Construction loan rates aren't charged the same way as a standard home loan. You only pay interest on what's been drawn down at each stage of the build, which means your repayments start small and increase as more funds are released to your builder.
How Construction Loan Rates Are Applied During Your Build
Construction loan interest is calculated on the progressive drawdown, not the full loan amount. If your approved loan amount is $500,000 but only $100,000 has been drawn for the slab and frame, you're charged interest on $100,000. As each stage is completed and inspected, additional funds are released and your interest adjusts accordingly.
Most lenders offer interest-only repayment options during the construction phase, which keeps your outgoings lower while you're managing the build. Once construction is complete and the loan converts to a standard home loan, you move to principal and interest repayments unless you arrange otherwise.
What Affects Your Construction Loan Interest Rate
Your rate depends on the lender, your deposit size, whether you're building on land you already own or purchasing as part of a house and land package, and your overall financial position. Lenders also consider whether you're using a registered builder with a fixed price building contract or going down the owner builder route.
Owner builder finance typically attracts a higher rate because lenders see it as higher risk. The same applies if you're building a custom design rather than a project home, or if council approval has been delayed. A fixed price contract with a registered builder and council plans already approved generally puts you in a stronger position when it comes to the rate offered.
Consider someone building a custom home on land they've owned for two years. They've got a 20% deposit, council approval is through, and they're working with a builder on a fixed price contract. That scenario will usually attract a lower rate than someone purchasing land and building simultaneously with a 10% deposit and no council approval yet.
Construction to Permanent Loan Structure and How It Works
Most construction loans in Australia are structured as construction to permanent loans. You're approved for one facility that covers the build and then rolls into your ongoing home loan once the property is finished. You don't need to reapply or go through a second approval process when construction is complete.
The interest rate during construction is often slightly different to the rate that applies once the loan converts, depending on whether you choose variable or fixed. Some lenders let you lock in a fixed rate for the construction phase, others keep it variable until the build is done. You can also split the loan once it converts, fixing part and leaving part variable if that suits your circumstances better.
The benefit of this structure is certainty. You know your total loan amount, you know what the ongoing loan will look like, and you're not left scrambling for finance partway through a build. It also means one application, one set of fees, and one settlement process.
Progress Payment Finance and the Draw Schedule
Progress payments are released according to a construction draw schedule, which is agreed between you, your builder, and your lender before the build starts. Most schedules follow a five or six stage structure that aligns with key milestones like base stage, frame stage, lock-up, fixing, and completion.
Before each payment is released, the lender arranges a progress inspection to confirm the work has been completed to the required standard. Once the inspection is signed off, funds are released directly to the builder. You don't handle the money yourself.
Lenders charge a progressive drawing fee each time funds are released. This fee covers the cost of the inspection and administration, and it's usually between $150 and $400 per draw depending on the lender. It's worth factoring this into your overall budget, especially if your build involves more stages than the standard schedule.
In a scenario where a builder requests payment before the lender's inspection is complete, you're not obliged to release funds. The draw schedule protects you by making sure money only moves when work is verified. If there's a dispute about whether a stage is complete, the inspection process gives you something concrete to refer back to.
Land and Construction Package Versus Building on Your Own Land
If you're purchasing land and building in one transaction, lenders treat it as a land and construction package. The full loan amount is approved upfront, covering both the land purchase and the construction costs. The land component settles first, then construction finance is drawn progressively as the build moves forward.
Building on land you already own is slightly different. You're borrowing against the equity in the land plus the proposed value of the completed home. Lenders will usually require a valuation that reflects the expected value once the build is finished, not just the current land value.
For a land and build loan, most lenders require you to commence building within a set period from the date you settle on the land, usually six to twelve months. If you don't meet that timeframe, the lender may reassess your application or adjust the terms. It's not a hard deadline in every case, but it's something to be aware of if council approval or builder availability drags out longer than expected.
Fixed Price Contracts and Cost Plus Arrangements
A fixed price building contract gives you and the lender certainty around the final cost. The builder agrees to complete the project for a set amount, and unless you make variations, that's what you'll pay. Lenders prefer this structure because it reduces the risk of cost blowouts.
A cost plus contract is where the builder charges for materials and labour as the build progresses, plus a margin. This structure is more common with custom builds or renovations where the scope isn't fully defined upfront. Lenders are more cautious with cost plus arrangements, and you may face a higher interest rate or a requirement for a larger contingency buffer in your loan amount.
If you're renovating rather than building from scratch, the same principles apply. A construction loan can cover major renovations, extensions, or a knock-down rebuild. The lender will want to see plans, a builder's quote, and council approval before they'll commit to funding.
What Happens If Your Build Goes Over Budget
If construction costs increase after your loan is approved, you'll need to cover the difference yourself or apply for a loan top-up. Lenders don't automatically increase your approved amount just because your builder has added variations or the build has taken longer than expected.
Some people set up their construction loan with a small buffer built into the approved amount to cover minor variations or unexpected costs. This can be useful, but lenders will only approve what they believe is reasonable based on the contract and valuation. You can't borrow an extra $50,000 just to have it sitting there in case something goes wrong.
If you're using owner builder finance, this becomes even more important. You're responsible for managing the budget, paying sub-contractors like plumbers and electricians, and keeping the project on schedule. Cost overruns are more common in owner builder scenarios, and lenders know that, which is why they price the risk into the rate.
Working with someone who understands how construction funding actually plays out during a build means you can structure your loan with enough contingency to be useful without over-borrowing. It also means having a conversation early about what happens if things don't go to plan, rather than finding out halfway through that your options are limited.
Call one of our team or book an appointment at a time that works for you. We'll talk through your build, your budget, and how to structure your construction loan so you're covered at every stage without paying for more than you need.
Frequently Asked Questions
How are construction loan interest rates charged during the build?
You only pay interest on the amount drawn down at each stage, not the full loan amount. As more funds are released to your builder after each inspection, your interest repayments increase accordingly.
What is a construction to permanent loan?
It's a single loan that covers both the construction phase and converts to a standard home loan once the build is complete. You don't need to reapply or go through a second approval process when construction finishes.
Do I need a fixed price contract to get a construction loan?
Not always, but a fixed price building contract with a registered builder usually attracts a lower interest rate. Cost plus contracts or owner builder finance are seen as higher risk and may come with higher rates.
What happens if my build goes over budget?
You'll need to cover the extra cost yourself or apply for a loan top-up. Lenders don't automatically increase your approved amount if your builder adds variations or the build takes longer than expected.
How does the progress payment schedule work?
Funds are released in stages based on a construction draw schedule agreed before the build starts. Each payment requires a progress inspection to confirm the work is complete before the lender releases funds to the builder.
