Building a Home in WA — The Complete Guide to Construction Loans

Building a home in WA involves a very different loan structure to buying an established property — your funds are released in stages as construction progresses, not as a single lump sum at settlement. Understood properly, this can work in your favour on interest costs. Misunderstood, it's where most building-related finance stress actually comes from.

How a construction loan is different from a standard mortgage

With a standard home loan, the full amount is drawn down at settlement and you start paying interest on the whole balance immediately. A construction loan works differently: funds are released progressively to your builder as each stage of the build is completed and inspected, and — importantly — you only pay interest on the amount actually drawn so far, not the full approved loan. Most lenders keep the loan interest-only for the duration of construction, typically 6–12 months, before it converts to a standard principal-and-interest mortgage once the build is complete.

This matters most if you're also paying rent, or a mortgage on an existing property, while building — keeping your construction loan repayments low during the build genuinely helps cash flow at exactly the time you need it most.

Land + build: how the two loans fit together

Most WA new-home purchases involve two contracts: a land purchase, and a separate fixed-price building contract. This is usually structured as either:

• A single loan facility covering both the land purchase and the construction, drawn down in two phases — land settles first, then construction funds release in stages once building begins.

• Two separate facilities — a standard loan for the land, and a separate construction loan for the build — which can sometimes suit buyers who already own their land outright or are building later.

For both the Australian Government 5% Deposit Scheme and Keystart, if you're buying land and building under separate contracts, the combined land price plus build cost needs to stay under the relevant property price cap — it's assessed as one total, not two separate limits.

The progress payment stages

Lenders release funds against a standard set of construction stages, each requiring an inspection (often by an independent valuer or quantity surveyor) before the next payment is authorised:

Stage	Typical % of contract	Released when
Deposit	5%	Contract signature, before building starts
Base/Slab	10–15%	Foundation/slab poured
Frame	15–20%	Frame complete, inspection passed
Lock-up	20–25%	Roof, external walls, windows and doors in — weather-tight
Fixing/Fit-out	20–25%	Internal linings, cabinetry, tiling, rough-in complete
Completion	10–15%	Final inspection, occupation certificate, handover

Expect a progressive drawing fee — typically $300–$500 per drawdown — to cover the lender's costs at each stage. This is a normal, budgeted cost of a construction loan, not a red flag.

Why the payment schedule itself deserves scrutiny

Not all progress payment schedules are equal, and this is genuinely one of the most overlooked risks in the entire process. Some builders structure their schedule to front-load payments — claiming a disproportionate share of the contract value in the early stages to help their own cash flow. The problem: if a builder has already received the majority of the contract value by lock-up stage, their financial incentive to finish the remaining work promptly (or at all, if they run into trouble) drops sharply. Lenders scrutinise this closely and can decline to fund a contract with an unreasonably front-loaded schedule — which is exactly why it's worth having your broker review the payment schedule before you sign the building contract, not after.

Fixed-price contracts, and what happens when costs increase

Lenders require a fixed-price building contract with a licensed builder before approving a construction loan — this gives everyone certainty about the total cost being financed. But "fixed price" doesn't mean the final figure can never change. Two common ways costs move after the contract is signed:

• Variations — changes you request during the build (a different tapware, an extra power point, a layout tweak). Each variation is priced separately and typically needs to be paid for directly by you, on top of the fixed contract sum, rather than automatically added to the loan.

• Provisional sum adjustments — some contract items (like site works or connection costs) are only estimated at contract signing and get finalised once the actual site conditions or requirements are known, which can move the final cost in either direction.

If total costs increase beyond your approved loan amount, you'll generally need to either fund the difference from your own savings or apply to increase the loan (subject to a fresh serviceability and valuation assessment) — which is why it's worth building a contingency buffer into your budget from the outset, rather than approving a loan that exactly matches the contract price with nothing held in reserve.

Government schemes when building in WA

Building attracts some of the strongest government support available to WA buyers:

• First Home Owner Grant: the $10,000 FHOG applies to new builds (including homes you're building yourself), with a property value cap of $800,000 as at the 2026–27 WA Budget — this is one of the few first home buyer supports genuinely aimed at building rather than buying established.

• Stamp duty: vacant land purchases carry their own thresholds — a full exemption up to $450,000 and concessional rates to $550,000 for eligible first home buyers, separate from the established/new home thresholds.

• APRA's debt-to-income exemption: Loans for the construction of new dwellings are specifically exempt from APRA's new high debt-to-income lending limit. Since February 2026, banks have generally been required to keep loans with a DTI of six times income or more to no more than 20% of new mortgage lending. Importantly, eligible construction loans and loans for newly erected dwellings don't count towards this limit. This doesn't change the bank's normal serviceability assessment, but it can remove an additional restriction for borrowers with a high DTI who are building or buying a newly constructed home.

Servicing a construction loan

Lenders assess your ability to service a construction loan similarly to a standard mortgage, but there are a couple of construction-specific wrinkles worth knowing:

• If you're renting or paying an existing mortgage while building, lenders factor that ongoing cost into your serviceability alongside the construction loan repayments — worth discussing with your broker early, since it affects how much you can comfortably borrow.

• Because repayments during construction are interest-only and calculated on the drawn balance (not the full facility), your actual repayments early in the build are typically lower than they'll be once the loan converts to standard principal-and-interest after completion — budget for that step-up, not just the lower interim amount.

Planning to build? Let's map out the finance before you sign a contract.

This article is general information only and does not take into account your personal financial situation, needs, or objectives. It is not financial or legal advice. Progress payment percentages, government grant amounts, and price caps referenced above are typical/current figures at time of writing and vary between lenders and builders — always confirm the specific schedule and current scheme thresholds before signing a building contract. Please seek independent financial and legal advice before making decisions about your home loan or building contract. Ian Freeman is a Credit Representative (Credit Representative Number 439731) of Finsure Finance & Insurance Pty Ltd, Australian Credit Licence 384704.