The distinction is that 4 units or less is referred to as residential/small multifamily, and 5+ units is referred to as commercial multifamily.Here are the CO state guidelines for "Motels, Hotels, And Multi-Family Dwellings": https://www.sos.state.co.us/CCR/GenerateRulePdf.do?

@John Roberts: This is very gray transaction.. if you actually break the transaction apart (i.e. the sale of the property and the issuance of a loan) and have them as truly two distinct and separate transactions unrelated to each other, then you can do it. 

I wonder if he'll format his show like a regular talk show where he'll have different segments throughout the show and like once a week you'd get 3-5 minutes chatting about new things that are happening here on BP.

Not all states have the distinction.

You better decide that you need to be learning all the time, but there is really just one realistic segment in your life to get a formal post high school education.

There is definitely a distinction between the two. 

Typically turnkeys are priced in the lower segment of the market so that the cash at risk is relatively low.

This is an important distinction as they are covered differently in the State's Landlord-Tenant Act for Mobile Homes.

Even if you keep the financial aspects of the transaction very distinct and clean, there could still be benefit if either party is enabled to participate in a transaction it could not otherwise because of access to the funds of the partner.

It also might not be a meaningful distinction, but my business is focused on buy and hold, rather than flipping, so I don't have plans to sell any of these projects in the next several years, although I likely won't personally occupy them.