How to Use Your Home's Equity to Buy an Investment Property

The Idea in One Sentence

If you own a home and you've been paying it off for a few years, there's a fair chance you're sitting on wealth you've never put to work. Using your home's equity to buy an investment property is, at its core, one simple idea: the value you've already built in your home can fund the deposit on your next property - without you needing to save it from scratch.

As Adel Pearce writes in 'From Payslip to Property': "Working hard isn't the same as building wealth." Most families work hard, pay the mortgage, and let the equity sit there doing nothing. This guide walks through the whole mechanism, step by step, in plain English.

First: What Is Equity?

Equity is simply the difference between what your home is worth today and what you still owe the bank.

If your home is worth $800,000 and your mortgage balance is $400,000, you have $400,000 of equity. It grows in two ways: every repayment you make chips away at the loan, and every bit of growth in your home's value adds to the top. Both happen quietly in the background - which is why many homeowners have far more equity than they realise.

But here's the catch: you can't use all of it. That's where usable equity comes in - and it's worth understanding properly. We've written a full deep-dive on it: usable equity explained.

How Lenders Let You Borrow Against It

Lenders will generally let you borrow against your home up to around 80% of its value, keeping roughly a 20% buffer of equity in the property. That buffer protects both you and the lender if values move around.

So the rule of thumb looks like this:

Using the example above: 80% of $800,000 is $640,000. Take away the $400,000 you owe, and you have around $240,000 of usable equity. That's not cash in your pocket - it's borrowing capacity secured against your home, which a lender may let you access as a separate loan.

How much you can actually borrow also depends on your income, expenses and existing commitments - your equity sets one limit, and your serviceability sets another. Our guide on how much you can borrow covers that side of the equation.

Equity Becomes the Deposit - and the Costs

Here's the part that surprises people: when you buy an investment property this way, the deposit doesn't have to come from savings. The equity you release from your home covers it - typically a 20% deposit on the new property, plus purchase costs like stamp duty, legal fees and inspections.

That's why "I don't have the deposit" is often the wrong conclusion. Plenty of families who feel like they could never save a six-figure deposit are already sitting on one. It's just wearing a disguise - it looks like the house they live in.

The Two-Loan Structure

A common way to set this up is with two separate loans, kept deliberately apart:

Keeping the two loans separate - rather than lumping everything into one big mortgage - keeps the structure clean. It's clear which borrowing relates to the investment, which your accountant will thank you for, and your home loan stays its own tidy thing. Interest on loans used for investment purposes is generally treated differently at tax time - that's one for your accountant, and a good reason the structure matters.

A Worked Illustration

Let's put round numbers on the whole journey, start to finish:

This is a general illustration only, not a forecast, quote or recommendation. The figures are rounded, hypothetical numbers used to show how the structure fits together. They are not a prediction of your position or your result, and they don't account for your income, lending criteria, interest rates, fees or tax. Property values can fall as well as rise. Seek independent professional advice before making any financial decisions.

In this illustration, a family with no spare cash savings ends up owning a $500,000 investment property - funded entirely by equity they'd already built. And notice what's left over: they used $125,000 of their $240,000 usable equity, leaving headroom for buffers.

What Do the Repayments Look Like?

This is the question that keeps people up at night, so let's be straight about it: yes, you're taking on more debt, and yes, there are repayments on both new loans. But you're not carrying them alone.

The rent from the investment property contributes to the repayments. A well-chosen property in an area with solid rental demand brings in income every week, and that income does a lot of the lifting. Depending on the property, the loans and your tax position, you typically cover the gap between the rent coming in and the costs going out - and for many investors that gap is a manageable weekly amount, not a second mortgage's worth of pain.

The size of that gap depends on the property, interest rates and your circumstances - which is exactly why the numbers get mapped out properly, in black and white, before you commit to anything. No surprises. If you're weighing this against simply paying your home loan down faster, our guide on investing versus paying off the mortgage walks through that trade-off honestly.

The Risks - Honestly

Borrowing to invest is a powerful tool, and like any powerful tool it deserves respect. Here's what to keep front of mind:

This is why buffers matter so much. Notice that the illustration above deliberately left usable equity on the table. Borrowing to your absolute limit is how people get into trouble; borrowing well inside it, with a buffer for the unexpected, is how people sleep at night. Strategy beats emotion - in both directions.

Where to Start

Everything in this guide flows from one number: your position. What your home is worth, what you owe, what your equity could support, and what fits your income and your goals. Until you know that, it's all theory.

The Delphi Scorecard is the place to start - it takes under 5 minutes and shows you where you stand. And if it makes sense, book a free chat and we'll walk through your numbers together, in plain English, with no pressure.

General information only. Not personal financial advice.