., possible old plumbing and electric.  

I based my numbers off what my annual tenant was giving, plus any additional expense like electric and cable I would have to pay for now. then ran my numbers.

A radiant system is also suitable for connection to solar thermal hot water, so you could effectively heat the house with solar energy (not to be confused with photovoltaics), using a tank or in-line water heater as your backup heat source.The boiler itself, if it is a newer, direct vent, condensing, natural gas unit, it could be up to 95% efficient.  

@Joe FreyIf you are redividing the property into two units, why not simply put separate electrical and, if present, gas entrances into the second unit?  

The places i've seen has the plumbing/electrical/HVAC so its a fair simple go.I will admit I spend $2000 on cameras, and exterior lighting.  

Best way is to obtain authorizations for release of credit, tax returns, assets and liabilities, then send copies or get several originals to use, mail them  and obtain information directly from the source, this cuts out the chance of fraudulent statements.You also need to underwrite the type of business, what hazards are present, toxics, fire, insurance coverage, competition with other tenants, traffic counts, environmental laws applicable to them as well as your infrastructure being sufficient for tha use.....electrical, plumbing, traps, fire codes, etc. 

This ALONE is about 50KYou have not even touched electrical, plumbing, painting, roof, hardware, furnace, water heater, landscaping, I seriously doubt the repairs will be 75K

If you see yourself totally hands-off, spend your energy finding the best pm companies in your area to partner with.

Another issue I ran into on a property was when I wanted to change the use (industrial to residential) I had to bring the current structure up to the new energy code.

If not I would spend my energy finding the couple best PMs in the area and let them recommend contractors.