I would be really grateful for some thoughts from those with building or structural knowledge on our predicament please!
Our neighbours used some builders a few years ago that didn't follow a party wall award in numerous ways. To cut a long story short I suspect that they have poured their concrete foundations against ours without using compressible layer of material to separate them which was specified in the award, and supposedly asked for by the building control officer. I wondered how this affects us going forward, particularly if we want to make construction alterations in that area (e.g. altering the load on the existing wall or demolishing the wall to rebuild? The award required they set their foundations back from ours. Above ground they apparently didn't follow the award requirements and their wall is built less than 1cm from ours. They have refused to provide their finished excavation details but have ambiguously confirmed the non-compliance in writing. I am wondering if we need to take action now, even if it is initially just to press them for the structural details of what they have done or not done, even if we don't have any losses at this stage because building work is now going to be more complicated in the future?
I'd be grateful to those with more knowledge of building than me to give your thoughts please!