There are several ways to structure partnerships. 

I'd like to hear how you have structured partnerships in the past when it comes to buying multifamily/commercial properties. 

How do I structure this deal so it's fair and equitable? 

A quick google search will cast significant doubt on the structure you've been directed to pursue.Link to article

The building structure continues to depreciate over the 27.5 or 39 years.

Luckily structural/engineering reports came back great and inspections didnt call out anything significant.The numbers:Bought the home off market and paid my real estate friend to set up all the contractual information and represent me. 

If so, how did you structure this?

I don't know if this will make you feel any better but even if the roof pancakes flat the interior and exterior walls should support that weight, even though (of course) the house will be totally uninhabitable until the entire roof structure is rebuilt.

If the contractor is doing any significant structural work, or adding on to the existing home/building, then I'd certainly discuss them having their own builders risk policy due to the size and scope of the work they're doing.Hope this helps sir!

Moving forward with this goal in mind how would you suggest structuring a partnership with my friend to do this when I find another deal?