This article says:But the regional vacancy rate for apartment buildings stood at only 3%, the Realtors reported, a rate well below that reported by most other markets.http://www.freep.com/story/money/business/michigan/2014/11/25/detroit-realtors-vacancy-rates/70081100/

I closed on the fourplex and as soon as I lifted the tile to begin renovations I discovered the wood trusses and sub-floors are shot and needs complete replacing due to past termite activity and leaks (it's a 100 year old building!).

The claim has still not been resolved after 3 1/2 months because the management company dragged their feet in providing a police report filing (they said they were stood up by police 3x but then I insisted on them just simply going to the police station - duh!

Hope to hear from you.Reggie Truss

To be honest, the best possible answerer is right in your friend’s history: When he applied for Disability, there was some professional who stood up for him and advocated on his behalf.

Builder is able to get all trusses and material now with no wait so that will make the timeline be somewhat on track.

Then tear off roof and trusses in place, frame new walls, we had to sister all floor joists for second floor.  

People tell all the time that the heavier the shingle the better, however more weight is more load on the trusses. 

This is why Real Estate has stood the test of time, measured in centuries, for such. 

If you want to replace it with a pitched roof you would have to frame new rafters or have some trusses built then decking installed on it, then shingle it.