Paint it green? On a serious note: Heat the building with server heat, cool it using grey/waste water instead of air conditioning, add insulation and let outs

Paint it green? On a serious note: Heat the building with server heat, cool it using grey/waste water instead of air conditioning, add insulation and let outside air in at night, put plants all around, keep the lights off unless you're working in an area, etc. There's too many possible methods without knowing the setup and layout of your facility. Hell, just start carpooling and that'll be greener already. Maybe see if the company will throw in for gas or tolls for any vehicle that shows up with 3 or more employees in it.