Does doing the right thing pay in the pocket book. Hell Yes! A recent study of 144 LEED Certified homes that included apartments, townhouses and duplexes and single family homes recently showed a 40% savings in utilities. 64% of the properties surveyed were NOT single family dwellings.
For commercial property owners utilities can make up 35% of a buildings overhead so this savings will go straight to the bottom line. Add to that the fact that you can charge a higher rent for a green rental and you quickly can see the benefits.
Estimates to remodel or build to LEED standards range anywhere from 2-15% of the building or remodeling cost. If it is financed in the same way as the rest of the building, and incentives are thrown in, the investment is cash flow positive from day 1.
For more info on the study go to: http://www.alliancees.org/index.php/RT_PreOcc/