Rents are rising faster for three bedroom homes than for any other property type.
They show a rise of 4.6 per cent in the year to August compared to an average rise of 3.3 per cent for all homes.
A new index from Landbay shows that the highest rent rises for three bed homes are mostly within commuting distance of London, such as Windsor and Maidenhead (up a remarkable 22 per cent for three bed properties), Southend on Sea (up 20 per cent) and Swindon (up 13 per cent).
But some parts of Britain have seen falling average rents.
Cheshire is down 6.9 per cent over the past year, Aberdeen City is down 5.7 per cent and Buckinghamshire is 3.5 per cent down.
The figures are the first to come from the new rental index produced for Landbay, a buy to let mortgage lender.