Brian - I've added air conditioning to HVAC when I needed to replace the gas heater in houses.

I was doing Hard money for Gas Stations and strip malls.

To get operating costs: Most places the city water authority will give you 1&2 year averages (as will the gas and electric companies to determine other landlord provided utilities); your insurance agent should be able to give you a pretty close per door quote on insurance; you should be able to call the current trash provider for a price.

Jacob I should have labeled "RGE" better as that is our Gas and electric estimated at $120/month.

Also, our gas and electric bills did not acknowledge our address; rather, the bills both showed our address as two numbers off. 

Here's a PARTIAL list:Office rentComputers, printers & softwareInternet & phone billOffice furnitureOffice supplies: paper, postage, ink, etc.Office liability insuranceAuto expenses: monthly payment, insurance, gas, maintenance, registration/plate feesBroker license fees: annual, monthly board & MLS fees, continuing education fees, E&O insuranceEquipment: lockboxes, signs, etc.Business income tax preparation and paymentsStaff payroll & payroll taxes Time Tasks: answering phones, calling past due tenants, scheduling tours, taking marketing pics, processing those pics, writing ads, researching rent amounts, posting ads, explaining to owners how rent determined & showing where ad posted, opening & processing mail, posting payments, bank deposits, scanning documents & posting to owner & tenant portals, explaining accounting to owners so they understand their monthly statements, taking pics/videos of repairs, finding reputable handymen and contractors, confirming they're properly licensed & insured and tracking annually, verifying repairs done properly, processing invoices for utility bills, repairs, taxes, city inspections, scheduling periodic property evaluations/inspections with tenants that don't want strangers in their homes, explaining to owners why taking so long, and more & more & more...

If not (ie two full-time working spouses) your only other option is going into land conservation deals, solar deals, or oil and gas deals - all of which have some risks.Explained in a different way...1) There are ordinary/W2/active income on one side.

Everyone else has mentioned the noise but I'd also be worried about water leaking from the top unit into the bottom unit.

My question is should we include internet, water, gas, and power?

Is it leaking or just unstable?