I'm reminded of it by a programme tonight called "Impossible Builds". But the one I'm trying to remember was on many years ago. I think it was BBC2 on a Friday night about a man who lived in Newcastle who bought a derelict cottage way out in the wilds, that he intended to renovate on his own, at weekends. The place was virtually inaccessible and he had to carry all his materials quite a distance to the site. He said he was doing it so it would be a peaceful retreat and something to hand down to his children. I just wonder if he ever did finish it. And does anyone else remember it?
I doubt it was impossible builds. More likely to be Grand Designs. Check the website it lists projects going back years and you might find the one you're looking for.