Do you know how construction loans fund extensions?

A construction loan for an extension releases funds in stages as the build progresses, not as a lump sum at settlement.

You borrow against the increasing value of your property as the work is completed. Each payment to your builder triggers a drawdown from the lender after they verify the stage is complete. This protects both you and the lender, but it requires coordination between your builder's payment schedule and the bank's inspection process.

The Progressive Drawdown Structure That Controls Your Build Budget

Most lenders release funds across four to six stages, starting with the base or slab and finishing at practical completion. The builder submits an invoice for the completed stage, the lender arranges a progress inspection, and once approved, the funds are released directly to the builder or into your nominated account.

Consider a homeowner in Bunbury extending their existing home with a new bedroom wing and ensuite. The builder's fixed price contract totals $180,000. The lender structures the loan across five stages: slab and frame at $45,000, lockup at $54,000, fixing at $36,000, practical completion at $36,000, and final inspection at $9,000. Each stage requires the builder to complete the work, submit documentation, and wait for the lender's valuer to confirm progress before payment is released. The homeowner pays interest only on the amount drawn down at each stage, not the full loan amount, which keeps repayments lower during construction.

The timing between stages varies depending on the builder's schedule and the lender's inspection turnaround. Most lenders complete inspections within five to seven business days, but delays occur if documentation is incomplete or the valuer identifies defects. Your builder needs to factor this into their cash flow, and you need to confirm your lender's inspection process before committing to a payment schedule.

Fixed Price Building Contracts Versus Cost Plus Arrangements

A fixed price contract sets the total build cost upfront and defines the payment milestones. A cost plus contract charges the actual cost of materials and labour, plus a margin, with payments made as invoices are submitted.

Lenders across regional WA strongly prefer fixed price contracts for extensions because the loan amount is locked to a defined scope of work. Cost plus contracts introduce variability that makes it difficult for the lender to assess risk or confirm the loan amount matches the completed value. If your builder offers a cost plus arrangement, expect fewer lender options and higher scrutiny during the construction loan application.

Fixed price contracts also require the builder to commence building within a set period from the disclosure date, usually three to six months. If the start date is delayed beyond that window, the contract price may be subject to variation, and the lender may require updated costings before approving the first drawdown. This matters in regional areas where builder availability can push start dates out further than metro projects.

How Interest Accrues During the Construction Phase

You only pay interest on the amount drawn down, not the full approved loan amount. During construction, most borrowers are on interest-only repayment options, which keeps the monthly cost manageable while the extension is being built.

If $90,000 has been drawn across the first three stages, your interest charges apply to that amount only. As each additional stage is drawn, the interest calculation adjusts. Some lenders capitalise the interest during construction, adding it to the loan balance rather than requiring monthly payments. This can suit borrowers who are managing temporary accommodation costs or other build-related expenses, but it increases the final loan balance and the interest paid over the life of the loan.

Once construction reaches practical completion, the loan typically converts to principal and interest repayments on the full loan amount. The construction loan interest rate may differ from the ongoing rate, so confirm both figures during the application process. Some lenders offer a fixed rate during construction that reverts to a variable rate post-completion, while others keep the rate consistent throughout.

Council Approval and the Development Application Timeline

Most extensions require council approval before construction can commence, and lenders will not release funds until you provide evidence of that approval. The development application process varies across regional WA councils, with some approving straightforward extensions within four to six weeks and others taking three months or longer if the design affects setbacks, heritage overlays, or neighbouring properties.

Your builder should manage the council plans and lodgement, but you remain responsible for ensuring the approval is in place before the lender's first drawdown. If approval is delayed, your fixed price contract may expire, or the builder may apply cost escalations due to the extended timeline. Confirm the approval status before finalising your construction loan application to avoid funding delays once the build is ready to start.

Registered Builders and Lender Requirements

Lenders require your builder to hold current registration and appropriate insurance, including home indemnity cover where applicable. In WA, builders working on projects over $20,000 must be registered with the Building Services Board, and lenders verify this before approving the loan.

If you are acting as an owner builder, lender options reduce significantly. Owner builder finance is available, but requires additional documentation including proof of trade experience, detailed costings for materials and subcontractors, and evidence that you have engaged licensed plumbers and electricians where required. Most lenders treat owner builder projects as higher risk, which can result in higher interest rates or lower loan-to-value ratios.

The Progress Payment Schedule and Managing Builder Expectations

Your builder's progress payment schedule must align with the lender's drawdown structure. If the builder expects payment within seven days of completing a stage, but your lender takes ten days to inspect and release funds, the gap creates tension.

Before signing the building contract, provide your builder with the lender's progress payment finance structure and confirm they can accommodate the inspection and release timeline. Some builders in regional areas are accustomed to working with specific lenders and know their processes, while others may need to adjust their standard payment terms. This conversation eliminates surprises and keeps the build moving without disputes over delayed payments.

Most lenders charge a progressive drawing fee for each inspection, typically $300 to $500 per stage. This cost is usually passed to the borrower, so factor it into your overall budget alongside your loan amount and any additional payments for variations or upgrades during the build.

Why a Construction to Permanent Loan Simplifies the Process

A construction to permanent loan covers both the construction phase and the ongoing home loan after completion, using a single application and settlement process. The alternative is a construction-only facility that requires refinancing into a standard home loan once the build finishes.

Most borrowers in regional WA benefit from the construction to permanent structure because it locks in the interest rate and loan terms upfront, removes the need for a second application, and avoids additional settlement costs. You also maintain continuity with the same lender, which reduces administrative complexity during a period when you are already managing builder payments, inspections, and council requirements.

Some lenders offer access to construction loan options from banks and lenders across Australia, which broadens your choice of rates, features, and serviceability criteria. This is particularly relevant if your income structure includes seasonal work, contract roles, or self-employment, which can be common in regional areas.

Call one of our team or book an appointment at a time that works for you. We structure construction funding to match your builder's schedule and your cash flow, and we manage the drawdown process from application through to final inspection.

Frequently Asked Questions