freefruit - yes, the house was a large 4-bed semi, then it got incompetently extended and a granny flat made out of the original kitchen and outside loo and some of the extension. So we first redid all the heating system (the boiler was 25 yrs old and outside...), then the flat (bedroom, kitchen, lounge, showerroom) ASAP so we could rent it out, then secondary glazing and fixing windows, then the bathroom.
Then embarked on a loft conversion when I was pregnant because the roof really needed repair by then and everyone said to do it before babies. Builder went bust... two years later we have finally done the two bedrooms up there and ds's room, but still have the loft bathroom (currently full of tools etc), three bedrooms, hallways, lounge, dining room and kitchen to go, and that last will be really costly as the whole back of the house needs rebuilding. So another 5 years at least.
The new shed and another bedroom should be done by Christmas, and then we'll do basic decoration and save up for builders for the kitchen.
We knew it would be this long, but it was the only way to afford a house this size in London, and it will be fantastic eventually (it's already lovely and great for parties as all the carpets are pre-ruined!) We don't plan on doing it again, although we might consider doing up a house we aren't living in.
But we did have problems finding a house we wanted that wasn't a total wreck or snapped up instantly by developers, usually wanting to turn it into flats and paying more. We got this one after developers had faffed for a year and finally decided it wasn't quite worth it because of the rebuild needed. Lots of people got put off by the granny flat, but it's made it feasible for us and it's great having a friend so close. Although there was the tenant from hell...
I do rather envy my friend down the road who has the already-done-up version, but without the flat or loft, and we couldn't have afforded it, so that's that.