A house which failed to sell despite starring on Grand Designs is to be "given away" to one lucky winner who signs up to Twitter, its owner said today.
Tim Bawtree's "underground house" in Cheltenham won acclaim when it featured on Kevin McCloud's show in 2007 - but has not sold in the current climate.
The £800,000 property will be given away if a website linked to the Twitter page fills up with enough paid-for adverts to meet the asking price.
Owner Tim Bawtree, 38, a software company boss, said the money would be raised not by the house's army of Twitter entrants, but by the advertisers who will (hopefully) buy space on the house's homepage.
The page is similar to the Million Dollar Homepage, which made student Alex Tew a fortune when advertisers bought squares on a giant grid.
The Twitter site, Mr Bawtree hopes, will "drive traffic" to the advertising homepage, and thus encourage enough companies to sign up to pay for the house's asking price.
He needs 90% of the blocks to be filled - at £200 a block - in order for the "give away" offer to be activated.
Mr Bawtree needs to raise £820,000 to cover the price of the house, costs, and a donation to the Services' charity Help for Heroes.
A winner will then be chosen at random from the Twitter membership.
Mr Bawtree, a father of two, said: "Similar things have been done, but there was no hook. The hook here is that people can win a house for free, which will drive traffic from Twitter to the home page.
"People have promoted house competitions on Twitter, but there was nothing where Twitterers exclusively could win.
"This house is like nothing else. You feel secluded even though you are in the middle of a town. Friends say its like being on holiday at home."
The house partly extends under Mr Bawtree's garden and is heated in an eco-friendly way by ground source heat.
Mr Bawtree tried to "give away" the property last year by using a competition question with a £25 entry fee. Thousands entered but the competition was abandoned when a similar house-sale scheme in the West Country fell foul of the Gambling Commission.
Mr Bawtree then changed the competition to a Spot the Frisbee game which his lawyers advised him was safe. But the new idea failed to take off and many players felt aggrieved at the change of rules.