Like others said,, there's few areas where you could get potential savings..
Most significant are:
Heating / Ventilation / Air Conditioning (HVAC system)
Lighting
and Probably Water Consumption (in hotels)
Here's the breakdown from '99. (but it didn't changed significantly):
Since I can not instruct you about your gas or oil consumption, I can only say something about electric savings..
You can possibly achieve savings in Lighting and HVAC system..
About lighting, I hope I don't need to say that there are various solutions, I mean, that there are various diferent types of lightings that can assure You signifficant savings as opposed to Simple old lighting fixtures that have low power factor (PF). Important thing here is to mention that even though New fixtures can provide good PF, they can still make You, allthough, different type of problem.. Now,, You should not be that affraid,, it's about harmonic distortion that can (and probably will) occur, but solving that issue is still cheaper comparing to consumption with old lighting systems and possible Utillity penaltys for low PF.. Other important thing on topic is wheter You'r buildings electrical installation is old enough that it was build with reduced neutral that can give You more problems when using new lighting that is electronical nonlinear device wich after all and cause this harmonic distortion..
About HVAC, only significant way of reducing of electrical energy consumption is using of Adjustable Speed Drives that will run HVAC pumps and fans.. other savings here are not electrical related..
Conclusion here is,, consulting specialists for specific problem,, or providing us with more details on topic (electrical)..
P.S. I apologize for my english, I'm no native speaker ;)..
Regards,, Alen..