It would be 2 upper units in an older home so probably not great insulation but with new windows and about 1200 sq ft.

If the house needs a complete rewire, replumb, new hvac, all walls brought to current insulation codes, and then all new flooring, drywall, insulation, kitchen, baths, doors, trim, etc...

But when I say full gut and rehab I'm talking: taring everything down to the studs, updating plumbing and electrical throughout, probably upgrading the panel, adding duct work for heating and cooling, new mechanicals (boiler, A/C, etc) , hardwood floors, new kitchen, new dry wall and insulation, paint, finish work, etc.

My wife just texted me asking why the workers busted a hole through the ceiling instead of going into the attic to install insulation.

Roof leaks: Bad roofing job and poor flashingIce damns: Poor insulation/ventilationThere are other reasons for mold in a house, but the most important part is to get rid of it permanently.

They didn't remove and replace drywall/insulation (besides one small section of drywall).

The only immediate repairs I saw where the chimneys need retoppi g, the dtiveway needs redoing and the basement qindows need to be boarded in and insulated. the rest is cosmetics as long as the residents stay.Originally posted by @Jim Goebel:@Brian FooteHiIt's going to be hard to say precisely without knowledge of your market however those rent numbers are pretty good if I'm seeing the $1600+ for what you're getting into the property for.The 'gotchas' that I see that I'd want you to really be comfortable with would be that repair cost number - this would have to be a pretty light rehab where you're maybe doing a facelift, etc. 

Unless you insulate EVERYTHING and put in good electrical heaters and have a professional do the work then think twice about it.

You probably just need better noise insulation for your home.If there are several complaining, I have heard of a case where a whole neighborhood bang together and sued the landlord for renting the house out to gangsters.

The price will be driven by the number of fixtures and lengths of runs of piping, but I just can't imagine it costing it anywhere near $30 to $40k.For a similar project for me in Kansas City, re-plumbing new water supply lines would be <$10k.I think big risk is how much water damage, mold remediation, drywall patching, insulation, framing & other finishes needs to be replaced?