I just built my office 
Later I will add computers, furniture, food e.t.c
A faced one problem during my work: when I created a static mesh from BSP (I did it to build my wall with door entrance and walls with windows), my mesh was black.
After about 30 minutes of pain I found solution: open static mesh editor, go to “Static Mesh Settings” expand advanced settings and change Light Map Coordinate Index from 0 to 1.
Cheers!
