Thanks for all the really useful responses on here.
The problems we had/have for our house and our next door neighbours are affecting us right away and they only began building on Monday this week but the first new house will be less than 100 feet from the end of my garden. Closer than that to next door so on the one hand, we get the noise/pollution/blocked driveways early on so according to their schedule (which I have a copy of) will be finished in May so in reality, probably August. They're having to dig drains right now before they put the service road on top. The head of the digging company promised me to my face that he wouldn't block my driveway or the road but that's exactly what he's doing with a huge digger right now. We explained that my wife is a senior nurse and regularly needs access to get ventilation equipment and dialysis packs for sick children in the area and were assured that she wouldn't be inconvenienced but right now (8.03am) she can't get off the driveway with the life-saving gear until they've put down a temporary bridge to get the digger on to the land they're digging up. But if she parks on the road, that will block their access which they warned us not to do! Some people were threatening to park either side of the road to prevent access but they claimed they had every right to get the police involved if such activities occurred!
It's a bit of a mess right now and it's only going to get worse!
Please keep sending me advice and tips though; all are welcome.