Our neighbour is doing a large wraparound extension. It took a few months of back and forth with the council for them to get planning permission, but they finally did.
Building started about 5 weeks ago. It's clear that what they are building is totally not based on the plans that were approved, that our party wall surveyor agreed to, and absolutely contravenes what was approved by planning - eg a 3m high brick wall and pillar at the end where it should have been 2.2m, a vertical 30cm glass window all along the length of the 10m side return extension where it should have been a sloping roof . But it doesn't affect us so much as the neighbour on the other side, who is pretty scared to report them. She's spoken to them and they've sort of vaguely said they'd reduce the height of the brick pillar, but they are basically bullshitting and manipulating her by trying to get her to agree to the glass window. She's worried if she doesn't agree to the glass, they won't change the brick wall, which is what bothers her most.
For us, the only real impact is that our party wall agreement is based on plans which aren't being used, so could affect eg steels and load-bearing capacity. The aesthetics and loss of light etc is a bit worse but not majorly (the impact on us was already massively terrible anyway even with the approved plans tbh but nothing we can do about that.)
But we're so bloody angry that these neighbours, who moved in about a year ago, are basically making a mockery of planning law and just doing what the hell they want. What they're doing would never have got through planning.
Neighbour on other side scared to report them. Would we BU and petty if we did?