Net mortgage lending was £2bn in August, the highest monthly figure since August 2010.
Lending has been spurred on by a combination of factors including intense competition between lenders, low Bank of England policy rates and rising pay and employment.
The threat of low rates ending is also prompting a wave of remortgaging, which was up 38 per cent on the year to its highest level for four years.
Richard Woolhouse, chief economist at the BBA, said:
“People are putting their money into bricks and mortar while interest rates are low and the timing of a likely rate rise remains uncertain.
“Mortgage borrowing continues to pick up. The August increase is the largest in five years, although borrowing is still some way below pre-crisis levels.
“Remortgaging numbers also continue to be strong, as shrewd homeowners snap up competitive deals.”