The building requirements from the street and around the property would have been hard to build a bigger footprint than the current house size.

...........and probably best to have a surveyor pin the footprint of the foundation as well.

Price is $275K, he won't carry anything back45 spaces12 lot rent28 park owned (would sell those to tenants on owner financing/rent to own to get to lot rent)5 Vacantpark homes rent currently $400-425lot rent currently $125- I think market is 175-200, but not many parks around so has been hard to get numbers3 bed houses rent in nearest large(ish) city of Florence SC (30 mins away) rent for $800-900city water and sewersmall park footprint wise, just 2 roads- 1 paved 1 dirt- and all houses in the middle of it, very small footprint, tight parkArea:Marion SC, super small town, but is 10 min from super walmart, 30 min from Florence, that is the nearest MSA (technically Marion is not in one)Marion small, slowly dying town; Florence growing, solid city/townFlorence metro good growth since 2000, like 17%, low unemployment, everything looks solid there.Numbers:I am pro forma-ing it at $150/space lot rent, 40 spaces, $6K/mo, after 45% to expenses is $3,300/mo net/mo... which is $39,600 net/year14.4 cap on property pro forma12 cap on property based on 125/mo lot rent at 40 spaces.

If the it's on the walls, they'll make them remove the mold and patch the walls.If the owners refuse to do the environmental clean up, the underwriters won't approve it.

I also have ideas of building a town home or rental community but there is a lot of work needed with talking to the city, environmental study, financing, low income vs not, etc. 

If Zoning has changed in that neighborhood, and the setbacks have become more restrictive (as many towns in this area of Middlesex County have over the years to discourage more building) then your footprint is NOT grandfathered in the case of a voluntary teardown. 

The Zip code of 48221 is next of the list, here is the link https://detroitmi.gov/departments/buildings-safety-engineering-and-environmental-department/rental-property-informationI believe renovating and selling for top dollar would be in your best interest. https://www.clickondetroit.com/news/defenders/detroit-landlord-jailed-for-code-violations-including-apparent-black-mold-raw-sewage-at-home

The house is a 1971 block, slab on grade with truss hip roof with an L shaped footprint. 

On large projects like the one you are considering (a big one for "new" investor (your words not mine), we would have zoning, financing and environmental contingencies to mitigate the risk of closing and our earnest money.  

I'm guessing they'll look at sewer, parking, traffic, environmental maybe?