So that's the number that I'm aiming to replace.

Is he a GC and they fall out of his truck bed, is he doing work projects in the dwy, there must be something specific...So first thing is if the other tenant is causing this, then they should be paying for any repairs and tire replacements.

Well besides the hard costs (construction, materials) and soft costs (permitting, architecture, fees, engineering) people often forget holding costs. 

but then I'll have to reinvest and replace the gate access system with their new hardware which I probably won't do..... 

if the carpet is older and could use replacing and it is a smaller room, replace it. 

The person who replaced her will do it, but only if you ask her for it.

The replacement values are drastically different, and so are the premiums.

However, I strongly suggest to seek a structure engineer or architect/drafter that guide/help you on planning and dealing with zoning permits as well.

I'm a software engineer for a company called Accenture but I dabbled in underwriting multifamily on the side.

At 25 years all those roofs are coming due to be replaced.