Church Building 101 Units of Measure When building your house of worship here are the basics rules of thumb. When purchasing land plan on 1 usable acre of paved, stripped parking for every 300 people.  A paved, stripped parking area should be able to accommodate between 100-115 cars per usable acre and most building codes allocate 1 car per 3 people.  Many local building codes may require islands of planted vegetation within the parking lot which reduces the number of cars per acre  A usable acre is one that does not contain non-buildable ground, such as wetlands, steep slopes, irregularly shaped property, ungradable hills, property that is not accessible, and or property which high tension power lines cross over and where cars are not allowed to drive under these power lines .  Parking Space Dimensions: Standard:  ...