Some neighbours of mine have been doing some building work for more than 18 months. I have got slightly tired of seeing the skip and all the accompanying mess each time I look out of my kitchen window. I don't know them very well, and would like to keep things friendly, but would I be out of order to ask when it's going to end? The structural building work appears to be complete, so I assume its just internal finishing that's still going on. I have no idea if there is some dispute with the builder or otherwise, but it seems like an excessively long time. The skip is on their property so I guess I have no right to complain. Any ideas?