After talking to a contractor building his mansion in 5- acre lot, zoned agriculture in Gilroy, he gave me a breakdown of the initial expenses:
$350k for the land (flat)
$15k for review of Site Plan by the City planners
$27k for the well water
$30k for the sewage
___ $$$ for the pavement for the driveway and road
$30k for solar
and around $100 per sq ft to build his own structure, 3000 sq ft. For the barn, he used 4 containers, $2k each. He can convert them later on for rental place.
In the bay area, the average cost of building your own house with your chosen contractor/builder is around $400 per sq ft.
For my own modular home, you can view the design and layout with pictures at http://www.azchampion.com , costs:
$54k for 1100 sqt ft , 3BR, 2BA
$10k for delivery
$10k for install
$30k for foundation and car garage
$$$ for land
There is LOFT CUBE made in Germany ($40k for 400 sq ft), with no official rep in the USA and the made in Berkeley net zero home is still being negotiated with manufacturer to cut cost from $110k to half for a 300 sq ft. Examine your options. Containers costs only $2k, talk to a dealer of modular home in your city, contractor for the foundation, and arrange for a seller financing for the land or lease option to buy (do get a real estate lawyer).
The best positive cash flow use of any land are: storage, mobile home park, apartment, multi-unit office-commercial-loft residential.
You may email firstname.lastname@example.org if you want to donate your land to Green Research Institute or Motherhealth, both 501c(3).