Rem Koolhaas' 2006 Serpentine Pavilion is on the market as a one-bedroom apartment on a major West London estate agent's website.
The helium-filled balloon and its base have been put up for sale by agency Knight Frank for £750,000.
Whether the acclaimed structure genuinely has the potential to be used as a residential property is unclear.
Any punters with that kind of cash available should visit www.findaproperty.com
However, potential buyers should move fast, as it is understood that one anonymous architectural collector is already in talks to take on Rem's work.
Previous pavilions, which have all been given the £750,000 price tag, have gone to a variety of owners. Toyo Ito's 2002 effort was snapped up by Parkview International, the owner of Battersea Power Station, to use as a marketing suite. by Ed Dorrell