Everything You Need to Know About Custom Home Finance

Construction finance for a custom home works differently to a standard mortgage

You're not borrowing a lump sum to buy a finished property. Instead, the lender releases funds progressively as your build reaches defined milestones, and you only pay interest on what's been drawn down. This structure protects the lender and keeps your borrowing costs lower during construction, but it also means your loan application needs to demonstrate that the project is viable, the builder is capable, and the budget is realistic.

Brisbane's established inner-north suburbs see a steady flow of custom builds on subdivided blocks or older demolition sites, particularly in areas like Ashgrove, Wilston, and Kedron where character homes occupy large parcels. The approval process for these projects involves both the lender and council, and timing between development application approval and loan settlement can dictate whether your builder holds their price or reissues the contract.

What lenders assess when you apply for custom home finance

Lenders evaluate three distinct elements: your financial position, the land value, and the construction contract. Your borrowing capacity determines the total loan amount available, which must cover both the land purchase (if not already owned) and the full build cost plus contingency. The land must be registered in your name or settled simultaneously with the first drawdown, and the valuer will assess it as vacant land unless there's an existing dwelling that adds value.

The construction contract must be a fixed price building contract with a registered builder, and it should itemise the progress payment schedule. Lenders will not release funds against a cost plus contract because the final price remains undefined. The builder's insurance, licensing, and financial stability are verified during assessment, and if the builder operates as a new entity without a trading history, some lenders will decline regardless of the director's experience.

Consider a buyer purchasing a 405-square-metre block in Alderley after the existing cottage was demolished. The land contract settled at the current median for vacant blocks in the suburb, and the buyer engaged a local builder for a two-storey custom design. The construction contract detailed six progress payments aligned to slab down, frame up, lock-up, fixing stage, practical completion, and final completion. The lender required council approval, a quantity surveyor's assessment of the contract, and proof that the buyer held a 10% deposit in genuine savings for at least three months. The loan was structured with separate land and construction splits, and the land portion settled on the same day as the first construction drawdown to avoid holding costs on an idle block.

How the progressive drawdown structure operates during the build

Once your construction loan is approved and the land is settled, the lender holds the construction funds in a separate account and releases them according to the progress payment schedule in your contract. Before each drawdown, the lender arranges a progress inspection to verify that the stage has been completed and that the work aligns with the value of the payment being claimed. The builder invoices you, you submit the invoice to the lender, the inspection is completed, and the funds are transferred directly to the builder's account.

You pay interest only on the amount drawn down, not on the total approved loan. During the early months, your repayments might be minimal because only the land component and the first one or two construction draws have been released. As the build progresses and more funds are drawn, your repayments increase accordingly. Once the build reaches practical completion and the final drawdown is made, the loan converts to a standard principal and interest mortgage unless you've arranged interest-only repayment options for a defined period.

Most lenders charge a progressive drawing fee each time an inspection and drawdown occurs, typically between $300 and $500 per draw. With six or seven progress payments across a build, these fees add several thousand dollars to your upfront costs. Some lenders cap the number of inspections included in the approval, so if your builder requests additional drawdowns beyond the contracted schedule, you'll pay extra. Factor these fees into your contingency budget rather than discovering them during construction.

Fixed price contracts and contingency planning

A fixed price building contract locks in the build cost, but it doesn't eliminate the risk of cost overruns. Variations requested after the contract is signed, site conditions that weren't apparent during the quotation stage, or delays caused by weather or supply shortages can all trigger additional costs. Lenders typically require a contingency buffer of 10% to 15% on top of the contracted build price, and this contingency must be demonstrated as available funds or additional borrowing capacity at the time of approval.

In our experience, buyers underestimate how quickly contingency funds are consumed when they make design changes during construction. Upgrading benchtops, adding built-in cabinetry, or relocating powerpoints are common variations, and each one is invoiced separately outside the fixed price contract. If your contingency is exhausted and the build isn't finished, the lender will not increase your approved loan amount mid-construction unless you can demonstrate increased equity or income. You'll need to source the shortfall from savings or delay completion while you secure additional funds.

Council approval and the timing constraint in your loan offer

Your loan approval will include a condition that you must commence building within a set period from the disclosure date, usually six to twelve months depending on the lender. If your development application is delayed at council or if you're waiting on a bushfire or flood assessment, this timeframe can become tight. Brisbane City Council's approval process for custom builds varies depending on the site's zoning and whether the design complies with the relevant code. A compliant application in a low-density residential zone might be approved in six to eight weeks, while a performance-based application requiring neighbour consultation can take three months or longer.

If your loan approval expires before you receive council plans and building certification, you'll need to reapply, and the lender will reassess your application under current policy and interest rate settings. If your circumstances have changed or if lending criteria have tightened, you may not receive the same approval a second time. The alternative is to delay your land purchase until council approval is secured, but that assumes the vendor is willing to extend settlement or that the land remains available.

Why your builder's contract structure affects your borrowing options

Some lenders will only accept progress payment schedules that align to defined construction milestones, while others allow builders to submit their own schedule as long as the payments correspond to completed work. If your builder front-loads payments or requests a deposit exceeding 10%, you may find that certain lenders decline the application. The Australian building industry standard limits deposits to 10% of the contract price, and progress payments should not exceed the value of work completed at each stage.

Owner builder finance is available if you're managing the construction yourself, but the criteria are stricter and the interest rate is typically higher. You'll need to demonstrate experience in construction, provide evidence of trade qualifications or a project management background, and arrange your own progress inspections through an independent quantity surveyor. Most Brisbane councils require owner builders to hold an owner builder licence if the project value exceeds a defined threshold, and your lender will verify that this licence is current before approving the loan.

When custom home finance intersects with land purchase timing

If you're buying land and building simultaneously, the land contract must settle before or at the same time as the first construction drawdown. Some buyers purchase land with a standard home loan and then refinance into a construction loan once they have council approval and a signed building contract. This approach avoids the time pressure of commencing construction within the lender's prescribed period, but it also means you'll pay interest on the full land loan while you're waiting for approvals, and you'll incur refinancing costs when you convert to the construction facility.

The alternative is to structure the finance as a land and construction package from the outset, with the land portion settling first and the construction portion held in reserve. The lender assesses both components in a single application, you pay interest only on the land until construction draws begin, and there's no need to refinance later. This structure works well if you have council approval in hand and you're confident the build will commence within the lender's timeframe, but it's less suitable if your development application is still pending or if you're weighing up multiple builders.

Call one of our team or book an appointment at a time that works for you. We'll assess your position, review your construction contract, and connect you with lenders who are actively writing custom home finance in Brisbane. Whether you're working with a project builder on a modified design or engaging an architect for a fully bespoke build, we'll structure the loan to match your drawdown schedule and make sure your contingency is sufficient before you commit to the contract.

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