I run in to the problem a lot. "We are going to make a small hole in you ceiling to get the unit in." Of course this is an exaggerated example but the point is the same. An access hole to me is a giant whole for the customer. In this case we are installing a larger scuttle hole for the customer and everything is well understood.
I ask you; What are your experiences with communication with the customer? How do you explain that you are going to seamingly destroy their house and everything is going yo be okay?