Most people seeking a mortgage from next year will be restricted to borrowing a maximum of 80% of the cost of the property.
It is just one of a number of new rules from the Central Bank, in order to prevent another property market bubble.
Borrowers will - in the main - also be restricted to borrowing around three and a half times their income.
The new rules will be on top of normal prudent lending by banks, such as stress tests on borrowers.
Deputy Governor at the Central Bank, Cyril Roux, told Newstalk's political correspondent Paraic Gallagher that some mortgages that break the new rules will be allowed.
Karl Deeter , Operations Manager with Irish Mortgage Brokers told Newstalk Lunchtime with Jonathan Healy that 'it will not fix the problem'.
He also said it will encourage and scare people to borrow now in advance. Karl said it is 'uncalled for and unnecessary'
Listen to his full interview here:
