Why Interest Rates Matter When You're Buying in Chadstone

Interest rates determine the size of the loan you qualify for before you see a single property.

A buyer looking at townhouses in Chadstone with a household income of $140,000 and a 15% deposit might find their borrowing capacity drops by around $50,000 to $60,000 if variable rates rise by just 0.5%. That figure compounds when you add the serviceability buffer lenders apply to every application. The result is that some buyers find themselves approved for less than the suburb median by the time their application is assessed, even though they could comfortably afford repayments at the actual rate they would pay.

How Lenders Calculate What You Can Borrow

Lenders assess your ability to service a loan by testing your income and expenses against a rate higher than the one you will actually pay. APRA requires lenders to apply a serviceability buffer of at least 3.0 percentage points above the loan product rate. If you are applying for a variable rate home loan currently sitting around 6.2%, the lender will assess your ability to repay at 9.2% or above. That buffer exists to ensure borrowers can still meet repayments if rates rise during the life of the loan.

The assessed rate, not the actual rate, determines your borrowing capacity. A buyer with $10,000 in monthly income and typical living expenses might be approved for a loan amount that results in repayments of around $4,500 per month at the assessed rate, even though the actual repayment at the product rate would be closer to $3,200. Lenders will not approve a loan amount that pushes the assessed repayment above the serviceability threshold, regardless of how comfortably you could manage the real repayment.

This is where rate movements have their most immediate effect. When the product rate rises, the assessed rate rises in lockstep, and your maximum loan amount contracts.

Why a Small Rate Change Affects Borrowing Capacity More Than Repayments

A 0.25% increase in the variable rate on a $700,000 loan adds around $120 to the monthly repayment. The same rate increase can reduce borrowing capacity by $20,000 to $30,000, depending on the lender's assessment method and your income level. The difference comes down to how lenders calculate risk over a 30-year term versus how borrowers experience cost over a single month.

Consider a buyer earning $150,000 per year with minimal other debts and a 10% deposit saved. At a variable rate of 6.0%, they might be assessed at 9.0% under the buffer and approved for a loan of around $750,000. If the rate rises to 6.5%, the assessed rate becomes 9.5%, and the same buyer's maximum borrowing capacity might drop to $720,000. That $30,000 reduction happens without any change to the buyer's income, deposit, or ability to meet the actual repayment. The lender is simply testing against a higher stress scenario.

For buyers in Chadstone, where the median unit price has been sitting in the mid-$600,000 range and townhouses often transact above $900,000, a $30,000 reduction in borrowing capacity can mean the difference between being able to make a competitive offer on a property near Chadstone Shopping Centre or needing to adjust expectations to smaller or less central options.

Fixed Rates and Borrowing Capacity

Fixed rate loans are assessed using the same 3.0 percentage point buffer, applied to the fixed rate rather than the variable rate. If a lender offers a three-year fixed rate at 5.8%, your borrowing capacity will be assessed at 8.8%. Because fixed rates are often lower than variable rates during certain rate cycles, fixing can sometimes improve your borrowing capacity at the time of application.

In our experience, buyers who lock in a fixed rate home loan during a period of rising variable rates can preserve a higher loan approval and secure properties they would otherwise be priced out of if assessed on a variable rate. Once the loan settles, the borrower benefits from the lower fixed rate repayments, even though the approval was based on the buffered rate.

One consideration is that fixed rates are not always lower than variable rates, and the assessment rate can still rise if the lender adjusts fixed rate pricing in response to wholesale funding costs. Fixing also removes access to offset accounts in most cases, which can affect cash flow for buyers with irregular income or those building up savings alongside repayments.

Split Loans and How They Are Assessed

A split loan allows you to fix part of your loan and leave the remainder on a variable rate. Lenders assess each portion separately, applying the buffer to the fixed rate on the fixed portion and the buffer to the variable rate on the variable portion, then add the two assessed repayments together to determine total serviceability.

This structure does not improve borrowing capacity compared to fixing the entire loan at the same rate, but it does give you access to an offset account on the variable portion while still protecting part of your repayment from rate rises. For buyers in Chadstone who want certainty on repayments but also want to reduce interest using offset savings, a split can provide both.

When rates are moving, the timing of your application matters as much as the loan structure. A buyer who applies while variable rates are 6.2% and fixed rates are 5.9% will be assessed more favourably than the same buyer applying a month later when both rates have increased by 0.3%. Pre-approval locks in your borrowing capacity based on the rates at the time of assessment, giving you a known budget before you start making offers.

Debt-to-Income Limits and High Borrowing Scenarios

From 1 February 2026, APRA introduced a limit requiring lenders to cap the proportion of new loans made to borrowers with a total debt-to-income ratio of six times or greater. Each lender can make up to 20% of new owner-occupier loans and 20% of new investor loans to borrowers in this category.

For a borrower earning $150,000 per year, a DTI ratio of six times corresponds to a total loan amount of $900,000. Borrowers seeking loan amounts above that threshold may find fewer lenders willing to approve the loan, or may need to provide additional evidence of serviceability such as a history of high savings or minimal living expenses. The DTI limit does not prevent high borrowing outright, but it does mean that lenders are more selective about which applicants they approve at those levels.

In Chadstone, where buyers are often looking at properties in the $800,000 to $1,000,000 range, this limit can come into play for single income buyers or couples with one primary income and high deposit requirements. If your loan amount approaches six times your household income, your borrowing capacity may be constrained not just by the serviceability buffer, but also by the lender's DTI allocation for that quarter.

When to Apply and When to Wait

Borrowing capacity is not static. It changes every time a lender adjusts their product rates, every time your income changes, and every time your expenses or debts are reassessed. For buyers who are close to the threshold between being able to afford the property they want and falling short, timing the application to coincide with favourable rate conditions can make the difference.

If variable rates are expected to rise based on Reserve Bank commentary or wholesale funding cost increases, applying sooner rather than later protects your borrowing capacity. If rates are expected to fall, waiting may improve your position, but only if property prices do not rise faster than your borrowing capacity improves. In a suburb like Chadstone, where proximity to Monash University, Monash Medical Centre, and direct transport links into the CBD keep demand consistent, price growth can outpace any borrowing capacity gains from rate cuts.

A mortgage broker in Chadstone can monitor rate movements across multiple lenders and recommend the right time to submit your application based on the specific property price range you are targeting and the loan structure that suits your circumstances. Call one of our team or book an appointment at a time that works for you.

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