If you'll be sharing a car, home, or other major or real property with others, perhaps as a way to reduce costs or build community, you'll want to consider whether there might be any legal roadblocks to your plan.
For example, zoning and building codes could prevent you from running a business out of your home or converting a single-family home into several units. Or, contractual restrictions in a purchase contract for a planned development or in a lease could limit how you may use your property; for instance, your condo complex's rules might not allow you to turn your front yard into a community garden.
You'll also need to follow the applicable laws for your shared activity. For example, a carshare group will have to make sure the vehicle is registered and licensed, and passes smog requirements. A childcare co-op might have to be licensed by the state or local government.
There might also be tax consequences to your sharing arrangement. For example: