The questions and original answers

For a renovation budget of around $60,000, the key is to show your lender three things: what the work will cost, how much you need to borrow, and how comfortably you can afford the higher repayments.

In New Zealand, increasing your existing mortgage to fund renovations is often called a mortgage top-up or loan increase. Your current lender is a sensible first place to ask, because they already know your loan history, although they'll still need to assess your finances and the property's value.

Here's what I'd have ready before contacting them.

1. Your renovation paperwork

Written quotes from your builders and tradespeople

Have the quotes for the $60,000 of work, ideally itemised by job, materials and labour. Check whether GST is included, how long the quotes are valid, and whether any work is excluded.

A clear scope of work

Write down what you're renovating, what the finished result will be, and the planned start and completion dates. If the project involves structural changes, additions or other work requiring council approval, include any relevant consent documents or plans.

Your total project budget

Include the quotes, any design or consent fees, and a contingency for unexpected costs. For example, a 10% contingency on $60,000 is $6,000, making a planning budget of $66,000. This is a buffer to consider, not necessarily an amount you need to borrow.

If you have more than one quote for the same work, you don't necessarily need to finalise every contractor before making an initial enquiry. A reasonably detailed estimate is a good starting point.

2. Your financial information

Your lender will want to understand your current position and whether the additional borrowing is affordable.

Gather these documents

Recent payslips for each borrower

Employment details, or business accounts and tax returns if self-employed

Recent bank statements, if requested

Current mortgage balance and repayment details

Details of other debts: credit cards, car loans, personal loans and buy-now-pay-later accounts

A realistic household budget covering food, utilities, childcare, transport, insurance and other expenses

Details of savings or cash you plan to contribute

0 of 7 items ready

The lender may have its own application checklist, so you don't necessarily need every document for the first conversation. They'll assess your income, existing commitments and living costs to decide what you can afford. Borrowing to renovateFind out how much of a mortgage you could get » Sorted

3. Know your mortgage and property position

Before the meeting, try to find out:

• Current mortgage balance: How much you owe now, including any separate loan splits.
• Estimated home value: A recent valuation, council rating valuation or a realistic market estimate. The bank may require a registered valuation, particularly if the amount borrowed relative to the property's value is high.
• Available equity: Broadly, this is your home's value minus the mortgage secured against it. Having equity helps, but it doesn't guarantee approval.
• Current loan structure: Your interest rate, fixed-rate expiry dates, remaining term and repayment frequency.

For example, if your home is worth $900,000 and your mortgage balance is $500,000, borrowing another $60,000 would bring the total loan to $560,000, or about 62.2% of the home's estimated value. That's a useful starting calculation, but the lender must confirm the valuation and its lending criteria.

4. Be ready to explain how you'll repay the extra $60,000

Ask the lender to show you the effect on your repayments, rather than focusing only on whether they'll approve the top-up.

As an illustration, here's what a separate $60,000 loan portion might cost if repaid with principal and interest over 20 years:

Illustrative interest rate	Approx. monthly repayment
5%	$396
6%	$430
7%	$465

These are examples, not current rate quotes. They exclude fees and assume the interest rate stays the same throughout the 20 years.

You can also experiment with the Sorted mortgage calculator. Mortgage calculator

One important consideration: putting renovation costs onto a mortgage can reduce the regular repayments, but if you take the full 20–30 years to repay that extra borrowing, the total interest can be substantial. Ask whether you can put the renovation amount into a separate loan split with a shorter repayment term, while leaving your existing mortgage arrangements intact.

5. Questions worth asking your lender

I'd take this short list to the conversation:

• Can we increase our existing mortgage by $60,000, or would you recommend a different structure?
• Will you require a registered valuation or evidence of the property's expected value after renovation?
• What documents, building quotes, consents or contracts do you need?
• What would our new repayments be at today's rates, and if rates rose by 1–2 percentage points?
• Can the extra borrowing have its own interest rate and repayment term?
• Would changing our existing fixed-rate mortgage trigger any break costs?
• Are there application, valuation or legal fees?
• Do we need to arrange additional insurance during the renovation?

If consent is required for your project, ask the lender when it needs to see the council consent and building contract. You should also check whether your home insurance covers the work or whether contract works insurance is needed. Borrowing to renovateHow to find a good deal on your mortgage » Sorted

My recommendation

Contact your existing lender before committing to the renovation contracts. Give them the quotes, an outline of your income and debts, your current mortgage balance and your best estimate of the home's value. Ask for an initial assessment of both borrowing capacity and likely repayments.

You don't need to have everything finalised to start that conversation.

One thing that would help me tailor the next step: roughly how much is your home worth, and how much is left on your mortgage? With those two figures, we can estimate what the equity position might look like if you borrow the additional $60,000.