Build Loan Calculator

This tool is designed to show how much mortgage repayments relate to build budgets and how much you need for your build project.

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Repayments compared to Building
Financial Tools · Borrowing power

Repayments compared to Building

Move the repayment to see the loan it supports — then check that against what the build actually costs.

Your repayment

A fixed-rate loan, repaid in equal monthly instalments.

Repayment $ /mo
Interest rate
% p.a.
Loan term
years

What you need to borrow

The loan amount that repayment fully pays off over the term, at that rate.

Loan amount
$0

Build cost check

A few questions to see whether your borrowing power (plus any cash on hand) covers the build.

Do you already own the section?
Existing mortgage on the section
$
Current repayment on that mortgage
$
Construction cost
$
Contingency, on construction
Total cost to fund$0
Your borrowing power$0
Cash you're putting in$0
Total funds available$0
That repayment is$0
Compared to your current repayment$0
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Indicative only, not lending advice. Assumes a fixed rate held for the full term with no rate changes, fees, or missed payments — a standard equal-instalment (amortising) loan. Build cost figures are whatever you enter; add your own contingency for the risk you're comfortable carrying. Speak to a mortgage adviser or lender for actual borrowing capacity, which also depends on income, other debt, and the lender's own tests.

Get pre-approved

Once you have an idea if your repayments align with what you want to spend, the next step is to get your lending sorted and approved by the lender. Book a time with a adviser to start your approval process and find out the ins and outs of how banks looking at construction lending.

Find out how to improve your results

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Combining a review of both, your debt and your Kiwisaver is a powerful approach, give you years and additional funds from both ends will snow ball your retirement when done right.