Construction Loan Borrowing Capacity in Australia

Most borrowers can access between $400,000 and $1.2 million for a construction loan, depending on income, expenses, existing debts, and the as-if-complete valuation. Lenders assess your repayment capacity at the loan rate plus a 3% buffer, which is the single largest factor limiting how much you can borrow. A dual-income household earning $180,000 combined with minimal debts could typically borrow around $850,000 to $950,000 for a standard residential build, though this varies between lenders.

Yes, the APRA 3% serviceability buffer applies to all regulated residential lending, including construction loans. If your construction loan rate is 6.5%, the lender assesses your ability to repay at 9.5%. At a cash rate of 4.35% and typical construction loan rates sitting between 6.2% and 7.5%, borrowers are being assessed at roughly 9.2% to 10.5%. This is why borrowing capacity has dropped significantly compared to a few years ago. The APRA website confirms the buffer remains at 3%.

Some non-bank lenders offer higher borrowing limits because they aren't regulated by APRA and can use their own serviceability models. While major banks must apply the 3% buffer, certain non-bank and private lenders assess at lower buffers or use different expense benchmarks. The trade-off is usually a higher interest rate, so you need to weigh the extra borrowing power against the increased cost over the life of the loan. Our guide to non-bank construction lenders explains the differences in detail.

Self-employed borrowers typically have lower borrowing capacity because lenders average two years of tax returns and may discount variable income. If your income fluctuates year to year, most banks use the lower of the two years or a two-year average. Some lenders also apply a higher loading or additional buffer for self-employed applicants. A specialist broker can help identify which lenders treat self-employed income most favourably for construction lending. If you're looking for options with less documentation, see our page on self-employed construction loans.

No, it does not. While you only pay interest on drawn funds during the build, lenders still assess your capacity to make full principal and interest repayments on the total loan amount at the buffered rate. The interest-only period reduces your actual repayments during construction but has no effect on how much the lender will approve. Serviceability is always assessed on the end-state loan, not the construction phase.

From February 2026, APRA requires banks to limit loans with a debt-to-income ratio of 6 or above to no more than 20% of new lending. This means if your total debt (including the proposed construction loan) is more than six times your gross annual income, many banks will decline the application even if you pass the serviceability test. Construction loans are especially affected because the total loan amount often includes both land and build costs, pushing the DTI ratio higher.

Yes, using equity in an existing property can increase your effective borrowing capacity by reducing or eliminating the cash deposit requirement. If you own a home worth $800,000 with $300,000 owing, you have $500,000 in equity. Most lenders allow you to use up to 80% of the property value, giving you $340,000 in usable equity to contribute towards your build. Our guide to construction loan deposit requirements explains how equity works in detail.

Each dependant reduces your borrowing capacity because lenders add estimated living costs for every child or dependent adult in the household. As a rough guide, each dependant can reduce your borrowing capacity by $40,000 to $80,000, depending on the lender's expense model. Lenders use the Household Expenditure Measure or their own benchmarks, and they compare these against your declared expenses, using whichever figure is higher.