So, as a rule of thumb they might be considered at half the value per square foot as above ground space.

I invest in Detroit from California, and the trust I have with my boots on the ground is the key.

Has anyone ever initiated or been close to ground level in a major redevelopment of a neighborhood?

Plus developing ground up is the extreme of REI.  

These areas will require a good amount of on the ground knowledge that you probably don't want to spend the time getting. 

Election year has masked some real dirt, but not sure how long that stays in the ground.

If your looking for the least amount of risk and biggest bang for your buck I would look for a company that is a reputable turnkey provider thats actually in Detroit and offers things such as an efficient boots on the ground team, all sorts of established local relationships, solid in-house management, an operation that is highly skilled and well versed in section 8, a company that has proven relationships with both out of state and local lenders.

Is there anyone with ground up build experience that is interested in partnering up with us for a project in Davenport Iowa? 

You should always make sure to work with someone boots on the ground who has good relationships with the city so they can make the onboarding process seamless.

When you rehab there is always some can of worms that pops up when you open the walls - the more you squeeze out of the contractor on a line by line basis the more they will up charge when that water line no one knew was there is discovered in some wall it shouldn't be in or the electricians on the original build decided to run the entire houses circuits for the ground floor and second story thru some ugly soffit in the kitchen that looks like it's there for no reason.