Over the same period, the share of mortgages with a 20 to 25-year term dropped from 48% to 30%, figures from Halifax show.
First-time buyers accounted for 46% of all house purchases made with a mortgage in 2015; the same as in 2014, and up from 36% in 2007.
The number of first-time buyers totaled an estimated 310,000 in 2015.
This is an increase of two-thirds (60%) since 2011, from 193,700 to 310,000, but a small drop (0.5%) on last year, which the lender said was because of a lack of supply.
The average price paid by first-time buyers rose by 10% in 2015, from £172,563 to £190,180; the first time it has been higher than the pre-recession peak in 2007 of £174,994.
Craig McKinlay, mortgages director at Halifax, said: “For the second year in succession, the number of buyers getting on the first rung of the housing ladder has reached 310,000.
“Although the average price of the typical first-time buyer home has grown by 10% in the past year, the number of buyers taking that first step onto the housing ladder has been supported by favourable economic conditions; namely, record low mortgage rates, rising employment and real pay growth,” he said.
He added that while affordability has improved since 2007, the average house price to earnings ration is still significantly above the long-term average of 4.0 in many parts of the country.
He warned that this could prevent many potential buyers from entering the market.
The research revealed that first-timers are managing to put down a far bigger deposit than before the recession. In 2015 the average deposit paid by a first-time buyer was £32,927, 88% higher than the £17,499 put down in 2007, and 13% higher than a year ago.
In the South East, the average deposit paid rose by 24% in the past year, from £35,582 to a massive £44,024.
The average first-time buyer deposit is highest in Greater London, at £91,409 – five-and-half times more than the £16,578 put down by first-timers in Northern Ireland.