Army Corp of Engineers, Department of Natural Resources, and Department of Environmental Management (not sure of the Colorado equivalents).  

The weight will be less and the foot print will be smaller.

I would be sure the agent you choose is specifically well versed in the neighborhood or town you are looking into, and make sure that you review all engineering, environmental (if applicable, and depending on depth of testing you do, commercial or residential, etc.) and inspection reports closely.

My lot is 116' x 50' so the foot print of the building would be no more than 110 x 44.  

A 30 year old HVAC system probably uses the "old" freon, which costs so much more due to government/environmental regulations put in place due to its harmfulness to the planet.

Even if you find a couple of bargains You've got twice the footprint to maintain and rent.   

At minimum you will need to get a geotechnical engineer to look at your souls, an environmental engineer to perform a phase one assessment and a civil engineer to prepare a site plane.

That's from lending to environmental requirements, to required processes, to fees (which can kill a deal from mere inception).... 

However the offer was from a religious organization that wants to expand their footprint in that area of Coronado with a worship center of their own.  

There are no environmental surveys for this property.