The bank gave the warning as it announced a 5 per cent increase in pre-tax profits to £125.5m for the first six months of the year.
On Radio 4, Christopher Rodrigues, B&B chief executive said that the housing market was not going to go on rising at the rate it has been.
He said what we're seeing is an adjustment to materially lower interest rates and once that's worked its way through the system house prices will increase along with inflation and along with wages because that's what pays for mortgages.
Mr Rodrigues said that while the slowdown may cool demand for new mortgages, demand for re-mortgaging would remain strong in the low-interest environment.
Mr Rodrigues also moved to quell recent takeover speculation surrounding a move from Barclays, saying that the business was not for sale.
B&B has shown excellent growth figures including a rise in income from its mortgage broking business by 43 per cent to £17.3m, while property revenues climbed 7.6 per cent to £56.8m.