a rather medium poly version of an old apartment building. i made this without any subdivisions because my computer cannot handle any really high res meshes. good luck with it. you can also make the building any height easily using the array modifier. however, its only on the main part of the apartment(where the building actually repeats) to make it easier for use.
really like your building design been work on a few myself. learning how this may help a lot in understanding
:)