@Matthew GrundyThe project didn't work out due to the land having some environmental issues (minor) from gas station next to us.

The environmental violations may be something their not wanting to pay for.

Biggest downside to office is the footprint has been reduced for companies with work from home / limited commute programs.

Skip the attorney, call the state resources dept, or environmental dept.

Seeing that it was a dealership, I am assuming a car dealer here, but regardless you may have an environmental issue on your hands. 

The remediation company will not give an absolute move out recommendation, because they refer to a third party company for environmental assessment (minimum 300-1200 not covered by insurance), but the tech has indicated it would be a good idea for them to move out for 5-7 days.  

So a 10 unit building, 5 up/5 down, is probably looking at about a 60x60 building footprint, minimum, plus common area, plus compressors/utilities, plus parking for whatever mandate is in your zoning (2 per unit, or maybe more).

Such are not marketable.Contaminated properties are high on the list to stay away from, environmental issues can be very expensive to clean up. 

You would obviously have to factor in demo costs of existing structure, any environmental abatement etc, however that would be my first approach on establishing quick value.  

I could see footprints from people who had walked through previously!