HSBC has pledged to make £17bn available for UK mortgage lending this year, including £1bn for home improvement loans.
The figure is a £2bn increase on the amount the bank promised in January, reflecting the coalition’s recent proposals to relax planning laws for homeowners.
The government last week announced plans to soften planning rules for a year, allowing homeowners to build up to eight metres into their gardens without council planning permission.
The move is also expected to apply to lofts and garages and will be subject to a month-long consultation.
HSBC said it had already approved £10.6bn of this year’s loan allocation by the end of June.