ChatGPT · National
We're separating and own a mortgaged home. How do I compare keeping the house and taking on the loan with selling it, without overlooking the ongoing costs?
When you're separating and own a home with a mortgage, the biggest mistake is comparing the cost of keeping the house with the cash you'd receive from selling it, rather than comparing the full financial picture of both options over time.
In New Zealand, it's worth looking at three things separately:
- Affordability: Can you comfortably afford the home on one income, including all the costs beyond the mortgage?
- Fairness: How will you divide the home's equity and other shared assets and debts?
- Financial resilience: After making the decision, will you still have enough money for emergencies, retirement savings and unexpected house repairs?
The best option isn't necessarily the one that leaves you with the most equity. It's the one that gives you a sustainable budget and a fair financial outcome without leaving you too exposed.
1. Start with what the house is actually worth to you
Calculate your current equity before comparing the two options.
| Item | Example |
|---|---|
| Estimated home value | $850,000 |
| Mortgage balance | −$500,000 |
| Gross equity | $350,000 |
| Estimated selling costs | −$25,000 |
| Estimated net proceeds if sold | $325,000 |
These are illustrative figures, not estimates of your home or actual selling costs.
If you sell, the net proceeds may be divided between you according to your separation agreement and applicable relationship-property rules. If one person keeps the home, they may need to refinance the mortgage and compensate the other person for their share of the equity.
Important: Don't assume that taking over the mortgage automatically means you can afford it or that the bank will approve the change. The lender will need to assess the proposed borrowing and ownership arrangements.
2. Compare the full ongoing cost of keeping the home
The mortgage repayment is only one part of the budget. Build a monthly budget using actual bills, not estimates where you can avoid them.
| Ongoing cost | What to include |
|---|---|
| Mortgage | Principal and interest, or interest-only if applicable; test the cost when the fixed rate expires |
| Council rates | Annual rates divided by 12, allowing for likely increases |
| Home insurance | Building insurance and any excess you would need to cover after a claim |
| Contents insurance | Your own cover after separating |
| Repairs and maintenance | Roof, plumbing, appliances, painting, gutters and general wear and tear |
| Utilities | Power, internet, water and rubbish charges where applicable |
| Body corporate or shared-property costs | Levies, insurance contributions and special levies, if relevant |
| Transport | Changes to commuting, school runs or other travel costs |
| Other household expenses | Food, childcare, healthcare, debt repayments and personal expenses |
For repairs, don't budget only for the small jobs you expect this year. Consider the age and condition of the property and any large items likely to need replacing. A separate maintenance savings account can help prevent an unexpected repair from turning into new debt.
Also allow for one-off separation and ownership costs, such as legal advice, a valuation, mortgage restructuring, refinancing fees, moving expenses and any repairs needed before a sale.
3. Compare keeping versus selling side by side
Option A: Keep the house
Calculate the monthly cost and the cash left after settling the separation.
- Take-home income after separation
- Less all mortgage and home-running costs
- Less other living costs and debts
- Less regular savings for repairs and emergencies
- Less any new borrowing needed to buy out your former partner
Key question: Is the remaining money enough to live comfortably, not merely enough to meet the bills?
Option B: Sell the house
Calculate both the cash you receive and your new monthly budget.
- Expected sale price
- Less mortgage payout and selling costs
- Less any other agreed settlement payments
- Plus your share of the remaining proceeds
- Less moving costs, rental bond and relocation costs, if applicable
- Compare the new rent or alternative housing cost with your former home budget
Key question: Will the money released give you greater security, and can you afford suitable housing afterwards?
One important detail: if you keep the house, don't count all its equity as available spending money. Equity is tied up in the property unless you sell or borrow against it. You could be asset-rich but short of cash every month.
Likewise, if you sell, don't compare your former mortgage payment with rent alone. Include the cost of utilities, insurance, transport, savings and any change in housing needs.
4. Test whether keeping it is sustainable
Run three scenarios rather than relying on one optimistic forecast.
- Base case: Your expected income, current mortgage repayment and realistic household expenses.
- Stress case: A higher mortgage repayment when your fixed rate expires, a significant repair and a period of reduced income.
- Longer-term case: What your finances look like in two to five years, including likely maintenance, changes in family needs and your ability to rebuild savings.
If the house is affordable only when everything goes right, selling may provide more financial security. If you can afford it with a sensible buffer, keeping it may be worthwhile for stability, family reasons or a long-term housing plan.
A useful test is whether you can meet your normal costs, set aside money for maintenance and emergencies, and still save something for your future.
5. Don't overlook the equity buyout
This is often the deciding factor.
Suppose your home has $350,000 in gross equity. If you agree that your former partner receives $175,000, you may need to find that money while also taking responsibility for the mortgage.
Depending on the agreement and lending approval, that could mean:
- Increasing or restructuring the mortgage.
- Using savings to fund some of the buyout.
- Negotiating an alternative division of assets and debts.
- Selling the property if the buyout is not affordable or feasible.
A larger mortgage can make an otherwise manageable house unaffordable. Calculate the repayments on the new loan after the buyout, not just the current mortgage.
In New Zealand, the family home is generally covered by relationship-property rules, but the appropriate division depends on your circumstances and any valid agreement. You should each obtain independent legal advice before finalising a property-sharing agreement. See the Ministry of Justice guide to dividing relationship property. Divide relationship propertyUnderstand relationship property
6. Build your own comparison
You can use this simple worksheet to work out the numbers that matter most.
The worksheet deliberately excludes some important variables, including the actual settlement allocation, one-off legal and refinancing costs, the cash you'll retain after a buyout, and any emergency fund. Add these before making a final decision.
7. A practical order of operations
- Get a realistic market valuation and a current mortgage payout figure.
- Ask your lender to assess whether you can service the proposed mortgage alone, including the buyout if applicable.
- Obtain a written estimate of selling costs and compare it with the costs of refinancing and transferring ownership.
- Make a complete post-separation budget for both options, including maintenance and savings.
- Get independent legal advice before signing the property settlement, and confirm the lender's requirements before changing ownership or loan arrangements.
You can find further guidance through the New Zealand Government's separation information and the Ministry of Justice's relationship-property guidance. Separating from your spouse or partnerUnderstand relationship property
My main recommendation: Don't decide based on whether you can make the mortgage payment today. Decide based on whether you can afford the whole house, compensate your former partner fairly, and still have enough cash and flexibility to manage life on your own.
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Captured 11 October 2026