[jyl]

You should call the city on him, so they get there before the work is finished and while the deficiencies are obvious. Or, get a neighbor to do so - but now, not in a month. Reason - for all you know, the next [edit: UN-] permitted addition he does may affect you directly - zero setback and two stories overlooking your backyard, massive eyesore, berlin wall, etc. Even if you are too easy-going to be bothered, that sort of thing makes your house less desirable and thus costs you value. Plus he sounds like a jerk whose chain needs pulling. Also, plant your own privacy and shade trees, some fast-growing variety, in 5 years you can have a middling-decent bit of tree there.