Top tips to research investment property markets

Investment market research determines which properties lenders will fund and how much rental income they will accept in your application.

Most buyers begin by looking at property listings and suburb medians. That approach misses the data lenders use to approve or decline your application. Vacancy rates, median rental yields, and comparable sales in the same property type all feed into serviceability calculations before you submit a single document. If the research does not align with lending policy, the property becomes unfundable regardless of your deposit or income.

Why lenders distinguish between research and purchase price

A lender assesses two values when you apply for an investment loan: the contract price you agree to pay and the valuation they commission independently. The valuation relies on recent comparable sales, current rental data, and local supply trends. If those figures do not support the purchase price, the loan amount will be capped at the lower valuation figure.

Consider a buyer who contracts to purchase a two-bedroom unit in Aspendale Gardens, relying on the vendor's advertised rent. The buyer submits rental listings for similar units showing higher weekly rents. The lender orders a valuation and discovers that properties of the same age and layout have been vacant for four to six weeks between tenancies, and the median rent sits below the advertised figure. The valuer adjusts the rental assessment downward, which reduces the borrowing capacity by several thousand dollars. The buyer then needs to increase the deposit or renegotiate the price.

This is why researching vacancy rates, median rents by bedroom count, and recent settled sales matters before you make an offer. A property that looks viable on paper can fail serviceability once lender data is applied.

Vacancy rates and serviceability buffers in Aspendale Gardens

Lenders apply a rental shading factor to the income you declare, typically between 20 and 30 per cent depending on the postcode and property type. Suburbs with vacancy rates above three per cent attract the higher shading, which reduces the amount you can borrow.

Aspendale Gardens sits within the broader Bayside LGA, where vacancy rates for units have varied between 2.5 and 3.8 per cent over the past 18 months. Houses have remained tighter, generally below 2.5 per cent. If you are comparing a three-bedroom house near the Waterways wetlands precinct against a two-bedroom unit closer to the Golf Links estate, the rental shading applied by the lender will differ. The house will typically receive a lower shading percentage, which increases the amount of rental income the lender accepts in your serviceability calculation.

You need to confirm current vacancy data for the specific property type you are considering. Aggregate suburb figures mask the difference between houses and units, and between older stock and newer builds. The ATO publishes quarterly postcode-level rental data, and several property data providers offer breakdowns by dwelling type. Relying on advertised rents alone will overstate your borrowing capacity if vacancy is elevated.

Fixed rate versus variable rate for investment property

Investment loan applications are assessed at the product rate plus a three percentage point buffer. A variable rate loan assessed at current pricing would be tested at approximately three points higher. A fixed rate loan is tested at the fixed rate plus the same buffer for the fixed period, then reverts to the variable rate plus buffer for the remaining term.

If you are purchasing in a suburb where rental growth is uncertain, locking in a portion of your borrowing at a fixed rate provides certainty over repayments during the fixed term. However, fixed rate loans typically restrict additional repayments and limit access to offset accounts. Investment properties held on an interest-only basis benefit more from variable rate products with full offset, because the offset balance reduces the interest charged without affecting the deductibility of the loan.

Many investors in Aspendale Gardens hold the loan on a variable rate with interest-only repayments and use the offset account to park rental income and other funds. This structure maintains full tax deductibility while reducing the net interest cost. If you plan to make lump sum payments from other income sources, a variable rate product with offset will typically deliver a lower effective rate than a fixed loan over the medium term.

How the 20 per cent DTI cap affects portfolio growth

From 1 February 2026, lenders can fund up to 20 per cent of new investor loans at a debt-to-income ratio of six times or greater. The cap applies at the lender level, not to your individual application, but it affects approval outcomes for buyers with multiple properties or high existing debt.

If you already hold one investment property and are applying for a second loan, the combined debt across all borrowings is measured against your gross income. Rental income is included after shading, which reduces its contribution to the serviceability calculation. Buyers with a debt-to-income ratio above six may find that some lenders decline the application outright, while others approve at a lower amount or require a larger deposit to reduce the ratio.

This is where local market research becomes critical. Properties in suburbs with strong rental yields and low vacancy improve your serviceability because the lender accepts a higher proportion of rental income. A property in Aspendale Gardens with a gross rental yield above four per cent and a vacancy rate below three per cent will typically support a higher loan amount than a property in a suburb with a three per cent yield and four per cent vacancy, even if the purchase prices are identical.

Negative gearing changes from 1 July 2027

Under the Treasury Laws Amendment (Tax Reform No. 1) Act 2026, net rental losses from residential dwellings acquired on or after 7:30pm AEST on 12 May 2026 can only be offset against other residential rental income or carried forward. They cannot be offset against salary or wages unless the property qualifies as an eligible new build.

Properties held before that date, including those under contract awaiting settlement at 7:30pm on 12 May 2026, remain grandfathered under the existing negative gearing rules until sold. Properties acquired between 12 May 2026 and 30 June 2027 may be negatively geared under existing rules until 30 June 2027 only.

If you are purchasing an established property in Aspendale Gardens now, the ability to offset rental losses against other income will be quarantined from 1 July 2027. This changes the after-tax cost of holding the property and affects the viability of borrowing at higher loan-to-value ratios. Buyers who were relying on negative gearing to manage cash flow during the early years of ownership need to model the difference between offsetting losses against salary and carrying them forward to offset future gains.

Eligible new builds retain access to negative gearing under existing rules. A new build is defined as a dwelling constructed on previously vacant land, or a dwelling that increases the total number of dwellings on the site. A knock-down rebuild that does not increase dwelling numbers does not qualify. If the new build is occupied for more than 12 months before sale to a subsequent investor, that subsequent purchaser loses access to negative gearing.

Calculating investment loan repayments with interest-only and principal-and-interest options

Most investment loans are structured with an interest-only period of one to five years, followed by principal-and-interest repayments for the remainder of the term. The interest-only period reduces the monthly repayment and preserves cash flow, which is useful if you are holding the property for capital growth rather than immediate income.

Lenders assess your application assuming principal-and-interest repayments over the full term, even if you elect interest-only initially. The difference between interest-only and principal-and-interest is not factored into serviceability, so choosing interest-only does not increase the amount you can borrow. It affects your cash flow after settlement, not the loan amount approved.

If you are comparing two properties in Aspendale Gardens with different rental yields, the one with the higher yield will reduce the gap between rental income and loan repayments. This improves your ability to hold the property without drawing on other income sources, particularly after 1 July 2027 when rental losses on established properties are quarantined. Running the repayment calculation at the buffered rate, not the advertised rate, gives you a clearer picture of the cash flow requirement during periods of vacancy or rental adjustment.

Portfolio growth and equity release for second investment properties

Once your first investment property has been held for 12 to 24 months, capital growth and loan principal reduction create equity that can be released to fund a deposit on a second property. Lenders will allow you to refinance the existing loan and increase the borrowing to 80 per cent of the current valuation, subject to serviceability.

If the property in Aspendale Gardens has increased in value, the equity release can cover the deposit and costs on the next purchase without requiring additional savings. However, the rental income from the first property is now shaded and included in the serviceability calculation for the second loan, and the combined debt is measured against the 20 per cent DTI cap.

Buyers who plan to build a portfolio need to research suburbs where rental income is strong enough to support sequential borrowing. Properties with gross rental yields below 3.5 per cent will often limit your capacity to borrow for a second property within two to three years, even if capital growth has been solid. Properties with yields above four per cent and low vacancy provide the rental income buffer that lenders require when assessing multiple investment loans.

Call one of our team or book an appointment at a time that works for you to discuss how market research shapes your investment loan options and borrowing capacity.

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