The easiest way to buy a duplex as a first home buyer

A duplex offers something unique for first home buyers in Perth: the ability to live in one side while drawing rental income from the other.

That income can reduce your holding costs, increase your borrowing capacity, and in some cases make the difference between getting approved or being told to wait. But duplexes sit in a grey area when it comes to first home buyer concessions, and not every lender will treat rental income the same way during the application process.

Can you claim first home buyer concessions on a duplex in Western Australia?

You can access the First Home Owner Rate of duty on a duplex if you occupy one side as your principal place of residence for at least six continuous months starting within 12 months of settlement. No duty is payable on homes valued up to $600,000, and a concessional rate applies on homes valued between $600,001 and $800,000. The entire duplex value is assessed, not just the side you occupy.

If the duplex is newly constructed or substantially renovated and meets the requirements, you may also claim the $10,000 First Home Owner Grant on homes valued up to $800,000 south of the 26th parallel. You cannot claim the grant if you purchase an established duplex. The FHOG does not require you to occupy the entire dwelling, only that you meet the residency condition.

Consider a buyer purchasing a newly built duplex in Baldivis. The property is valued at $750,000. They plan to live in one side and lease the other to a tenant. Because the duplex is new and under the $800,000 cap, they can claim the $10,000 FHOG and pay concessional stamp duty of around $24,225 instead of the standard rate of $28,033. That combination reduces upfront costs and makes settlement more manageable.

How lenders assess rental income from a duplex you partly occupy

Most participating lenders will allow you to include a portion of the projected rental income when calculating your borrowing capacity, even if the duplex is not yet tenanted at the time of application. The income is typically shaded by 20% to account for vacancies and ongoing costs, meaning 80% of the gross rental estimate is added to your income for serviceability purposes.

Some lenders require a formal rental appraisal from a licensed property manager before they will recognise the income. Others will accept a valuation report that includes a rental estimate. If you are applying under the Australian Government 5% Deposit Scheme, confirm with your broker whether your chosen participating lender will shade rental income and what documentation they require.

In a scenario where the unoccupied side of a duplex in Ellenbrook is expected to generate $450 per week, the lender will typically assess $360 per week as income after shading. That equates to roughly $18,720 per year, which can materially increase how much you can borrow and may allow you to purchase a duplex you would not otherwise have been able to service.

Does the 5% Deposit Scheme apply to duplexes in Perth?

Yes. The Australian Government 5% Deposit Scheme allows eligible first home buyers to purchase with a 5% deposit, with Housing Australia guaranteeing the difference between the deposit and 20% of the property value. No LMI is payable. The scheme applies to both new and established duplexes, provided the property is used as your principal place of residence and the purchase price falls within the applicable cap.

In Western Australia, the price cap is $850,000 for Perth and applicable metropolitan postcodes, and $600,000 for the rest of the state. Whether your duplex falls under the $850,000 or $600,000 cap depends on its postcode. You must confirm the applicable cap using Housing Australia's postcode search tool before proceeding.

Both the purchase price and the lender's assessed value must be at or below the cap. If the duplex is valued at $860,000, you cannot use the scheme even if you negotiated a purchase price of $840,000. The valuation controls eligibility, not the contract price.

How loan structure affects your duplex purchase

Most buyers purchasing a duplex with the intention to occupy one side and lease the other will benefit from splitting the loan into two separate accounts: one for the owner-occupied portion and one for the investment portion. This structure preserves the tax deductibility of interest on the investment portion while keeping the owner-occupied debt separate.

If you take out a single loan and later try to claim a deduction on half the interest, the ATO may disallow it because the funds were not solely used to generate assessable income. Splitting the loan at the time of purchase avoids that issue. Some lenders allow you to split a loan under the 5% Deposit Scheme, while others do not. Confirm this before you apply.

You may also want to attach an offset account to the owner-occupied portion to reduce interest without affecting deductibility on the investment side. This structure gives you control over where surplus cash is directed and keeps your tax position clear from day one.

Off-the-plan duplex concessions and how they apply to first home buyers

If you are purchasing a duplex off-the-plan or under construction in a survey-strata arrangement, you may be eligible for the off-the-plan duty concession in addition to the First Home Owner Rate. The expansion to survey-strata schemes from 12 March 2026 means smaller developments including duplexes are now eligible for the first time.

For pre-construction contracts entered into on or after 12 March 2026, a 100% concession capped at $50,000 applies on dwellings valued up to $800,000. If your duplex is valued at $780,000 and you meet the FHOR criteria, you may pay no stamp duty at all. If the duplex is valued at $850,000, you will receive a partial concession that phases down as the value rises.

The concession runs until 30 June 2028 and is available to buyers regardless of whether they are first home buyers, provided the property meets the eligibility criteria. When combined with the FHOR, this can eliminate stamp duty entirely on qualifying purchases.

What documentation you need for a duplex home loan application

Your home loan application will require the same core documents as any other first home purchase: payslips, tax returns if you are self-employed, bank statements, and proof of savings. If you are relying on rental income from the unoccupied side of the duplex, you will also need a rental appraisal or valuation report that includes a rental estimate.

If you are using a gifted deposit from a family member, the lender will require a signed statutory declaration confirming the funds are a genuine gift and do not need to be repaid. Some lenders will accept 100% gifted deposits under the 5% Deposit Scheme, while others require you to contribute at least a portion of the 5% from genuine savings. Confirm this with your broker before accepting the gift.

If the duplex is new or off-the-plan, the lender will require a copy of the building contract, the deposit receipt, and confirmation that construction is progressing to schedule. For established duplexes, a building and pest inspection report is typically required before unconditional approval is granted.

How to structure your deposit and avoid settlement shortfalls

Under the 5% Deposit Scheme, you are not required to pay LMI, but you are still responsible for all other settlement costs including stamp duty (if applicable), legal fees, building insurance, and lender establishment fees. These costs typically add several thousand dollars to the amount you need at settlement.

If you are purchasing a newly built duplex in a growth corridor such as Byford or Baldivis and claiming the FHOG and FHOR, your stamp duty may be reduced or eliminated entirely. In that scenario, your settlement costs will be lower than they would be for an established property. Factor these costs into your savings plan and confirm the final figures with your conveyancer at least two weeks before settlement.

If you are splitting the loan into owner-occupied and investment portions, some lenders will allow you to draw down each portion separately. This can be useful if you are purchasing off-the-plan and want to minimise interest during construction, but it adds complexity to the settlement process and requires careful coordination with your broker and solicitor.

Call one of our team or book an appointment at a time that works for you. We work with first home buyers across Perth and can walk you through every step of purchasing a duplex, from structuring your deposit to confirming your eligibility for the 5% Deposit Scheme and state concessions.

Frequently Asked Questions