Building maintenance supervisors have two chief concerns the buildings they watch over and the people employed to service these facilities and the surrounding grounds. Employers depend on these leaders to keep everything running properly and safely. To this end, building maintenance supervisors may do something as simple as changing the light bulb in the entranceway or as complex as figuring out a problem with the wiring of an apartment building. Both internal staff and external contractors or repairmen aid these supervisors with upkeep. While full-time, standard business hours are the norm, building maintenance supervisors may need to work at off times to handle emergency situations. Positions in which the supervisor is expected to oversee several properties can involve traveling between various locations.