4years - Really drill down into what is/isn't included in the quote, and read up on the difference between first and second fixes. First fix is basically a watertight shell with electrics and plumbing in place but not finished - you will need to put in switches, sockets, plumb in all sinks, loos and water-using appliances, put down flooring, hang doors, and decorate. It's a lot, and the costs can easily run to as much as the first fix if you are including things like high quality flooring or a kitchen or bespoke cabinetry.
Also, keep interviewing builders until you find two who are reasonable and that you like, and then go see their work in the light. It's weird staring at someone else's house, but have a really long, hard look at the level of finish - how good is the brickwork, the cladding? There are a lot of builders who are "decent enough" out there, but very few who are really superlative. If you're after a contemporary finish, make sure that they can do that - because there are a lot of skills involved in that that some of them may not really use very often if they specialise in more conventional styles of building with render/uPVC. You don't want to spend ££ on modern materials and then have them poorly fitted!
I wouldn't touch a repeat dissolver of companies with a bargepole.
namedy - Hahahaha! I'm nodding along to your post about "Whatever you like, dear". My DH tries to be involved but he's Head of Dept at a uni, and just got a major research grant, so he's basically at work from 7am to 7pm at the moment. He does the cat litter tray in the morning before he leaves, though, bless him!
dust - hoping for good weather and progress for you today!