Oh man, I can second the tree removal experts. We have a corner lot with a lot of large mature trees, and we get tree services knocking on our door monthly, telling us we should cut all of our trees down to “protect the house”. We were concerned enough to hire a certified arborist who worked with an engineering firm, who came out for a couple hundred dollars, assessed our trees, and told us all those companies were morons and our trees were just a bunch of nice healthy oaks.