I think he was saying that the cheaper ducts that go in the walls have a layer of insulation and plastic around them thats why they don't condensate.  

I feel like in the beginning stage, that is vital..

----CURRENT PROPERTY INFORMATION--****PROPERTY IS LOCATED ONE BLOCK FROM PRIVATE UNIVERSITYProperty built in 1935 (BRICK)4 two bedroom one bath units1 one bedroom unit in basement which is a legal unit (due to age) though no egress windows are presentLaundry area in basement containing 2 washers, 2 dryers4 lockable Storage units in Basement4 car garageCondition: (based upon my knowledge of property, haven't inspected as of yet)GARAGE ROOF: has many layers and though doesn't appear to leak as of yet, it is in need of replacing.BUILDING ROOF: appears to have two or more layers on it, and does not leak, though it will eventually need replacedWINDOWS: 26 windows, mostly crank out old style with small panes.

You want to "control everything, own nothing" so as to be as unattractive a lawsuit target as possible.You want to assure that a lawsuit from one property will not endanger others, or at least not a "large" portfolio of smaller properties.You want to emplace a layer of protection between your entity structure and yourself personally, as well.

§Providing access to vital services: You must provide access to hot and cold water, electricity, heat and fuel (e.g. natural gas).

It's unusual to find an older property without lead paint underneath other layers. 

@Vince Futia Student housing has its own challenges and pets add another layer.  

LLC also offers you gives you a layer of protections.

Go take some layers off of a corner and look??

Adding financing to the mix adds another layer of laws to follow.Happy investing!!