten your wider rights under the warranties. If a breach can be fixed and the roofer refuses or fails to fix it within a reasonable time, you can have someone else do it and recover the reasonable cost, or cancel the contract.

What you should get when the job is finished

As soon as practicable after finishing, the roofer must give you written completion information. It includes copies of their current insurance policies for the work, any guarantees or warranties on the materials or services (including whether they transfer and how to claim), and the maintenance needed to meet Building Code durability or keep a warranty valid.

Read the maintenance part closely. Metal roofing, for example, needs a small amount of ongoing maintenance to meet its durability requirements and keep its warranty. Skipping it can also hand the roofer a defence under the defect rules.

Failing to provide the completion information is an infringement offence, with a fine of up to $2,000.

How long do you have to act?

Under the Limitation Act 2010, a money claim is generally time-barred 6 years after the act or omission it's based on. If you only found out later, it's 3 years after you knew or should have known, with an outer limit of 15 years.

For building work, the Building Act adds a firm 10-year limit: no relief can be granted for a claim brought 10 years or more after the act or omission it's based on.

A change is coming but isn't law yet. The Building Amendment Bill, introduced on 29 June 2026, would require home warranties for consented residential work of $100,000 or more that includes restricted building work, if it's passed.