Also, though you don't qualify for the residential credit, you do usually qualify for the Investment Credit, which allows you to depreciate the cost of the system over a five-year span, if you read the fine print. 

Originally posted by @Robert Steele: Yes the cities north of Dallas are all good.

From 1965-1990 they had wide swings in their returns (from -48% to +129% in the span of two years) in the past 20 years however their returns have reverted to the mean.

Attention spans are short these days. 

The true power and potential in a business is its age, its name, and most importantly, its life span average cash flow net income. 

And over span of a year scale up in building traffic and audience to hopefully hit a stride of $7k mnthly average. 

Any licensed general contractor would be able to help you, and they would have the span of knowledge you need.

I use this span of metrics (in addition to CoC) to keep pulse. 

By investing in your network by attending meetups, going to grab coffee/lunch, you can seriously shorten the time span it takes to learn from mistakes... because then you can just learn from other's mistakes and tap into their network of contractors/vendors for your own projects! 

The time span and if the first floor can support the second story is what you hire the architect/engineer for.