Enter the building contract, any loan you already have on the land, and the progress payment schedule. You'll see what you pay each month as each stage is drawn, the interest across the build, and the repayment once it converts.
Once it’s finished—
Monthly interest as each stage is paid
What the calculator follows
A construction loan pays the builder in stages, and you’re charged interest only on what has been drawn. CommBank puts it plainly: while the loan is progressively drawn, it only charges interest on the amount drawn down. Each month the calculator charges interest on the balance drawn so far, including any loan you already have on the land, and adds it up to the end of the build. At completion the whole balance converts to principal and interest over the term.
The simplifications, so you can discount them. Each progress payment lands at the start of its month; one rate covers the whole build; there are no delays, variations or overruns. In NSW the builder’s deposit can’t exceed 10% of the contract and progress payments should be for work done (NSW Fair Trading), so a schedule that asks for more up front is worth querying. Rent or the cost of living elsewhere during the build isn’t included, and for most knockdown-rebuilds it’s the bigger number.
Knocking down and rebuilding?
Our knockdown-rebuild guide covers the order to do it in on the Upper North Shore: approvals in Ku-ring-gai, the loan on the existing home, and what the lender needs before the first progress payment. Our upgrading page covers the move itself. This page is general information, not advice.
Building or rebuilding? We'll set the land and build loans up together.
Three quick taps, then your details, and a real broker replies within one business day.
Do I pay interest on the whole construction loan from day one?
No. Interest is charged only on what's been drawn to pay the builder, so it starts small and grows at each progress payment. CommBank and Bankwest both describe interest-only repayments until the build is finished. Any loan already on the land, or on the house being knocked down, is charged in full from the start.
How much can a builder ask for as a deposit in NSW?
NSW Fair Trading says the deposit must not exceed 10% of the contract price, and progress payments should be for work actually done, not time on the job. Lenders typically pay the builder against a progress payment schedule in the contract.
What if the build runs over budget?
The loan pays the contracted amount for each stage. Bankwest, for one, pays only up to the progress payment schedule amount, so overruns and variations usually come from your own cash. Keep a buffer outside the loan.
How long can a construction loan stay in the building phase?
Lenders set their own limits. CommBank's page says construction must start within 12 months of the disclosure date and finish within 24 months of the first progress payment. Check your lender's terms before you sign the building contract.