Renovating a property is one of the most common reasons NZ homeowners access additional mortgage finance. Whether you’re adding a bedroom, upgrading the kitchen, or doing a full gut renovation, there are several ways to fund it — and the right approach depends on the scale of work, your current equity, and how your lender assesses the project.
For large renovations ($50,000+), a mortgage top-up or construction facility is usually the cheapest option — mortgage rates are far lower than personal loan rates. You need sufficient equity in your home (typically total debt must not exceed 80% LVR after the renovation). Smaller renovations ($10,000–$30,000) are often funded with a personal loan to avoid the legal and valuation costs of mortgage restructuring. Always get a fixed-price contract from a licensed builder before approaching the bank.
Renovation Finance Options
1. Mortgage top-up (most common for large renos)
If you have equity in your home, you can apply to increase your mortgage by the renovation amount. The bank will assess your income and the post-renovation property value. Advantages: mortgage rates (typically 5–7%), tax-deductible if investment property. Disadvantages: legal fees, valuation required, bank approval needed, secured against your home.
Typical requirement: Total debt after top-up must not exceed 80% LVR (i.e. you need at least 20% equity after borrowing the renovation amount).
2. Construction facility
For major structural renovations (extensions, new rooms, significant structural work), the bank may require a construction facility rather than a simple top-up. Funds are drawn in stages as work progresses, with the bank or their valuer confirming completion at each stage. More structured but appropriate for large, staged projects.
3. Personal loan
For renovations under $30,000 or where you don’t have sufficient equity, an unsecured personal loan is an alternative. Rates are significantly higher (10–22% p.a.) but there are no legal fees, no valuation required, and approval is faster. Total cost is often comparable for small amounts over short terms.
4. Revolving credit / offset facility
If you have a revolving credit mortgage, you may already have access to funds up to your facility limit without needing additional approval. Useful for renovation costs paid progressively over time.
5. Credit card (small cosmetic renos)
For cosmetic improvements (paint, flooring, appliances) under $10,000, a 0% interest credit card or interest-free finance deal may be suitable — if you can repay within the interest-free period.
What Banks Look at for Renovation Lending
| Factor | Bank’s assessment |
|---|---|
| Current LVR | Must be under 80% after the renovation loan |
| Post-renovation valuation | Bank orders a “subject to renovation” registered valuation |
| Fixed-price contract | Required for construction facilities and large top-ups |
| Licensed builder | Most banks require LBP certification for structural work |
| Building consent | Required for structural, plumbing, electrical work — bank will ask |
| Income servicing | Your income must support the higher repayments |
Do Renovations Add Value?
Not all renovations return their cost in added property value. NZ evidence suggests:
| Renovation type | Typical value return |
|---|---|
| Kitchen replacement | 50–80% of cost |
| Bathroom addition | 60–90% of cost |
| Extension (additional bedroom) | 60–100% of cost |
| Outdoor deck / landscaping | 30–60% of cost |
| New roof / re-cladding | 30–60% of cost (but reduces buyer risk) |
| Cosmetic refresh (paint, carpet) | 100–150% in some markets |
| Swimming pool | Often less than cost in NZ climate |
Renovations in a strong market return more; in a flat or declining market, the same money may not be recouped. If you’re renovating to sell, focus on what buyers value most: kitchens, bathrooms, and condition.
Building Consent — When You Need It
Building consent is required for structural, plumbing, and electrical work under the Building Act. Without consent:
- Work is unlawful and must be remediated
- Insurance may not cover incidents arising from unconsented work
- The property may be harder to sell (disclosure obligations)
- Your bank’s mortgage over the property may be compromised
Consent required for: Extensions, new rooms, deck over 1.5m from ground, relocating plumbing, electrical panel upgrades, structural changes. Consent generally not required for: Like-for-like replacement of fixtures, painting, flooring, minor cosmetic work.
When in doubt, ask your local council.
Frequently Asked Questions
How much equity do I need for a renovation loan?
Most banks require total debt (including the renovation amount) to not exceed 80% of the post-renovation property value. If your home is worth $700,000 and you owe $400,000, you have $160,000 of accessible equity (80% of $700,000 = $560,000 minus $400,000). However, the bank will order a valuation confirming the post-renovation value.
How long does it take to get a renovation top-up approved?
For a standard mortgage top-up, 2–4 weeks for a bank decision (including valuation). A full construction facility may take 4–6 weeks. Using a mortgage broker can speed this up, as they know which lenders process renovation lending fastest.
Can I do the renovation work myself?
For cosmetic work (painting, tiling, landscaping), yes. For structural, plumbing, and electrical work, you must use licensed tradespeople for consent purposes. Banks generally require an LBP-contracted builder for any construction facility, even if you’re doing some work yourself.
What happens if the renovation costs more than budgeted?
If you’ve used a fixed-price contract, cost overruns are the builder’s responsibility (subject to agreed variations). Without a fixed-price contract, you’ll need to fund the shortfall — either from savings, additional borrowing (if equity allows), or by descoping the work. Never start a renovation without a realistic contingency budget of 10–15%.
Is renovation lending harder than standard mortgage lending?
It can be — banks are cautious about renovation risk. A straightforward top-up with sufficient equity is usually straightforward. A construction facility with staged drawdowns requires more documentation and active management. Use a mortgage broker if you’re unsure which structure to use.