That's a great question, I choose homes that have "written notices" on the door or windows, if the landscaping looks unattended I then look for other signs, like damaged roof, garage, broken windows etc.

Yes but this house is a sfr with I guess an unpermitted basement apartment with own entrance, oil furnace, electric meter, full sized windows.

The house will soon need some major repairs like windows, etc.

I had it chalked it up to broken windows, which were are in the process of repairing.

The former tenants  could give keys to someone else and try to collect money saying they subleased the place.Check all the windows also and make sure locking mechanisms work and have not been rigged for re-entry. 

Getting a lien in Maryland is time consuming and expensive and there is a short window to do so . 

Maybe the renovations are better  (i.e. central heating and air vs.. window units).

When a owner pays for heat, tenants have a tendency to crank up the heat and then open a window to cool down.. 

He has been evading answering the door to my realtor even though he was home - we could see him through the window the previous night... 

To bump this post as I think it will add some great value to the BP community here is a headstart:Home improvement stores: Home depot, Lowes, Menards, ACE, Southerlands, Meeks, lumber liquidators etcProduct types: construction supplies (sheetrock, roofing etc), electrical fixtures, vanities, kitchen cabinets, countertops, flooring, landscaping, Prehung doors, windows, appliances, HVAC etcWho is the best at what?