With Londoners squeezing into smaller and smaller properties, one owner has spotted an opportunity - selling off the loft as a home.
Next week, the two small loft spaces above a shop in Greyhound Lane, Streatham Common, will go under the hammer, with a guide price of just £5,000.
The space is being sold as a 125-year lease through Auction House London.
"We are seeing a lot of this sort of thing coming up at auction," the firm's Andrew Binstock tells Metro.
You'll never guess what's behind this hole in the wall
"Leaseholders are selling the hope of potential future development and if a young buyer is brave and clever enough, and manages to get planning permission, this is a very cheap way on to the property ladder."
Turning the small space into a home will take some ingenuity. For a start, there's currently no proper way of accessing the space, which means that an extension to the existing communal staircase will be required.
There's currently no planning permission for the conversion, and the owners of the existing leasehold flats in the building would probably need to give permission - most likely in return for a payment.
Tiny London alley sells for over £400,000
Particularly in London, the smallest spaces are now being seen as potential homes.
Last year, for example, a 13-foot-wide alleyway between two Shepherd's Bush houses was sold for £400,000, with planning permission for a two-storey house. There were nine offers at or above the asking price.
Earlier last year, a house in East Dulwich that's just ten feet wide sold for a whacking £800,000. And in 2014, a property in Haringey sold for £200,000, despite measuring less than seven feet wide.
Bizarre property is just 55 inches wide and up for sale
New homes in the UK are the smallest in Europe - just 76 square metres on average, compared with 109 in Germany, 113 in France and a palatial 137 in Denmark.
However, some tiny homes are delightful, as our recent round-up shows. Pick of the bunch is probably the 18th century Round House near Bristol, which manages to pack a kitchen/living room, bedroom and shower room into a circular building that's just 11 feet across.