Construction finance carries risks that standard home loans do not. Cost overruns, builder delays, and interest rate movements during the building phase can derail your budget and leave you financially exposed.
The risks you face when building depend on how your contract is structured, how your lender releases funds, and whether you have realistic contingency planning in place. Many builders in Canberra and Curtin work on fixed price building contracts, but even with that protection, delays in council approval or variations to the original design can push costs beyond what you originally budgeted for.
Why Construction Loans Carry More Risk Than Standard Home Loans
Construction loans expose you to variables that do not exist with established properties. Your lender only releases funds in stages as building progresses, which means you are carrying interest on a growing loan amount while simultaneously managing rent or existing mortgage repayments. If your builder goes into administration halfway through, or if material costs increase mid-build, you may need to find additional funds to complete the project.
Lenders also charge a Progressive Drawing Fee each time they release funds, typically between $200 and $400 per drawdown. These fees add up across five or six progress payments, and they are not always included in initial cost estimates. The other risk is timing. Most construction loan approvals require you to commence building within a set period from the Disclosure Date, usually six to twelve months. If you experience delays securing council plans or a registered builder, you may need to reapply, which can mean reassessment under different lending criteria.
Fixed Price Contracts and Where They Still Leave You Exposed
A fixed price building contract protects you from cost increases for the agreed scope of work, but it does not cover variations or delays caused by factors outside the builder's control. If you decide to upgrade fixtures mid-build, or if a development application is rejected and you need to redesign, those costs fall to you.
Consider a scenario where a buyer in Curtin secured a land and construction package with a fixed price contract. Six months into the build, they requested a change to the kitchen layout and upgraded appliances. The variation added $22,000 to the contract price. Because the loan amount had been approved based on the original contract, they needed to provide the additional funds from savings. The lender would not increase the loan amount without a full reassessment, which would have delayed the next progress payment and halted construction.
Variations are common, and they almost always increase costs. If you are building close to your maximum borrowing capacity, any variation can force you to either pay cash or pause the project while you seek additional finance. That is the exposure a fixed price contract does not eliminate.
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Interest Rate Risk During the Construction Phase
Most construction loans are structured as variable rate during the building phase, even if you plan to fix the rate once construction is complete. That means if interest rates increase during the twelve to eighteen months it takes to build, your repayments on the drawn amount will increase as well.
You only pay interest on the amount drawn down, not the full loan amount, but that drawn balance grows with each progress payment. If rates rise by one percent during the build, the additional cost can be several hundred dollars per month by the time you reach practical completion. For buyers who are also paying rent or an existing mortgage during construction, that increase can strain cash flow.
Some lenders offer interest-only repayment options during construction, which reduces the monthly cost compared to principal and interest. That structure can help manage cash flow, but it does not eliminate the risk of rate movements. You are still exposed to variable rate changes until you lock in a fixed rate or transition to the permanent loan.
Builder Insolvency and How It Affects Your Loan
If your registered builder enters administration before completing your home, your lender will stop releasing funds. You will still owe the full amount already drawn, but you will need to find another builder to complete the work. The cost to complete is often higher than the original contract because the new builder must assess what has been done, rectify any defects, and price the remaining work without the efficiencies of starting from the beginning.
In our experience, buyers who face builder insolvency often underestimate how much it will cost to finish the project. The incomplete structure may not meet the stage of completion you assumed based on how much has been drawn, particularly if the builder was drawing funds ahead of actual progress. That discrepancy leaves you short on both the build and the loan amount.
Builder warranties and home indemnity insurance provide some protection, but they do not cover all scenarios and the claims process can take months. During that time, you are still liable for interest on the drawn amount and any holding costs on the land.
How Cost Plus Contracts Increase Financial Exposure
A cost plus contract means you pay the actual cost of labour and materials, plus a fixed builder margin. This structure offers flexibility in design and材料 selection, but it removes the certainty of a fixed price building contract. If material costs increase or the build takes longer than expected, you absorb those costs.
Lenders are generally more cautious with cost plus contracts because the final loan amount is uncertain. They may require a larger contingency buffer or limit the loan to a lower percentage of the estimated completion value. That means you need to hold more cash in reserve to cover potential overruns, which reduces how much you can borrow or requires a larger deposit.
