Last night's episode of Grand Designs was described as the show's "saddest one ever" after a series of problems.
The Channel 4 programme featured Chesil Cliff House, which is based in one of North Devon's most scenic spots - Croyde.
But viewers were captivated - and horrified - as the drama unfolded, not least the revelation that the plans caused a couple to split, Devon Live reports.
One social media user suggested the scenes added up to make "the saddest episode [of Grand Designs] ever".
The house, the brainchild of Edward White, has triple-glazed windows costing £200,000. It boasts a huge circular tower based on a lighthouse, as well as a swimming pool, sauna, steam room and home cinema.
However, eight years after the work started, the house remains unfinished.
Much of Mr White's difficulty was triggered by the failure to secure enough funding, meaning the start date for the project was pushed back four years.
Grand Designs presenter Kevin McCloud learned the cost of the project so far has been around £3 million, with another £2 million or so needed to finish it.
Viewers reacted to the episode on Twitter.
One person said: "Is it just the recession that made banks say no or the building on the edge of a cliff face?"
Another noted: "I want to borrow £1.8 million to knock down a £1.4 million house and build another, on a cliff that's falling into the sea."
The design of the house also stirred much debate, with one person writing: "This guy with his cliffside compound is the worst James Bond villain."
During the show, Mr White revealed he and his partner separated during the project, an event which he thought was probably linked to his grand ambitions for the house.
He still hopes to finish the build but believes it may be some time until he can do so.
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