You have a choice concerning the interest:
Either at the rate of income-tax
Or a 7.5% deduction at source, after an annual tax relief of €4,600 for a single person or €9,200 for a couple (plus social security contributions).
It is also possible to opt for the income-tax rate or for a deduction at source, at a sliding tax rate:
Between 0 and 4 years: 35% (plus social security contributions of 11%).
Between 4 and 8 years: 15% (plus social security contributions of 11%).