(it is your property now)If they didn't redeem during their proper window they can't and they normally do not put up much of a fight in most circumstances.  

(We are going to have a contractor out to get a better idea on this, but all rooms have holes in walls, none have acceptable flooring, neither bathroom is functioning, the heating system is not functioning, there are broken out windows, though the intact ones are replacement.

It SAYS right on their site its a crime to tresspass or bother tenants in any way.Do YOU knock on the door, peer thru the windows anyway??? 

@Timothy Hood Had a condo years ago, rented fine and had longterm tenant, would get hit with large bill for window replacements, etc. so beware.  

Also need but not urgent 2 windows and the driveway to be redone.My goal is to start flipping and buy/ hold starting next year.

Simple example: your 4 plex roof at purchase has ten years of useful life and replacement is estimated at 10K... try and set aside $1,000 per year on that (same for HVAC, driveway, windows, etc)..

It needs too much work (we are not sure yet how much the rehab will be, working on getting an estimate now. 1800 sq ft needs two baths, kitchen, floors, lots of walls, a few windows, heating system at least.)The bank is asking 99k, it just came on the market.

I'm guessing there aren't too many windows in the unit and attic spaces can get super hot.

For example, no cracked Windows, mold, lead paint, etc.

The house needs it all , its overgrown , roof leaks , siding missing , broken windows , junk car under weeds .