Used at Stage 3: Arrange finance and budget
How much could you borrow?
Total yearly income before tax for everyone applying.
Applying together? Ask your lender whether you qualify as first-time buyers before choosing.
Site, build, fees and a buffer. Add up your costs.
Savings, gifts and any Help to Buy tax refund confirmed by Revenue. Include site value only if your lender accepts it and it is also in the project cost; site value is not cash to spend.
Use your lender’s rate and term for repayments; the example’s 4% and 30 years are invented.
Optional. A lower lender valuation reduces the amount you can borrow.
Only affects the repayment estimate. Blank hides that estimate.
Use a term from 5 to 40 years.
Your figures stay on this device.
Example: change the numbers to see yours.
Your estimated mortgage, up to
You still need €10,000 for this project: the borrowing limits leave part of the cost uncovered.
| Income limit: 4 × €100,000This limits your mortgage | €400,000 |
|---|---|
| Value limit: 90% × €520,000 | €468,000 |
| Mortgage needed after your contribution | €410,000 |
€520,000 cost − €110,000 contribution = €410,000 needed. No finished value entered, so the value limit uses the project cost.
€410,000 needed − €400,000 estimated mortgage = €10,000 short. Reduce the cost or agree extra funding before committing.
What to do next
Allow for insurance before the first bank payment.
See what cover I needThis is an estimate from the figures you enter; confirm what you can borrow with your lender before you commit.
Monthly repayments and a copy of your result
Monthly repayment at 4% over 30 years
€1,910Repaying the full €400,000 loan plus interest, assuming the rate stays the same. While building, payments depend on how much the bank has released.
How interest works during the buildHow this is worked out
Income limits are four times yearly income before tax for first-time buyers, or 3.5 times for other buyers. This calculator also uses 90% of the lower of your project cost and finished home value, following the lender approach linked below.
It takes the smaller limit, then caps it at the amount your project needs after your contribution. The value rule and which costs count can differ by lender; confirm how yours treats fees, site value and money set aside for surprises.
Lenders also check debts, regular spending and your credit history, so they may approve less. Some loans can exceed the usual limits, but this calculator does not assume you will get an exception.
Sources: Central Bank mortgage measures and Bank of Ireland self-build lending, checked 20 October 2026.
Guides that explain these figures
- Getting a self-build mortgage in Ireland
- How to compare self-build mortgages in Ireland
- Funding a gap in your self-build budget
- Building a house without a mortgage in Ireland: cash first, mortgage after