The chief economist for Nationwide Building Society said there was an “increased trend” towards stretching out mortgages with 52 per cent of loans taken out today set to last more than 25 years, compared to 40 per cent in 2007.
Mr Gardner said the longer repayment period was seen as a better option than lowering monthly payments through interest-only mortgages.
He added that the shift towards longer-term loans may also reflect the fact that people were living and working longer.
Mr Gardner’s comments came as data from Nationwide showed that financially squeezed first-time buyers were struggling with house prices 4.6 times their average earnings.
Despite well-publicised government initiatives to ease deposit requirements, the average loan being taken out by first-time buyers was 80 per cent, below the 95 per cent maximum level.
First-time buyers can expect repayments on a typical mortgage to account for 19 per cent of monthly earnings.
The figures show that first-time buyers were returning to the housing market. The number of loans approved for them rose by 32 per cent to 73,700 in the third quarter of 2013, compared to the same period in 2012.
Mr Gardner said the “sustainability” of the first-time buyer revival would depend on how the economy performed, particularly if employment prospects continued to improve.
73,700 - number of first-time buyers in Q3 2013
32% - rise in the number of first-time buyers compared to Q3 2012
4.6 - house price multiple to average earnings, above a 20-year average of 3.6 times
19% - amount mortgage repayments take from average monthly earnings
Adviser comment: Ian Broadbent, director of Lincolnshire-based Blue Sky Mortgages, said: “I would expect the natural retirement age would move up to 70 so all financial decisions move upwards. But what is more worrying is the difference between repayments on 25 and 40-year terms. Stretching the terms suggests affordability is a problem in the first place.”