Just watched the house tour too.....its very very small for a family of 5!! I'm assuming no dining room, as she didn't show one. The living room looks very small, especially when you think they have nowhere for kids toys downstairs.
The windows look like timber frames, I imagine it will let alot of cold in and possibly damp. Wondering what their survey came back with tbh.
I'm not sure how they will extend, she says extend the bathroom so they are talking a two storey extension - horrendously expensive!! On top of a new kitchen and the new car on finance they will be shelling out for.
Strikes me they have no idea what they've got themselves in for. I can't see them being able to do half of what they want to it.
What they should have done, and I very much doubt they did this, is take a builder round for a further viewing and ask what the possibilities are and rough costs etc. We did this with our house, gave us a general idea of what we could do and what would be achievable with our budget. Bet waz and kez think an extension is a couple of grand ?