three room boarding home all electric in my name

[Joe Boggin]

there is a house that went up for sale around the corner from where I work. I made an offer contingent on the appraisal and home inspection but the house is 15k.  The previous owner broke the house up into three rooms.  the only common areas are the bathroom and the kitchen.  The previous owner does not have separate utilities and if I move forward I would intend to keep it that way because of simplicity. 

The tenants have been there for over eight months in each room rents 100 a week/400 a month. From the $1200 gross monthly rent I will be responsible for electric water taxes and insurance. 

Water taxes and insurance will eat up about $200 and electric can eat up close to $500. I'm trying to think of ways that I can reduce my electric costs. This house is a 1000 square-foot row home in the middle of the block. It's not a freestanding single-family home subjected to the winds on all sides. There are only windows in the front and back of the property, not sides.

I calculated that in the summer months if each room has a 5000 BTU air conditioner that would cost about 50 bucks per month per room. In the winter months a 1500 W plug in spacier would cost about 80 bucks per room per month. That's running 24hrs a day. The other appliances are an electric hot water heater, electric oven, and refrigerator.  There is no dishwasher. there is no washer and dryer in the basement.  I do not want to separate all of the utilities. I do not want to have three electric meters and three water meters. These are rooms and not entire apartments. 

Any possible way I can reduce my electric cost would increase my bottom line. Thoughts?  Plastic wrap on the windows in the winter?  Black out blinds in the summer to prevent the sun to heat the room? Timers that can't be tampered with on cooling/heating units that turn on ever 2 hours? Turning down hot water heater in basement to to 115 degrees from 150 degrees?  I'm trying to be as energy efficient as possible!