They built that in Pembrokeshire National Park. They didn't bother getting planning permission for it so there was a massive fight with the council (because it's in a national park it's even more of a big deal than if they'd built somewhere else). Yeah OK, you don't to by law get planning permission before starting building but in a National Park it's the norm and is kinda expected that you apply before starting to build because there's so many more limitations to houses in national parks.
Anyway, they did manage to keep it mainly because it was eco-friendly but also because it couldn't be seen from anywhere else as it's surrounded by trees.
I remember when there was the battle over it as it was all over the local newspapers when I was down there on holiday a few years ago.. (I've been going on holiday there all my life so can't remember exactly which year it was...)