The questions and original answers

Yes. In New Zealand, some banks are better suited than others to helping you pay off an extra $60,000 of mortgage borrowing faster. The key, though, isn't necessarily switching banks — it's finding a mortgage structure that lets you target the renovation debt separately, make extra repayments efficiently, and reduce the interest you pay without creating unnecessary fees or restrictions.

If your current bank hasn't helped you work through the options, I'd compare how a few other banks structure their home loans and how clearly they explain the trade-offs.

The three mortgage options worth looking at

1. A separate loan split

You keep your main mortgage as it is and put the $60,000 renovation portion into its own loan account. You can then choose a repayment plan specifically designed to clear that portion sooner.

Best for: knowing exactly how quickly you're paying off the renovation costs.

2. A floating or flexible loan

You put some or all of the renovation debt on a floating rate, which generally allows extra repayments at any time without fixed-rate break fees. The trade-off is that floating rates are often higher than fixed rates.

Best for: people who can consistently pay more than the minimum, or who receive irregular lump sums.

3. An offset or revolving-credit mortgage

Your savings, or cash held in an eligible linked account, can reduce the balance on which interest is charged. A revolving-credit facility can also provide flexibility to pay the balance down and redraw funds, subject to the facility's limits.

Best for: households with savings, a cash buffer, or enough income discipline to keep the balance trending down.

One important detail: if the $60,000 is currently bundled into a fixed-rate mortgage, you generally can't just start making unlimited extra repayments on that portion without checking your bank's rules. A separate loan split may make it easier to choose a suitable structure when the fixed term ends.

Which NZ banks would I compare first?

Based on the loan features they publicly offer, I'd start with these four. This is a comparison of their mortgage options, not a claim that one bank has universally better customer service.

1. Kiwibank

A good first comparison if you want a mortgage split between fixed and flexible borrowing. It offers fixed, variable, revolving-credit and offset loans, and explains how to combine them. Its fixed loans generally allow extra repayments up to 5% of the starting balance per year without a break cost, subject to terms. Structuring your home loan | Home loansFixed rate home loan | Home loans

See: Kiwibank loan structures

2. BNZ

Worth comparing if you have savings or want to direct surplus cash towards the renovation debt. Its TotalMoney offset mortgage links eligible transaction accounts to your loan, reducing the balance charged interest. It also offers floating and revolving-credit options. TotalMoney home loans - Offset mortgagesHome loan types

See: BNZ TotalMoney

3. Westpac

Particularly relevant if you want the main mortgage fixed while paying down a smaller floating portion as quickly as possible. Westpac explicitly describes splitting a home loan to combine fixed-rate certainty with the freedom to repay the floating portion without prepayment costs. Split home loan

See: Westpac split home loans

4. ANZ

Worth considering if you want structured guidance. ANZ offers Home Loan Coaches and explains fixed, floating and flexible loan options, including the limits on extra repayments during a fixed term. Getting your home loan structure rightSix ways to reduce mortgage interest costs

See: ANZ loan structuring

What I'd actually do with your $60,000

I'd ask each bank to model a separate $60,000 loan portion with a specific repayment target, while leaving the rest of your mortgage structured to suit your household.

For illustration, if the $60,000 were repaid as a separate principal-and-interest loan at an assumed 6% annual interest rate:

Repayment target	Approx. monthly repayment
3 years	$1,825
5 years	$1,160
7 years	$877

Illustrative estimates only, assuming a constant 6% rate and monthly repayments. Actual rates, fees and repayment requirements will differ.

The crucial question for the bank is: Can you put the renovation borrowing into its own account and make extra repayments against that portion without disturbing your main mortgage?

You may not need to change banks to do this. Your current bank might be able to restructure the borrowing, particularly when a fixed-rate period ends. If it cannot offer a suitable structure, comparing refinancing offers makes sense.

The questions I'd put to each bank

Ask them to answer these in writing, so you can compare like for like:

• Can you separate the $60,000 renovation borrowing from the rest of our mortgage?
• What would the interest rate and fees be if that portion were fixed, floating, offset or revolving credit?
• How much extra could we repay each year without incurring a break fee?
• Can you show us how long it would take to clear the $60,000 if we paid an extra $300, $500 or $1,000 a month?
• If we switched banks, what cashback, legal costs, discharge fees or fixed-rate break costs would apply?

You could also speak to a mortgage adviser who compares multiple lenders. Ask whether they can assess the whole mortgage structure, not just find you a lower headline interest rate.

Can I narrow this down for you?

There are two details that would make a real difference to which bank and loan type I'd favour.

1. Is your current mortgage fixed or floating? And, if fixed, when does the fixed term end?

2. How aggressively do you want to pay off the $60,000? For example, within 3 years, 5 years, or simply as fast as you comfortably can.

With those two answers, I can help narrow the options to the most suitable NZ banks and loan structures for your situation, rather than just giving you a generic list.