Here's the story: Just bought a house with a large extension at the back which was built in '89 with all proper building regs etc. I've gone to put up new upvc facias etc only to find the neighbours have erected (relatively recently but before I bought the house) a conservatory which is hard up against the side of my extension and uses my facias as part of their flashing. My extension has been built atleast 6 inches from the boundary line which makes their conservatory built not only on the boundary but on my side too. There is a foundation directly next to mine and they have also drilled into my building for other purposes too (hanging baskets etc). Even though there is no obvious sign of damp or subsidence Im not happy about such a liberty being taken and potentially causing value/re-sale problems in the future. Any pointers would be appreciated