It is also good to ask the HOA how they handle big ticket items (roof, etc...) sometimes they will charge an additional amount for replacing these.Maintenance will generally be less since you don't have to worry about the exterior (usually) and any landscaping.

We are looking into building a large self storage facility but need guidance on all aspects from ground up including financing options.

I would advise using free resources for as long as possible.The links above should give you a good start to start drilling down into what is arguably the most important aspect of a deal, the location.

I assuming the exterior is ok except new roof and painting.The prices reflect materials and labor.

A contractor who is great with kitchen remodels may not have the expertise you need to deal with roof damage.

The home has a garage that is not entirely desirable-- it needs a new roof and some foundation work- plus there is no way to actually park a car in it.

I'm really interested in BRRRR, but the remodeling aspect frightens me as I have little knowledge on how to do it & do it cost effectively. 2). 

and if not how do you make sure that the tenants dont run your water and sewer bills to the roof?

We did a total renovation - New TPO roof, New Windows, New Plumbing, New Electrical, New Base Board Heat, New Window Units, LVP flooring in the common area, Sanded and Painted Hardwood floors in the units, New Kitchens and bath for each unit.

I would make sure whatever you buy the 1st time there are no major concerns i.e roof, septic, furnace, that's pretty much the most expensive things on the list.