In general, all storage buildings (accessory buildings)  require a building permit. If the accessory building has a permanent foundation, however, a permit is required regardless of size. A foundation is not required for an accessory building less than 400 square feet that is not heated for habitable space. If a permit is not required, the property owner is still responsible for locating the accessory building within the minimum zoning setbacks and that its height does not exceed the height of the main dwelling unit.