The mid terrace house next to us has come up for sale. We were originally intending to extend the other side of our house, where we currently have a garage. I'm wondering now at the possibility of buying the next door property and knocking through to make a bigger house.
We currently have no mortgage and don't otherwise intend to move. Ever. So the practicalities of the fact that you wouldn't receive as much for the newer house as 2 smaller ones cost isn't a consideration. Nor is the fact that you'd have to get it up to housing regs when separating the property again.
I read a book once where two characters were in a relationship but didn't want to live together. They had houses next to each other and interconnected via a conservatory/rear extension. That's what I'd do.
We did this with our last house; we had a 5 bed Victorian ex-vicarage but oddly a little cottage (2beds) was attached to it so we bought it partly to have the privacy and also to amalgamate the gardens.
The way we did it was to knock a doorway through at ground floor level between the hall of the big house and the kitchen of the cottage, and another door between the two landings.
There was a bit of a palaver about moving electricity meters and things but it worked well.
We had to take out the staircase of the cottage and partially blocked up its front door to make a window.
Twas a lovely house at the end. We also had a massive conservatory built in the angle between the little lhouse and the big house.
I'd say go for it if it's your forever house. Think how much you'll save in estate agents and moving costs!
I have two sets of friends who have done this. One knocked through in the hallways by the front door and upstairs landing, and also in the kitchens at the back of the house, making one kitchen a second living room. You would never know inside that it had been two houses - it's just like a large, double-fronted house.
The other friends just knocked through in the hallways, because they were conscious of the cost and ease of separating the two houses again when their kids all grow up and go.