Buildings are set to show up on site on June 23rd and we're using a contractor who we can purchase the buildings from and he will erect them.

If it includes the right to erect a structure then there's your answer...if it prohibits the right to erect a structure that's your answer.

From a Cost standpoint; use todays building cost of say $830,000 for erected buildings; Land of $xxx,xxx; fence $60,000 all around; Electric at $50,000; Security at $50,000 (1 camera for every 6 units, plus license plate cameras and face cameras at entrance/exit); office/utilities $50,000; Grading $??

Does anyone have experience with erecting manufactured, modular, prefab, tiny/micro homes etc here in northern CA?

You apply for a permit to remove the illegally erected walls and fixtures.

Our tenants went ahead and put up a shed in the back yard, without permission, right on the grass. What should I do now? Should I let them keep it but they have to pay for the damage to the grass when they move out? M...

Can you erect a tall fence or more trees?

And I hear this can mean things like erecting barrier walls outside if you are replacing windows, for example, so wind cannot spread any dust.  

Price of steel is up these days but I'd venture to say you can still lay a slab and erect a building for under $20 per square foot assuming you are starting with a good gravel base/lot. 

Last fall Phase 1 we were $3,200 erected for 10 x 15 or 10 x 20.