Construction Feasibility Calculator

The calculator adds up your full project budget: land value or purchase price, the fixed-price build contract, a contingency allowance calculated as a percentage of the build cost, plus stamp duty, site costs, council and approval fees, and landscaping. Your available equity or deposit is subtracted from that total to find the loan required, and the loan-to-value ratio (LVR) is measured against the total project cost.

The feasibility flag compares your actual LVR against the target LVR you select. If the actual LVR is higher, the calculator shows how much extra equity would be needed to bring the project within target. It also estimates interest payable during construction and a completed value based on a margin over your land and build spend, which varies by build type.

Key assumptions used by the calculator:

• Total project cost = land + build + contingency (default 10% of build cost) + stamp duty + site costs + council fees + landscaping.
• Loan required = total project cost minus your equity or deposit; LVR = loan divided by total project cost.
• Estimated completed value applies a margin to land, build, and contingency: 10% for a new house or major renovation, 15% for a knockdown rebuild, 25% for a duplex.
• Interest during the build assumes an average drawdown of 60% of the loan over a 12 month construction period at the rate you enter, reflecting progressive drawdowns.
• GST, lender fees, and cost overruns beyond the contingency are not included.

This is a general estimate only, not credit advice, a valuation, or a quote. Lenders assess construction loans on the as-complete valuation and a fixed-price building contract, and actual costs and end values vary by project.