Borrowing Strategy
Has the Downturn Shrunk Your Usable Equity? The Equity Math for Funding Your Next Land-and-Build
If you planned to fund your next investment from the equity in your home, the past seven months have changed the arithmetic. Cotality’s October Home Value Index (released 2 November 2026) shows national dwelling values down for a seventh straight month, while the RBA lifted the cash rate to 4.85% on 3 November. Lenders value your home today, not at the March peak, and every dollar of lost value cuts the equity you can use. This guide shows how to calculate usable equity properly, how to structure the release, and why a land-and-build purchase with a vetted independent builder is treated differently under the new debt-to-income rules.
The Problem: Your Equity Shrank Faster Than Your Loan
Your loan balance has not moved much since March. Your home’s value has. Cotality reports the national index is 6.7% below its March peak, roughly $63,400 off the median dwelling, and notes that Melbourne and Sydney owners are in a weaker equity position than owners in Brisbane, Perth and Adelaide after their larger upswings.
Lenders lend against current valuations, so every dollar of lost value removes 80 cents of usable equity at an 80% LVR limit.
ABS Lending Indicators for the September quarter (released 11 November 2026) show investor loan commitments fell 30.6% in number and 32.3% in value, while owner-occupier commitments fell 5.3%.
Fewer investors competing for land and builder slots is the opportunity, provided your funding still works.
Structure Options: Three Ways to Release Equity
Usable equity is not the gap between value and debt. It is the amount you can borrow against your home while staying at or below 80% loan-to-value ratio (LVR), which avoids lenders mortgage insurance at most lenders.
Separate equity split against your home. A new loan account secured by your home, used only for the deposit and costs of the investment. This keeps the purpose of the borrowing traceable, which matters for interest deductibility.
Cross-collateralisation. Both properties secure one combined facility. It looks simple but ties your home to the investment and makes future refinancing or sale harder. We generally steer investors away from it.
Higher LVR with mortgage insurance. Possible, but it raises total debt in a rising rate cycle and adds a cost that does not build any equity.
For most investors building a portfolio, option one is the cleanest structure.
Worked Example: An $850,000 Home and a $750,000 Land-and-Build
The figures below are illustrative assumptions, not a quote, except the Cotality index movement.
Home valued at $850,000 at the March peak, with $400,000 owing.
Usable equity at the peak: 80% of $850,000, less $400,000, equals $280,000.
Apply Cotality’s 6.7% national fall: the home is now valued at $793,050.
Usable equity today: 80% of $793,050, less $400,000, equals $234,440.
That is $45,560 of usable equity gone without a single repayment changing. Now apply it to a land-and-build purchase: $350,000 for titled land plus a $400,000 fixed-price build contract with a vetted independent builder, $750,000 in total.
Deposit at 20%: $150,000, plus an assumed $25,000 allowance for duty on the land contract and settlement costs. Equity required: $175,000.
Equity remaining after release: $59,440, which can be held as an undrawn buffer.
Investment loan at 80%: $600,000, drawn as the land settles and then in progress payments during the build, so interest accrues only on the amount drawn.
Total household debt: $400,000 + $175,000 + $600,000 = $1,175,000. On a gross household income of $200,000, that is a debt-to-income ratio of about 5.9 times.
Where the New Debt-to-Income Rules Favour New Builds
Since 1 February 2026, APRA has limited banks to writing no more than 20 per cent of new investment loans (and separately, owner-occupier loans) at a debt-to-income ratio of six times or more. In the example above, the investor sits just under that line. A modest change in income or price would push them over it.
APRA’s implementation details exempt finance for the construction of new dwellings and for the purchase of newly erected dwellings from the DTI limit.
An established purchase with the same debt does not receive that exemption.
The exemption applies to the construction finance; how a lender treats the equity split on your home is its own policy, so confirm it in writing before you sign a land contract.
APRA’s 3 percentage point serviceability buffer still applies to every loan, so passing the DTI test is not the same as passing serviceability.
Decision Framework: Should You Release Equity Now?
Run your own numbers through these four tests before committing.
If your usable equity at today’s valuation covers the 20% deposit, costs and a buffer of at least six months of loan repayments, the land-and-build structure is workable now.
If it covers the deposit but not the buffer, choose a smaller lot or lower build price rather than borrowing above 80% LVR.
If your DTI lands at or above six times, the new-build exemption becomes decisive; an established purchase is likely to face tighter lender appetite.
If your goal is to pay down debt faster or retire earlier, set a target date to repay the equity split from rental surplus, and track it separately from your home loan.
Verify the Structure With Your CPA Before You Draw
Tax and lending rules are complex and depend on your circumstances. Whether interest on an equity split is deductible depends on how the borrowed funds are used, and changes to negative gearing and capital gains tax settings from 1 July 2027 affect established and new property differently. Lenders also assess each application at your actual rate plus the 3 percentage point serviceability buffer, using their own expense and income shading.
Confirm deductibility and ownership structure with a Certified Practising Accountant (CPA).
Have a licensed mortgage broker or financial planner test serviceability with two lenders before you sign.
Order a desktop valuation of your home first; do not rely on the March figure.
What This Means for You: The downturn has reduced usable equity, but it has not closed the door. If a current valuation still leaves you at or below 80% LVR with a six-month buffer, a land-and-build purchase lets you build a portfolio and create passive income through a structure APRA’s DTI rules treat more favourably than established stock. Released through a separate split and repaid from rental surplus, that equity becomes the base for generational wealth rather than a drag on your home loan. If you are not sure yet where you stand, start with the valuation and the four tests above.
Next Step: Test Your Equity Before the Market Turns
Want to see how much of your equity is usable today and what it can fund? Book a Discovery Session and we’ll walk you through our usable equity and land-and-build funding framework, including the DTI and serviceability checks, then map it to your wealth goal.
Disclaimer: Legacy Property Investments provides property sourcing and strategic property analysis. Any information provided is of a general nature and does not constitute financial, legal, taxation, or investment advice. We strongly recommend seeking independent professional advice from a licensed financial adviser, accountant, and solicitor before making any property investment decision. Past performance is not a reliable indicator of future performance. Investing in property involves risk, including the potential loss of capital.