It's come up in the searches that the house next door to the one were buying has had planning permission granted for a large extension. I've looked at the plans and it doesn't look like it will impact on us, it's the other side so not our boundary and no new windows on our side. I know there will be noise and mess but is there anything else I need to think about? I think it's a bit underhand of the vendors not to have mentioned it and I'm worried I've over looked something.
If it's not going to impact on you directly then I don't think it's an issue at all. Any house you buy could apply for planning permission the day you move in, which may or may not impact on you but may well be granted, so I wouldn't be worrying about this one. I don't particularly think your vendors are being underhand not mentioning it either.