How to track renovation costs in New Zealand (and why the receipts matter)
Keep every quote, contract, invoice and receipt, and keep them together. A renovation's paperwork does more work after the job than during it: it is what backs a claim against your builder, an insurance claim, and any tax question when the property is sold.
Why renovation receipts matter in New Zealand
Your builder's warranties
Residential building work comes with implied warranties under the Building Act. They apply for up to 10 years, whether or not you have a written contract and whatever the contract says, and cover almost every aspect of the work: compliance with the Building Code, good workmanship, and finishing on time.
There is also a 12-month defect repair period. If defects appear within 12 months of the work being completed, your builder has to fix them.
Both are easier to use with the paperwork: the contract, the invoices showing what was done and when, and the date the work was finished.
Written contracts over $30,000
Residential building work costing $30,000 or more, including GST must have a written contract, and implied contract terms apply to it whether or not they are written down. Keep the signed contract with the invoices.
Tradespeople and suppliers
Services from a business are covered by the Consumer Guarantees Act: they must be carried out with reasonable care and skill and be fit for the purpose you asked for. Materials and appliances bought for the renovation carry the Act's guarantees too, which is one more reason to keep the receipt for the new oven beside the builder's invoice.
What to keep
| Record | Why |
|---|---|
| Quotes and the signed contract | What was agreed, and the implied terms over $30,000 |
| Builder and trade invoices | What was done, when and by whom, for warranty and defect claims |
| Receipts for materials and fixtures | Cost, supplier, and Consumer Guarantees Act claims |
| Receipts for appliances and chattels | Warranties, and depreciation if the property is a rental |
| Building consent and code compliance documents | Proof the work was signed off |
| Photos before, during and after | Evidence of condition, and what is behind the walls |
| Payment records | A bank statement line for every invoice |
A system that holds up
- One home for the project. A folder, a spreadsheet, or a project in an app. Every document for the renovation goes there, not into the general pile.
- Capture on the day. Photograph each receipt at the counter and save each emailed invoice as it arrives. Receipts from the hardware store are thermal paper and fade quickly.
- Note what each cost was for. "Bathroom: tiles" beats a bare total when you are working out a warranty claim three years later.
- Track against the budget. A running total stops the renovation's true cost being a surprise at the end.
- Keep a copy in New Zealand. If your records live in an overseas-hosted app, export them to your own computer once the job is done.
How long to keep it
For a home you own, keep renovation records for as long as you own the property, and longer if a sale is taxable: the costs are part of the calculation. The implied warranties run for up to ten years, so a job's paperwork needs to outlast them. For a rental, the income tax records for each year also have to be kept for seven years.
Sources
Common questions
How long do implied warranties last on residential building work in NZ?
Up to 10 years. The implied warranties in the Building Act apply to residential building work whether or not you have a written contract, and cover things like Building Code compliance, good workmanship and completing the work on time.
What is the 12-month defect repair period?
If defects in residential building work appear within 12 months of the work being completed, the builder has to fix them. It runs alongside the implied warranties.
Do I need a written contract for a renovation?
Yes, for residential building work costing $30,000 or more including GST. Implied contract terms apply to that work whether or not they are written down.
Can I claim renovation costs on my own home?
Not against your income: your own home is private. The costs still matter if the property is ever sold in a way that is taxable, or if part of it is used to earn income, so keep the receipts.
Keep reading
Rental property records for Inland Revenue: what landlords need to keep
What NZ landlords must keep for the IR3R, how repairs differ from improvements, and the interest, ring-fencing and bright-line rules the records support.
ReadHow long does a warranty last in New Zealand?
Under the Consumer Guarantees Act, for 'a reasonable time', which can outlast the manufacturer's warranty. How it works, and whether extended warranties pay.
ReadHow long do you need to keep receipts for Inland Revenue?
Seven years after the end of the tax year they relate to. What counts as a business record, when the clock starts, and where the records must be kept.
Read