A lot of Australian homeowners are sitting on more investment capital than they realise, and it's already in their property. If you bought a home two or more years ago and the value has grown, you may have built up enough equity to fund the deposit on an investment property without touching your savings at all. This isn't a complicated strategy reserved for experienced investors. It's a practical, well-established approach that KM Financial Service has helped hundreds of clients across Australia execute properly, structured and clearly understood, with the right lender behind it.
Home Equity vs Usable Equity: Understanding the Difference
Your home equity is the difference between what your property is worth today and what you still owe on your mortgage. If your home is worth $850,000 and your remaining loan is $480,000, your total equity is $370,000. But you can't access all of it.
Lenders typically allow borrowing up to 80% of your property's value without triggering Lender's Mortgage Insurance (LMI). Your usable equity is the portion of that 80% threshold remaining after subtracting your outstanding loan balance.
Usable Equity = (Property Value × 80%) − Outstanding Loan Balance
Example: $850,000 × 80% = $680,000 − $480,000 = $200,000 usable equity
That $200,000 is what a lender will let you access, and it's what can fund the deposit on your next property.
The Rule of Four: Estimating What You Can Buy
A simple way to estimate your investment property purchase price is the Rule of Four: multiply your usable equity by four. This works because lenders typically provide 80% of the investment property's value as a loan, with your equity covering the remaining 20% deposit.
Using the example above, $200,000 usable equity could support a purchase of around $800,000. The lender funds $640,000 (80%), and your equity covers the $160,000 deposit.
This is a rough estimate only; your actual borrowing power will depend on your income, existing debts, and lender assessment.
How the Process Works Step by Step
Accessing equity to buy an investment property involves two separate transactions, not one. Understanding this upfront avoids confusion later:
• Step 1 - Get a current valuation: Your lender will order their own formal valuation of your existing property. This may differ from online estimates; lenders tend to be conservative. This is the number that determines your usable equity, so it's the starting point
• Step 2 - Apply to access the equity: This is done by either refinancing your existing loan or applying for a loan top-up. The released equity goes into a separate loan facility or offset account, ready to be used as a deposit
• Step 3 - Apply for the investment loan separately: The investment property loan is taken out as a separate loan, secured against the investment property, not cross-collateralised with your home. This is critical for protecting your long-term flexibility
• Step 4 - Settlement: Your equity funds the deposit. The investment loan funds the balance. You now hold two loans, two properties, and a portfolio that's beginning to work for you
Read More: Smart ways to unlock equity for your business goals
What Lenders Will Actually Assess Before Approving
Having enough usable equity doesn't automatically mean approval. Lenders run a separate serviceability assessment to check whether your income can comfortably service both your existing mortgage and the new investment loan. Lenders are required to assess repayments using a buffer of at least 3% above the actual interest rate. With investment loan rates generally in the mid-6% to low-7% range, that means your repayments are typically assessed closer to 9.5–10%, depending on the lender.
From February 2026, APRA also introduced a debt-to-income (DTI) cap limiting authorised deposit-taking institutions from writing more than 20% of new residential mortgage lending where the borrower’s DTI ratio is 6 or higher. If your combined debt after the investment purchase would put you above that threshold, some lenders may decline even with strong equity. A broker who understands which lenders have room in their DTI quotas is genuinely valuable at this stage; it's not just about who offers the best rate.
One Structure Mistake That Can Cost You Later
The most common structural error when using equity to buy an investment property is cross-collateralisation: letting one lender use both your home and your investment property as combined security for both loans. It feels simpler at the time, but it gives the lender significant control over your entire portfolio. If you want to sell one property, refinance one loan, or access equity later, the lender's consent and revaluation process applies to everything, not just the relevant property.
The better structure and the one that KM Financial Service consistently recommends is standalone loans for each property, held with separate security. It's no harder to set up from the start, and it protects your ability to make independent decisions about each asset as the portfolio evolves.
Frequently Asked Questions
FAQ: Do I need to save a separate cash deposit to buy an investment property using equity?
Answer: Not necessarily. If your usable equity is sufficient to cover the 20% deposit, keeping the investment loan's LVR at or below 80%, you can avoid a separate cash deposit and also avoid LMI. You will still need cash for stamp duty and acquisition costs, which typically run 4–5% of the purchase price and cannot be funded through equity in most cases.
FAQ: Can I use equity if I'm still paying off my first mortgage?
Answer: Yes, and most borrowers who use equity still have a mortgage outstanding. What matters is the usable equity available within the 80% LVR threshold, not whether the home is paid off. Serviceability, your income's ability to cover both loans at the buffer rate, is the key assessment, not the mortgage balance alone.
How KM Financial Service Helps You Use Equity the Right Way
Kris Menon and the team at KM Financial Service bring nearly two decades of experience working with buyers across Australia & have been helping borrowers for 20 years. The team specialises in structuring investment property loans, helping you assess your equity position, identify the right lender for your income and DTI profile, and structure the loans so your portfolio can grow, not stall at one property. No cross-collateralisation. No surprises. One clear plan.
Book a consultation with KM Financial Service, or call 0402 879 531. Whether you're ready to move or just exploring what's possible, Kris and the team will show you exactly where you stand.
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