Building a detached garage with apartment

[Ben Howard]

Hi my name is Ben. I live in Nashville, TN and am looking to build a detached 2 garage with 2/1 apartment above. I personally went down to Metro to get a building permit because I wanted to make sure what I wanted to do was even feasible for our property, zoning restrictions, etc. Prior to getting the building permit, I had the lot surveyed and site plan drawn up. Before starting the project I talked to a few general contractors that said the type of building I am looking for 25x25 detached garage would be $50K to build. Our plan is 24x24. We are in talks but still looking for a contractor. The project should be funded my early next week as we closed on the loan this week. 

For the numbers on the deal, the loan is costing an additional $235 for a total mortgage/taxes/insurance/etc number of $1120 for $55k in cash. I believe the rental value for the property including a two car garage is in the $1400-$1600 range. 

I'm looking for any knowledge or experience you can impart on a project like this, if you know a contractor that would be good, anything. Thanks in advance!!

[Ben Howard]

Zone Description

Medium density residential, requiring a minimum 6,000 square foot lot and intended for single and two-family dwellings at a density of 6.17 dwelling units per acre.

My lot is zoned R6, which is the description above. The description above is the only reason I thought I would be able to do it though I was still skeptical. So I went do to Metro for the Building Permit and laid everything out on the table for what I wanted to do, site plan with set backs from alley and side yard as well as existing structure, building plans, everything I could think of. I did this myself because I didn't want to get a GC involved if the Metro was going to shoot my plan down. In total, I went down to Metro three different times, each time making slight changes to the plan as they suggested and on the third trip I walked out with a building permit. This was definitely a learning experience. 

Another funny note about the experience...there are persons in there seeking building permits that represent companies building sky scrapers, wheeling in loads of plans on one side of the spectrum, then there's me who is looking to build a 24x24 detached garage on the other side of the spectrum. 

In order for the dwelling to be occupied we had to file a Restrictive Covenant with the Register of Deeds. Below is the first paragraph of the covenant which they give you with your building permit but you have to have signed, notarized and file with the ROD. I took mine down in person, though they say that they'll file it for you from the Permitting office. I opted out since I was taking off work and wanted to know that day the entire process was completed. Once at the ROD, they were able to file the covenant while I was there and give me a receipt that it was completed (it costs $10). 

RESTRICTIVE COVENANT FOR ACCESSORY DWELLING, DETACHED HISTORICAL IN CONSIDERATION of the issuance of a building/use and occupancy permit by the Metropolitan Government of Nashville and Davidson County for a single-family accessory dwelling, detached residence on certain property herein described,

The question regarding the double mailboxes - I assume so, but that never came up. 

I did get a landlord registration form in the mail from Metro the other day, so that seems to be in line with everything I've experienced so far.