An EZ-permit through Land Use (Room 307) is needed to put in a patio that is flat to the ground - must bring in a property survey. It is just suggested that the patio is approximately 4 feet from the property line so there are no drainage issues with the neighbor's property.
If the patio is going to be on footings then a building permit is needed.
This refers to a patio in the backyard that is to be used for sitting outside. This is not a "patio" or concrete slab that will be used to park a car.