Just trying to understand what is practical applying the same to a large RV or boat

TENANT PROFILE: tenants are the biggest influence on Neighborhood and Property Class.- If you don't believe us, think about what will happen if you put several Class D tenants in a Class A apartment building.

So choose wisely and good luck I like the passive nature myself of boat and RV storage.

@Polat CaglayanI've never seen a formula but here is a general rule of thumb for multifamily:The class of an apartment refers to the quality of the building, which can be determined by a number of factors, including age, location, and condition: Class A: These are the highest quality apartments, typically built within the last 15 years.

You are simply taking money from some class of people and giving it away freely to another class of people. 

I'm considering leasing out storage space for boats and RVs.  

They typically provide education and also have classes/courses to take.

The Idea is to create a new real estate asset class - the Room Condo. 

And how many classes are there? 

As you seem to be aware, class C is risky.