Construction Loan Guide 2026: How to Finance a New Build in Australia

If you're buying a house-and-land package, building from scratch on your own block, or doing a Knockdown Rebuild, you'll need a construction loan rather than a standard home loan. Construction loans work very differently — and understanding how they work before you sign a building contract can save you a lot of stress and money. Here's everything you need to know.

What Is a Construction Loan?

A construction loan is a home loan specifically designed for properties that don't yet exist. Instead of receiving the full loan amount upfront (as with a standard purchase), a construction loan releases funds in stages as the build progresses. You only pay interest on the money that's been drawn down — not the full loan amount — which keeps your repayments low during the build.

Once construction is complete and the final inspection is passed, most borrowers convert their construction loan to a standard variable or fixed home loan.

How Progressive Drawdowns Work

The defining feature of a construction loan is the progress payment structure. Your lender releases funds in stages tied to specific milestones in the build — typically five stages:

At each stage, your builder invoices the lender directly. The lender may send a valuer to confirm the work has been completed before releasing funds. You don't pay for work that hasn't been done yet — which protects you if the builder runs into difficulties before completing the job.

Interest During Construction

During the build phase, you only pay interest on the drawn amount — not the total approved loan. If your construction loan is $600,000 but the lender has only released $180,000 so far (after the frame stage), you're paying interest on $180,000. This is known as interest-only during construction.

Once construction is complete, your loan switches to principal-and-interest repayments on the full amount. Most lenders give you a 12-month construction period; extensions are available but require lender approval.

The Fixed-Price Building Contract Requirement

Almost every lender will require a signed, fixed-price building contract from a licensed builder before approving a construction loan. This is non-negotiable.

The contract must include:

• A fixed price for the entire build — not a cost-plus arrangement
• A detailed specification of all inclusions
• A build timeline with progress milestones
• The builder's licence number

Construction Loan vs Standard Home Loan

One important difference: the property is valued on completion — meaning the lender approves the loan based on the estimated finished value, not the current value of the land. If your land is worth $400,000 and the build is quoted at $350,000, the lender will assess the loan against the projected completed value, typically $750,000–$800,000. The lender's valuation reflects comparable sales in the area, which may be above or below the simple sum of land and build costs.

House and Land Packages

A house-and-land package typically involves two separate contracts: one to purchase the land, and one to build the house. This means two separate settlements — and potentially two loans.

The land purchase settles first (usually as a standard home loan), and the construction loan kicks in once settlement is complete and the builder is ready to start. Many lenders can combine these into a single loan product, which simplifies the process.

Knockdown Rebuild

If you already own a property and want to demolish and rebuild, a construction loan works the same way. The key difference is that you're not buying land — your existing property is the security. Lenders will assess your equity in the land and add the construction loan on top.

You'll still need a fixed-price building contract and a licensed builder. Demolition costs are typically not covered by the construction loan — you'll pay these separately or roll them into the build cost with your builder. Also factor in the cost of alternative accommodation during the build.

Owner-Builder Loans

If you're acting as your own builder — managing subcontractors yourself rather than using a licensed builder — you'll need an owner-builder loan. These are significantly harder to obtain:

• Maximum LVR is typically 60–75%, meaning you need a larger deposit
• An owner-builder licence is required in most states
• Fewer lenders offer this product
• Some lenders require a construction management background
• Build timeframes are more strictly capped

Unless you have genuine building expertise, most borrowers are better off using a registered builder. The financing access alone usually outweighs the cost premium.

What Can Go Wrong — and How to Protect Yourself

Builder insolvency. If your builder goes bust mid-project, you're left with a half-built house and a lender still expecting repayments. Most states require builders to hold Domestic Building Insurance (also called Home Warranty Insurance) for residential building contracts — thresholds vary by state, typically starting from $16,000–$20,000. Coverage limits also vary by state (in NSW the cap is $500,000). Always verify your builder holds this insurance and understand what it covers in your state before signing anything. Always verify your builder holds this insurance before signing anything.

Cost overruns. A fixed-price contract protects you from the builder asking for more money for base scope items. However, if you make variations — changing tiles, adding a feature wall, upgrading appliances — those extras come out of your pocket. Always budget at least 10% above the contract price for variations and surprises.

Valuation shortfall. The lender's valuation on completion may come in lower than your total land-plus-build cost. If this happens, you may need to contribute more cash or reduce the loan. This risk is greater when building in a new estate where comparable sales are limited. Use a builder with a strong local reputation — lenders take nearby comparable sales into account.

Build delays. Delays past your construction period (typically 12 months) can trigger additional fees or the expiry of a rate lock. Build buffer time into your planning and communicate proactively with your lender if delays arise.

How to Qualify for a Construction Loan

Lenders assess construction loans much the same way as standard home loans, with a few additions:

• Deposit: Most lenders require 5–20% of the total project cost (land plus build). With less than 20%, you'll pay Lenders Mortgage Insurance
• Borrowing capacity: Assessed on your income the same way as a standard loan — the serviceability buffer still applies
• Fixed-price contract: Mandatory, from a licensed builder
• Builder check: Some lenders verify the builder is registered and in good financial standing
• Land settlement: Where land hasn't yet settled, many lenders require land settlement before construction drawdowns begin

6 Tips for a Smoother Construction Loan

1. Get pre-approval before signing the building contract. Know your borrowing limit before you lock in a price with a builder — not after.
2. Budget 10% above the contract price. Variations, soil tests, driveways, landscaping, and utility connection fees add up fast and are rarely included in the base contract.
3. Verify your builder's licence and insurance. Check the licence on your state building authority's website, and ask for a certificate of Domestic Building Insurance before signing.
4. Align your contract milestones with your lender's drawdown stages. Mismatches between the building contract and the lender's drawdown schedule can cause delays and cash flow problems mid-build. Ask your broker to share your lender's standard drawdown schedule with your builder before the contract is signed.
5. Stay in contact with your lender throughout the build. Each drawdown requires documentation. Don't let paperwork pile up — lenders won't release funds without it, and builders won't start the next stage without payment.
6. Plan where you'll live during construction. If you need to rent while building, factor that cost into your total budget. You'll be paying interest on the construction loan and rent at the same time.

The Bottom Line

Construction loans let you build exactly what you want, in the right suburb, with manageable interest costs during the build. But they're more complex than a standard purchase, and the margin for error is smaller. The best protection is preparation: a reputable builder with the right insurance, a fixed-price contract, and a broker who can match you to the right lender before you sign anything.

Written by Amit Narang, Mortgage Broker | Credit Representative 558902 of Outsource Financial Pty Ltd (ACL 384324)

Sources: ASIC MoneySmart; Housing Industry Association (HIA); Master Builders Australia; Commonwealth Bank; ANZ; Westpac