Think of it as your commercial zone in your town.

Key things to consider/evaluate in any geo area: job growth, population growth, major employers in the area (ensure these are permanent ones, f.e. hospital), town/city population size, supply vs demand for housing and what type of housing.

Specifically, I'd like to focus on Days on Market less, Months of Inventory and Median Price to back into which towns near me. 

I have a single family home built in 1970 that is under foreclosure that I am considering buying as my first property....what are some things I should look out for before closing?

They're looking for population centers of 25,000 or more or for the town to be within 25 miles of a population center of 100,000 or more.Not many places hold a candle to the mess that is DC traffic.:)  Best of luckStephanie

Numbers that I'd be interested in seeing over time include: number of these built in your area you're evaluating, the vacancy rate, and how many units have been abandoned (in current state but also over time). 

But now I know how to figure out what can be built on site in detail and get a good rough estimate on costs in a matter of hours.

I've currently been showing an buyer investor foreclosures in Washington and I don't know that part of town at all .... my company has me working with a team that has me working primarily with investors who do flips or buy and holds.   

Is it a big city, small town, middle of nowhere?

If a detatched ADU is built in the backyard, it would need to have a new 100 Amp electrical subpanel right from the main electrical meter installed by the utility company.