Some cost that may vary based on location will be your environmental impact study, your list of cost from the Architect may see a lower cost for the schematics on a smaller project, with similar footprints for all four units, versus varying unit size, and scope requirements (less work, lower cost for A&E), the feasibility study, proforma, 3-D renderings, and other associated cost are going to depend on where this project is going to be built. 

Put a sunset timeframe on it and, in my layman's opinion, you have the primary elements.This is where I am saying you can either deal with the major elements, or hash it out to death legally. 

So even elements that don’t appear damaged can be contaminated.

There's also an element of personal opinion as well based on what the appraiser know about the area. 

In most places for almost anything permanent that isn't ag (storage barn, planting, etc), you will likely need to either engineer to meet floodplain requirements/permitting or find somewhere else.Happy to take a look at it if you DM me the location, my W2 is environmental consulting and I've done floodplain development permitting for about 7 years, mostly in TX and the gulf states.

The best you would be able to get is a Letter of Environmental Protection, which tells everyone you did illegal work then hired a licensed deleader in to fix it.

There are so many items you need to check on a mobile home park in due diligence and we wrote a course around it.Here is a short list of the most "deal-killing" items:1) Test ad.2) Certificate of Zoning from the city or county.3) Phase I environmental report.4) Review of last 3 years of P&L (and tax returns if available).5) Forward forecasting budget.6) Rent roll and payment history.7) Review of the water, sewer and electric systems.8) Size of each lot.9) Confirmation of which homes are occupied and which are vacant.10) Rent comps on all competing mobile home parks.11) Study of the metro market.12) Survey and title.Mobile home parks are much more complicated than they look.

However, according to our By-Law/Master Deed, Garage is considered a part of "Limited Common Elements".Specifically, from our Master Deed: The Limited Common Elements of the condominium shall include any deck, patio, stairs, or garage to which there is direct access to that unit which is appurtenant to same, or any car port to which a Unit has been assigned....These Limited Common Elements are reserved for the use of the Unit(s) either immediately adjacent thereto or for the use of Units to which they have been assigned, to the exclusion of all other Units....Any expenses of repair or replacement relating to said Limited Common Elements, or involving structural maintenance, repair or replacement, shall be the responsibility of the Association, excepting for costs necessitated by negligence, misuse, or neglect of the Unit by a Unit Owner.One day, someone (not anyone I know) likely backed into our garage and crashed the garage doors.

I'd suggest hiring a professional or really digging into this yourself.My background: over 8 years in environmental consulting (13-present), 6-7 yrs doing floodplain development permitting across the country for telecommunications, commercial real estate, and oil & gas.

The project I'm working on is an important element in the redevelopment of our downtown.