Home owners in London stand to earn a small fortune if the Deregulation Bill, currently at its final review in the House of Lords, receives Royal Assent as expected.

It would allow London residents to rent out rooms in their homes, or their entire property, for up to three months of the year.

The proposal would end rules imposed in 1973, by which any home owner wanting to let all or part of their property for under three months had to seek planning permission first.

The rules are policed very differently by individual councils across London.

Lettings agency E J Harris calculates that if the new rules come into play, an owner renting out a two-bedroom apartment could potentially earn anything from £2,000 to over £5,000 per month, depending on location, netting themselves a potential additional income over three months of anything from £6,000 up to £15,000 or more.

At the top of the luxury housing market in locations such as Knightsbridge or Mayfair, an owner of a penthouse could earn themselves £10,000 per week, or up to £120,000 over a three-month period.

If a home owner decided just to rent out a room in an apartment, then rental income for an en-suite bedroom in Knightsbridge could earn them up to £6,600 over a three-month period, while renting out a room without an en-suite bathroom in a typical apartment in inner London could earn around £100 per week.

The firm’s managing director, Elizabeth Harris, said: “Despite the huge sums of money that a wealthy owner in Knightsbridge or Mayfair could earn from a very short-term apartment let or room share, I think it’s unlikely that anyone at this end of the market will choose to enter the short let or room share marketplace.”

She forecast a strong potential market provided by empty nesters whose children had left home, and younger, less affluent home owners, with tenancy demand coming from overseas professionals and those on work secondments.

Airbnb and onefinestay already offer thousands of short-term lets within the UK. Demand for short-stay lets increases further during major sporting events such as Wimbledon.