Using your home equity to buy an investment property is how most Australian investors get started. Not by saving a second deposit from scratch. By putting the equity they have already built to work.
If you own a home that has risen in value, you may be closer to your first investment property than you think. Here is how home equity actually works, how it reaches the deposit, and the two structuring mistakes that quietly cost investors thousands.
What usable equity actually means
There are two numbers here, and only one of them counts.
Your total equity is your home’s value minus what you owe. If your home is worth $800,000 and you owe $440,000, your total equity is $360,000.
Your usable equity is smaller. Lenders will generally let you borrow up to 80% of your home’s value before they charge Lenders Mortgage Insurance (LMI). So the sum is 80% of the value, minus your loan:
- 80% of $800,000 = $640,000
- Minus the $440,000 you owe = $200,000 usable
That $200,000 is what you have to work with. Not the $360,000. The gap sits above the 80% line, where LMI kicks in and lenders turn cautious, because property values can move 10-15% in a single cycle.
How the equity reaches the deposit
Equity is not cash. You cannot spend it until you convert it into a loan. There are a few ways to do that:
- Top-up: your existing lender lifts your home loan limit up to the 80% mark and releases the funds.
- Separate equity loan (a split): a standalone loan account secured against your home, kept apart from your existing mortgage. This is usually the better structure, for reasons below.
- Refinance: move to a new lender and release the equity as part of the switch.
However you do it, the released funds become your deposit and buying costs on the investment property. A $200,000 release covers a 20% deposit plus stamp duty and legals on an affordable investment property. On a $600,000 purchase, that is roughly a $120,000 deposit and $25,000 to $35,000 in costs depending on the state, with a buffer left over. Our property purchase cost calculator breaks those upfront costs down state by state.
One catch worth knowing: the lender’s valuation, not your estimate, sets the number. Banks tend to value conservatively, and a valuation that comes in low shrinks your usable equity on the spot. It is worth ordering an upfront or desktop valuation through your broker before you build a plan around a figure, because the gap between what you think your home is worth and what the bank will lend against can be $50,000 or more.
Keep your interest deductible
Here is the mistake that quietly costs people the most.
The ATO decides whether your loan interest is tax deductible based on what you use the borrowed money for. Not what the loan is secured against. Borrow against your home to buy an income-producing investment property, and the interest on that borrowing is generally deductible. The security being your own home does not change that.
Mix the purposes, though, and you create a mess. If you draw equity into your existing home loan account, then spend some on the investment deposit and some on a car or a holiday, you now have one loan doing two jobs. Every repayment has to be split between deductible and private debt for the life of the loan. Untangling it later is painful, and the ATO has flagged incorrect interest apportionment as a specific focus area.
Keep the investment borrowing in its own separate loan account. One purpose, one account, clean deductions. For the full list of what you can claim once the property is running, see our investment property tax deductions guide. And talk to your accountant before you draw a dollar.
Avoid cross-collateralisation
When you buy the investment property, the bank will often suggest securing the new loan against both properties, your home and the investment. This is cross-collateralisation, and for an investor building a portfolio it is usually the wrong move.
Tie both properties to both loans and you hand one lender control of everything. Sell the investment later and the bank can direct where the proceeds go, or force a revaluation of your home. Refinance one and both get revalued. One low valuation can block the whole move.
The alternative keeps them separate. Release the equity from your home as its own standalone loan under 80% LVR, then take a separate loan for the investment, often with a different lender. Same deposit, same purchase, no entanglement. Structured this way each loan sits at or under 80%, so you can also sidestep LMI. Investors have been caught paying $5,000 or more in unnecessary LMI premiums purely because their loans were cross-secured.
Can you actually service it?
Having the equity is only half the test. The bank still has to be satisfied you can repay the new debt, and the rules tightened in 2026.
Two things to know:
- The 3% buffer. Lenders must assess you at your actual loan rate plus 3%. With variable investor rates above 6%, you are being tested at around 9%. Your real borrowing power is smaller than today’s rate makes it look.
- The DTI cap. From February 2026, banks can write only 20% of new lending to borrowers whose debt is six times their income or more, and they count owner-occupier and investor loans separately. Releasing equity pushes your total debt up, so high-equity investors are exactly who this constrains. Loans for brand-new dwellings are exempt.
None of this stops you. It means the order of operations matters: get your borrowing capacity checked by a good mortgage broker before you go looking, not after you have found the property. Using interest-only lending on the investment debt is one lever that helps the numbers work while you hold.
Equity is the start, not the strategy
Equity gets you to the starting line. What you do with it decides the result.
The temptation is to buy something comfortable and close to home. The data rarely agrees. We buy in affordable markets across the country where the growth and yield numbers stack up, because the best opportunity at any moment is seldom in your own suburb. Equity from a Sydney or Melbourne home has funded first investments in cheaper, faster-moving markets many times over.
Used well, one property’s equity funds the next, and the one after that. That is how a single home becomes a portfolio. For the full sequence, see how to build a property portfolio from scratch. If you are still weighing up the basics, start with our property investment for beginners guide.
Sources
- How usable equity and the 80% LVR rule work - Hunter Galloway
- Home equity calculator - Westpac
- Interest deductibility depends on the use of funds, not the security - ATO TR 95/25
- APRA serviceability buffer (3%) and the debt-to-income limit from February 2026 - APRA
- Why investors avoid cross-collateralisation (and the 80/20 alternative) - Home Loan Experts
This is general information only and not financial, tax, or credit advice. Loan structuring and deductibility depend on your circumstances. Speak to a licensed mortgage broker and a qualified accountant before acting.
If you have equity in your home and want to know what it could buy across Australia’s best-performing markets, book a free discovery call.
