The Central Bank has published four pieces of research on the mortgage market which will form the background to its current review on borrowing rules. 

The Central Bank will announce the results of its review early next month. 

The Central Bank has rules on how much people can borrow to buy a house, and currently the limit is set at three and a half times income. 

A deposit of 10% is also required. However, banks have some leeway to vary these rules for some customers.

These rules are reviewed every year. 

As part of the review, the Central Bank has today published four studies into the mortgage market. 

The studies find that mortgage repayments have fallen from an average third of net monthly income pre-crisis to around a quarter today. 

However, they also show that as house prices have increased faster than incomes, more borrowers particularly in the Dublin region, are borrowing close to the maximum permitted under the rules.

The data also shows borrowers relying on big deposits. 

Over the past five years, the average deposit stood at €87,000, while the average income of borrowers was €82,000. 

First time buyers made up 64% of loans and 40% of loans were for properties in Dublin.