Gas water and electric?    

We are going to sub-meter the electricity. 

(A) A landlord who is a party to a rental agreement shall do all of the following:(1) Comply with the requirements of all applicable building, housing, health, and safety codes that materially affect health and safety;(2) Make all repairs and do whatever is reasonably necessary to put and keep the premises in a fit and habitable condition;(3) Keep all common areas of the premises in a safe and sanitary condition;(4) Maintain in good and safe working order and condition all electrical, plumbing, sanitary, heating, ventilating, and air conditioning fixtures and appliances, and elevators, supplied or required to be supplied by the landlord;(5) When the landlord is a party to any rental agreements that cover four or more dwelling units in the same structure, provide and maintain appropriate receptacles for the removal of ashes, garbage, rubbish, and other waste incidental to the occupancy of a dwelling unit, and arrange for their removal;(6) Supply running water, reasonable amounts of hot water, and reasonable heat at all times, except where the building that includes the dwelling unit is not required by law to be equipped for that purpose, or the dwelling unit is so constructed that heat or hot water is generated by an installation within the exclusive control of the tenant and supplied by a direct public utility connection;(7) Not abuse the right of access conferred by division (B) of section 5321.05 of the Revised Code;(8) Except in the case of emergency or if it is impracticable to do so, give the tenant reasonable notice of the landlord's intent to enter and enter only at reasonable times.

I recently bought a house and the owner had a bunch of liens on the house, but apparently gas and electric companies don't put liens on properties around here.

The 50/50 split doesn't make a lot of money, but it can cover the cost of water and electricity. 

Also, BUY bed bug proof mattress covers for each mattress.

I extended the AC to that area, built up and soundproofed then tiled the floor, insulated the walls and added phone lines and more electrical outlets.

Then the tenants told me at the end of their tenancy they were getting $300/per month electric bills.

Can you imagine what kind of bugs we'd have if she was in there during the summer?

Plumbing, electrical, HVAC, etc.