ANTIQUES shop boss Michel Andre Morin, 59, is selling his Faversham home for £3.75 million.
Mr Morin and his partner Sam Harpa, 44, own a former lime works and water-softening treatment plant near the M2.
They bought the derelict Grade ll-listed 1930s concrete building in 2005.
Since then, they have spent more than £1.5 million converting it into a luxury six-bedroom, five-storey home with a brilliant white and glass exterior.
It has been dubbed Tracy Island by neighbours, after the hi-tech base of the Thunderbirds.
The pair say 90 per cent of the work is finished – it even boasts its own rooftop swimming pool – but needs another £500,000 to complete.
But they have run out of time and energy.
Mr Harpa told The Sunday Times: "We have ploughed our money into this as we wanted to do the building justice. But really it's too big for just the two of us."
The couple are planning to buy a smaller property near to Mr Morin's Faversham shop and then eventually sail around the world.
Mr Harpa is now hard at work on a new project building a 66-foot concrete yacht.
They are hoping to entice a wealthy Londoner who wants a weekend "trophy home" which is big enough to hold parties for 300 people.
The Lime Works was closed in 1942 because of technical problems, fell into a ruin and became an eyesore.
In the 1960s the water board surrounded it with poplar trees to try to hide it.
Now it boasts the look of an ocean liner with railings around its two roof terraces, treadmill jets for swimming on the spot, and three-storey dining room.
Replica McLaren and Lamborghini racing cars can also be found in the garage (which are not for sale).
The house, in Faversham Road near Throwley, also has its own gym, cinema, library, office and two kitchens and is surrounded by a wood which bursts with bluebells each spring.
The house is up for sale with Savills estate agents.