For buyers building a custom design in suburbs like Curtin, where land values are high and buyers often want quality construction finishes, cost plus contracts are common. The risk is that without a fixed price, your final build cost can exceed your budget by tens of thousands of dollars, and you have no contractual recourse unless the builder has acted negligently.
Contingency Planning and How Much to Set Aside
A realistic contingency is ten to fifteen percent of the total build cost, held as accessible cash or undrawn loan capacity. This buffer covers variations, delays, and unforeseen costs such as site contamination or additional engineering requirements.
Many buyers building in Canberra set aside five percent and assume that will be sufficient. It rarely is. Even on a fixed price contract, delays in council approval, changes to site conditions, or requests for additional work during construction can consume that buffer within the first few months. If you are building on a sloping block or in an area with heritage overlays, the likelihood of unforeseen costs increases.
Your contingency should be separate from your deposit and settlement funds. It should not be money you plan to use for landscaping or furniture. It exists solely to absorb cost increases without forcing you to halt construction or seek emergency finance.
Structuring Your Loan to Manage Risk
The way your construction finance is structured affects how much risk you carry. Some lenders allow you to split the loan into fixed and variable portions once construction is complete, which gives you rate certainty on part of the balance while retaining flexibility on the rest. Others offer the option to lock in a fixed rate during construction, though the rates are generally higher than variable.
The progress payment schedule should align with the actual stages of construction, not arbitrary percentages. A typical schedule releases funds at slab down, frame up, lock-up, fixing, and practical completion. Each release should be verified by a progress inspection conducted by the lender or an independent valuer, which ensures funds are only released when the work has been completed to that stage.
If your lender allows you to make additional payments during construction without penalty, you can reduce the balance and the interest cost as you go. Not all construction loan products offer this flexibility, so confirm the terms before signing.
When to Walk Away From a Project
There are scenarios where proceeding with construction carries more risk than walking away. If your builder is showing signs of financial distress, if the cost estimate has increased beyond your contingency, or if delays mean you will miss your loan approval expiry, you need to reassess whether the project is viable.
Walking away means losing your deposit and any costs already incurred, but it may be less damaging than committing to a project that will leave you financially overextended. If you have not yet signed the building contract, you have more options. Once construction has commenced and funds have been drawn, your options narrow significantly.
If delays are within your control, such as securing suitable land or finalising council plans, address them before they force a reapplication or contract renegotiation. If delays are caused by the builder or external factors like material shortages, document everything and seek advice on whether your contract allows for an extension or compensation.
Construction finance requires active management and realistic budgeting. The risks are higher than a standard home loan, but they can be managed if you structure your loan correctly, hold adequate contingency, and understand where your contract leaves you exposed. Call one of our team or book an appointment at a time that works for you.
Frequently Asked Questions
What is the main difference between construction loan risk and standard home loan risk?
Construction loans expose you to variables like builder insolvency, cost overruns, and interest rate movements during the building phase. Your lender releases funds progressively, meaning you carry a growing loan balance while managing other housing costs, and you are vulnerable to delays or cost increases that do not affect established property purchases.
Does a fixed price building contract protect me from all cost increases?
No, a fixed price contract only covers the agreed scope of work. Variations you request, design changes, or delays caused by factors like rejected development applications are not covered and will increase your final cost. You remain exposed to those costs even with a fixed price contract in place.
How much contingency should I set aside for a construction project?
A realistic contingency is ten to fifteen percent of the total build cost, held as accessible cash or undrawn loan capacity. This buffer covers variations, delays, and unforeseen costs that commonly arise during construction, even on fixed price contracts.
What happens to my construction loan if my builder goes into administration?
Your lender will stop releasing funds, but you still owe the full amount already drawn. You will need to find another builder to complete the work, which often costs more than the original contract because the new builder must assess existing work, rectify defects, and price the remaining work without starting fresh.
Are construction loans variable or fixed rate during the building phase?
Most construction loans are variable rate during the building phase, even if you plan to fix the rate after completion. That means you are exposed to interest rate increases on the drawn amount throughout the construction period, which can strain cash flow if rates rise.
