The office buildings we are in have pooled utility expense, so our increase in cost is barely perceptible.
Welp, there's the sleaziness every bitcoin operation has to have. Most miners have 50-75% of their revenue eaten up by their power bills, but you've managed to negate this problem by spreading the cost to others without their consent. I'm sure the other businesses in your building(s) would love to know you're running a dozen computers at full power drain 24 hours a day.
Have you projected how long it will take you to get solvent? (remember, revenue =/= profit, common bitcoin mistake) How will you handle the price of bitcoins going down, and the difficulty going up?