We've had an offer accepted on a house. It's a pretty standard Victorian house layout: double reception room with a kitchen off it at a slight angle. It's a good size but the layout is slightly awkward because of the angles. We're considering doing a small side return extension, going less than 3m out into the garden, and taking down the internal walls to open up a kitchen-diner. Wouldn't want to go bigger because that would mean losing too much outside space.
I think it would make the space a lot nicer, but we couldn't actually be gaining a huge amount of additional square meterage. We'd be putting in a new kitchen, doing the windows and floors anyway, so it's not like the options are doing no work versus doing loads. Not at the stage of getting quotes yet (we haven't had the survey done) but I'm wondering as a general principle whether a small extension is worth the cost and hassle or not? We'd be living there for 5 years at least.
We'd also have to take into account the cost of continuing to rent while the work was done.