This is my first post here, as perhaps someone as run across this issue when doing this sort of work.
I am redoing my siding and when I ripped off the siding on my back porch (which was an addition) the back wall is all rotted, as well as it was not built right to begin with. Therefore, I have decided to get a building permit, rip down the whole room, and rebuild it bigger with a second bath room. However, does anyone know if I need to get permission from my mortgage holder? Want to ask around first, before I go to them, as sometimes it is best not to say anything.