Four out of every 10 first-time house buyers are taking out mortgages of between 35 and 39 years, according to new figures on the first-time buyers' market from the Irish Banking Federation (IBF).
More than half of all first-time buyers taking out 100 per cent mortgages are borrowing for a term of longer than 35 years, the IBF study shows.
The long term and size of the borrowings leave first-time buyers with 100 per cent mortgages most exposed to negative equity - where the mortgage on a property exceeds the value of the house - in the downturn in the property market.
The study, compiled by Amarach Consulting, says almost seven of every 10 first-time buyers with 100 per cent mortgages have fixed their borrowings for between two and three years.
Overall, less than half of all first-time buyers fixed their mortgages for between two and three years, 19 per cent fixed for between four and five years, and 9 per cent fixed for more than five years.
Some 15 per cent of first-time buyers found it difficult to meet mortgage repayments, while just 1 per cent found it very difficult, despite eight interest rate rises since December 2005.
IBF chief executive Pat Farrell said this showed most first-time buyers had "no financial distress in meeting mortgage repayments".
He said first-time buyers were "being cautious" by fixing mortgages. These buyers were "savvy" when it came to borrowing as three out of every four shopped around.
One-third of first-time buyers who took out 100 per cent mortgages had no savings, while 44 per cent said they opted for 100 per cent mortgages because they had no deposit.
The IBF said three out of four first-time buyers were happy with how the mortgage application process had been explained to them, proving that those with 100 per cent mortgages "understood the risk".
"The borrowing is informed and the lending is prudent," said Mr Farrell.
The first-time buyer market accounts for 22 per cent of all mortgages sold in the Irish market, according to the IBF.
An IBF spokesman said 100 per cent mortgages allowed first-time buyers to get on to the property ladder, but that most buyers were unlikely to keep 100 per cent mortgages for their full term.
Amarach based its research on a survey of 500 first-time buyers who purchased their homes between 2005 and 2007.
