This allows me to cover any major unforseen expenses, for instance a roof replacement or heaven forbid another environmental cleanup.

Commercial appraisals can cost more and the lender may require significantly more due diligence like a phase 1 environmental assessment.

I have my bachelors degree in Environmental Sciences and I'm looking forward to flipping a couple of properties with "green" in mind if it makes sense financially.

I focus on destination type tenants such as barber shops, vet places, regular doctors office, emergency clinics, restaurants, karate schools, fitness centers, environmentally friendly dry cleaners, etc.These are places people HAVE to go to do business.

If you can pre-lease the building, or at a minimum get several good comps showing that leasing will be easy, financing will be easy too.I like that this version has three separate plausible income streams:- Billboard- Building- Land play (I assume, since Denver is hot)Maybe a fourth from upping the zoning too, as @Douglas Dowell said earlier.You might consider running a Phase 1 environmental as part of your due diligence.

If you want to do them for the sake of environmental reasons, that is totally your prerogative.

My dream would be to take older homes and restore them while also making them environmentally friendly.  

Another note the appraiser for the second lender also flagged the property contingent on environmental inspection of septic tank.

What happened was, the previous owner let the septic tank overflow for months until the environmental health dept. shut the home down. 

Any environmental issues?