How to Structure Your Mortgage

What structure means

A home loan doesn't have to be one block. You can divide it into parts, each with its own rate type, fixed term and repayment. A structure is the pattern of those parts. A good one balances three things that pull against each other: certainty, cost and flexibility.

The building blocks

More detail in our guides to fixed versus floating and offset and revolving credit.

Why split fixed terms

Nobody reliably predicts interest rates. Economists don't, banks don't, and we don't. Splitting the loan across two or three fixed terms means you're never refixing the whole amount on one day at one rate. Part of the loan gets whatever comes next, good or bad.

It also staggers your options. With a tranche expiring each year, there's a regular chance to make a lump-sum repayment or change course without break fees.

It can be overdone. Five splits on a $400,000 loan is fiddly, and if you want to change lender, staggered expiries mean there's never a clean date to leave. Two or three parts is plenty for most households.

Questions that decide your structure

1. How tight is the budget? If a rise in repayments would hurt, lean towards longer fixed terms for certainty.
2. Do you expect lump sums? A bonus, a property sale, an inheritance. Keep an amount floating or on a short term to receive it.
3. Could you sell or move in the next few years? Avoid long fixed terms. Break fees on a sale are painful.
4. Is your income irregular? Self-employed and commission earners often do well with revolving credit to smooth the lumps.
5. Do you hold savings? An offset account puts them to work without locking them away.
6. Is a change coming? Parental leave, study, a new business. Build in flexibility before, not after.

Three example shapes

Illustrations only. They're not recommendations for you.

• First home, tight budget: most of the loan fixed across two terms for certainty, with a small floating part for extra repayments.
• Two incomes, paying down hard: a revolving credit or offset portion sized to what they can clear in a year, with the rest fixed and staggered.
• Home plus a rental: separate loans for each property so the interest is traceable for tax, rental debt possibly interest-only, and every spare dollar aimed at the home loan.

Review it, don't set and forget

The right structure for a couple with no children isn't the right one five years and two children later. Each fixed-rate expiry is a prompt to check. Our refix guide covers what to look at.

This article explains how New Zealand lenders generally assess these situations. It is general information, not personalised financial advice, and lender policy changes often — check your own position with a registered adviser. Official sources: Reserve Bank of New Zealand for lending policy and the OCR, and Sorted.org.nz for independent government-backed money guidance.