Had to make a few compromises and do some simplifying. I struggled to fit all the assets into the two texture sheets, I had to use a little less than I originally planned. I split the assets into two groups which are as follows:
Group1: Billboard, Fire Escape, Slum Hut, Slum Roof, Cardboard box 1 and 2, Air Vent, Chimney, Alarm, Small Pipe and Plastic Box.
Group2: Water Tank, Water Tank Stand, Exit Room, Large AC Unit, Skylight, Small AC Unit, Door, Skydish, Aerial 1 and 2, Camera and Light.
I also decided to remove the first building so that my textures wouldn't seem too repetitive. With this done I felt that it was a little easier to split up the surfaces and turn the building assets into a single multi-sub-object material.