How to Use Equity in Your Home to Buy an Investment Property
A significant number of Australian homeowners who have been paying down their mortgage for five or more years, or who bought in a market that has moved, are sitting on a deposit for an investment property without realising it. The deposit is not in a savings account. For many homeowners, home loan equity can become the starting point for a future home equity investment property strategy.
Here is how that actually works, with the numbers shown at each step so the concept is concrete rather than theoretical.
The Numbers, From Start to Finish
Take a household in Sydney’s northwest who bought in 2020. The home was purchased for $780,000. After five years of P&I repayments and some market movement, the current lender valuation comes in at $920,000. The remaining loan balance is $540,000. Here is what that means in practice.
$380,000
Total equity: what this household actually owns
That is $920,000 minus $540,000. But this number is not the one that matters for investing; the lender doesn’t let you borrow against all of it.
$196,000
Usable equity investment loan potential: what they may be able to access
(80% of $920,000 = $736,000) minus $540,000 = $196,000. This is the deposit. Many lenders calculate usable equity around an 80% LVR position, although the exact limit depends on lender policy, valuation, borrower profile and serviceability.
$784,000
Maximum investment property purchase: the Rule of Four
$196,000 × 4. The rule works because lenders advance 80% of the investment property’s value, so equity covers the 20% deposit. In simple terms, this is how investment property deposit equity can replace the need to save a separate cash deposit.
In practice, that $784,000 ceiling will also need to account for stamp duty and costs, which for an investment property in NSW at this price sit around $30,000–$33,000. These costs usually need to be funded separately through equity or savings and should not be assumed as part of the main investment loan. A realistic purchase price with the full $196,000 in equity available sits closer to $720,000–$750,000 after costs.
Also Read: Real Cost of Buying a Home in Australia 2026: Stamp Duty, LMI & Hidden Costs
How the Loan Is Actually Structured
This is the part that genuinely matters for tax purposes and where the right equity loan structure Australia approach can make a major difference. A home loan for property investors should not only focus on rate; it should also protect deductibility, cash flow and future borrowing flexibility.
The first approach is a home loan top-up, adding the equity release to the existing home loan. Simple, and sometimes available same-day. The problem is that it mixes personal and investment borrowing in one account. If the same loan now funds both the home and the investment deposit, the interest cannot be cleanly split for tax purposes. The ATO requires that deductible interest be traced directly to income-producing use, and a blended loan makes that harder to demonstrate.
The second approach, which most brokers recommend, is a standalone equity loan, a separate loan split against the existing home, specifically to fund the investment deposit. Interest on that separate split may be deductible where the borrowed funds are used for an income-producing investment property, but the structure should be confirmed with a tax adviser. The existing home loan sits separately, unchanged. The investment property then takes its own new loan. Three separate facilities, with clean deductibility on two of them.
The tax outcome over ten years is materially different depending on which structure is used. The rate might look identical. The after-tax cost does not.
The Two Things People Underestimate
The first is serviceability. Having $196,000 in usable equity is not the same as having the income to service two loans. APRA confirmed in May 2026 that the mortgage serviceability buffer remains at 3 percentage points, which means the combined loan position must still work under a stressed assessment rate. A household that looks equity-rich on paper can still be declined if combined repayments on the home loan, the equity split, and the investment loan exceed what serviceability allows at the stressed rate.
The second is the lender’s valuation versus market estimates. The number a bank assigns to your property, which determines usable equity, is typically conservative, particularly in markets where automated valuations trail sales prices. A formal bank valuation is what matters for the equity calculation, not what similar homes are listed for or what a real estate agent suggests.
Where Safe Haven Finance Fits In
Payal Varma and the Safe Haven Finance team work through exactly this process with investors across Australia, mapping usable equity, modelling the right equity loan structure Australia approach, checking serviceability across different lenders, and identifying whether equity, cash or a combination is the better fit for the specific investment.
With access to more than 50 lenders and 20 years of experience as a mortgage broker Australia, the team compares options across the full market, not just one bank’s product shelf. Whether you need an investment property loan Australia structure, a separate equity split, or clarity on how much usable equity you can actually access, Safe Haven Finance helps you understand the numbers before you move.
Book a free strategy session at safehavenfinance.com.au or call +61 433 564 936. Follow Safe Haven Finance on Instagram, Facebook and LinkedIn.
Frequently Asked Questions
Q: Can I use equity to buy an investment property without any cash savings?
Answer: Potentially, if usable equity covers both the deposit and purchase costs like stamp duty. You still need to pass serviceability at APRA’s stressed assessment rate, and keeping a cash buffer for vacancies and repairs is strongly advisable.
Q: Why does it matter whether the equity is set up as a separate loan split?
Answer: Tax deductibility requires that interest be traced to its income-producing purpose. A separate equity split used solely for the investment deposit keeps the deduction clean; blending it into an existing home loan creates a mixed-purpose loan that complicates the tax position.
