Top Strategies to Upsizing Your Home in Box Hill

When your second child arrives or your parents need to move in, you realise the two-bedroom apartment near the station won't work anymore.

You need another bedroom, maybe two, and suddenly you're looking at a loan that's $200,000 to $300,000 larger than what you currently owe. The question isn't whether you need more space. It's how to structure the new loan so you're not stretched too thin if circumstances shift.

How Much You Can Borrow When Upsizing

Your borrowing capacity depends on your household income, existing debts, and living expenses, with lenders typically capping repayments at around 30% of gross income. If you're a dual-income household earning $180,000 combined and own a property in Box Hill worth $950,000 with $400,000 still owing, your equity sits around $550,000. After selling costs of roughly 3%, you'd have approximately $520,000 to put toward a purchase in the $1.2 million to $1.4 million range, common for larger homes in streets near Whitehorse Road or closer to Box Hill Gardens.

Lenders will assess your borrowing capacity using current variable rate servicing buffers, usually adding 3% to the actual interest rate when calculating what you can afford. That means even if the rate you're quoted is 6.2%, the lender tests your repayments as though it were 9.2%. In our experience, medical professionals often have higher income but also carry HECS debt or professional indemnity insurance costs, which lenders factor into the assessment.

Using Equity Without Selling First

If you want to buy before you sell, you can access your existing equity through a bridging structure or by increasing your current loan to fund the deposit on the new property. A family living in a two-bedroom unit valued at $850,000 with a remaining loan of $350,000 could borrow against that equity to secure a deposit on a four-bedroom house, then repay the bridging portion once their unit settles. This approach works when you have at least 20% equity in your current property and can service both loans temporarily, usually for three to six months.

The alternative is a deposit bond, which some lenders accept in place of cash. You pay a small premium for a guarantee that covers the deposit until your existing property sells. Not every vendor will accept this, and it adds a layer of complexity to the contract, but it keeps your savings intact for settlement costs and avoids the pressure of a rushed sale.

Variable Rate, Fixed Rate, or Split for a Growing Family

A split loan lets you lock part of your borrowing at a fixed interest rate while keeping the rest on a variable rate with an offset account. Consider a radiologist purchasing a home in Box Hill for $1.3 million with a $900,000 loan. They fix $600,000 for three years at 5.9% to protect against rate rises during the years their children are in primary school, and leave $300,000 variable with an offset linked to their everyday account. Any surplus income sitting in that offset reduces the interest charged on the variable portion, which gives them flexibility if they want to make lump sum repayments or if one parent reduces their hours.

Fixed rates remove the uncertainty around repayments, but you lose access to offset features and you'll pay break costs if you need to sell or refinance early. Variable loans give you full access to redraw and offset, but your repayments move with the market. Splitting the difference is common when you want some certainty without giving up all your flexibility.

Principal and Interest Versus Interest Only

Principal and interest repayments build equity from day one, which improves your position if you want to borrow again or refinance down the line. On a $900,000 loan at 6.2% over 30 years, you'd pay around $5,500 per month and own roughly $60,000 more of the property after three years. Interest-only repayments on the same loan would be closer to $4,650 per month, but your loan balance stays at $900,000 unless you make voluntary payments.

Interest-only structures suit investors who want to maximise deductions and preserve cash flow, but for an owner-occupied purchase where you're planning to stay long-term, paying down the principal reduces your total interest cost and gives you a buffer if property values flatten. Some families use interest-only for the first year or two while they settle into higher childcare costs or one income, then switch to principal and interest once their budget stabilises.

Offset Accounts and Why They Matter More When Upsizing

An offset account linked to your home loan reduces the interest you're charged without locking funds into the loan itself. If you have $50,000 sitting in a linked offset and your loan balance is $900,000, you only pay interest on $850,000. That saves you roughly $3,000 per year at a 6% variable rate, and you can access the $50,000 whenever you need it for school fees, medical equipment, or an unexpected repair.

Not every loan product offers a full offset. Some lenders provide partial offsets that only reduce interest on a percentage of the balance, and others charge higher monthly fees for offset features. When you're upsizing and your loan amount is larger, the dollar value of the offset benefit increases, so it's worth comparing home loan features rather than focusing only on the advertised rate.

Getting Pre-Approval Before You Start Looking

Pre-approval tells you what you can borrow and gives you certainty when you're making an offer. It's particularly useful in Box Hill, where stock moves quickly around the schools near Mont Albert Road and Middleborough Road, and vendors often want short settlement periods. A conditional approval locks in your loan amount and interest rate for three to six months, so you're not scrambling to organise finance after signing a contract.

Lenders issue home loan pre-approval based on income verification, a credit check, and an assessment of your current debts. If you're self-employed or earning irregular income through locum work, you'll need to provide two years of tax returns and sometimes a letter from your accountant. Pre-approval isn't a guarantee, because the lender still needs to value the property and review the contract, but it removes most of the uncertainty before you commit.

What Settlement Costs Look Like on a Larger Purchase

When you're buying a home for $1.3 million in Box Hill, expect to pay stamp duty of around $70,000, plus legal fees of $1,500 to $2,500, building and pest inspections of $600 to $1,000, and lender establishment fees that vary by product. If your deposit is less than 20% of the purchase price, you'll also pay Lenders Mortgage Insurance, which can add $20,000 to $40,000 depending on your loan to value ratio.

These costs aren't part of your deposit. They're due at settlement, and they need to come from savings or equity released from your current property. Some buyers underestimate this and find themselves short a few weeks before settlement, which can delay the process or force them to borrow more than planned. Setting aside 5% of the purchase price for costs gives you a realistic buffer.

Call one of our team or book an appointment at a time that works for you. We'll review your equity position, compare home loan options from lenders across Australia, and structure a loan that fits your income and plans without locking you into features you don't need.

Frequently Asked Questions