Definitely recommend reaching out to the city first to confirm what permitting would be needed for added square footage.

He *seems* to be making an effort to square people away and talks all sincere, but everything we've seen to this point I won't trust a word of it until my balance in full is wired into our checking account.

The best will often ask for nothing until they set foot on the jobsite and really start with site set-up and demo. 

or is this a more historical foot trafic area? 

As you do this more often, you'll be able to keep a spreadsheet of per square foot prices for materials and labor to get things done and you'll be able to estimate this yourself.

Some of my favorites are Portage Park, Avondale, Logan Square, Humboldt Park, Albany Park, Irving Park, the south parts of Rogers Park that boarder Edgewater/Andersonville which are getting high income renter pushover.

Like many have said here, consumables are reasonable for tenants to foot the bill and replace themselves.  

ON my latest subdivision I built we have a 15 foot right of way for the major sewer line on one lot and we let the owners know that they may want to do just light landscaping or just bark dust it/ or out east I guess its pine straw. 

When the tenant leaves or there is an eviction, you will be stuck footing all the bills with a low likelihood of recovering it.

It's a great way to get your foot in the door in your local market and offset your mortgage while building equity.