Accessory Structures

An accessory structure is considered any secondary structure or equipment located on a property, including (but not limited to) the following:
  • Detached garage; 
  • Detached structure (i.e. studio, shed, etc.); 
  • Trellis, arbor or gazebo;
  • Spa, pool;
  • BBQ, outdoor kitchen, chimney, fire pit; and
  • Any other structure in the side or rear yard.
Development Standards

Like your home, an accessory structure has specific development standards regarding setbacks from property lines, size limitations, separation requirements between structures, height limitations, etc. Unless otherwise identified, all accessory structures count towards the permitted floor area allowed on a given property.

Accessory structures may be conditioned (heated) living space and may include a full bathroom (up to 3 plumbing fixtures and a water heater), if desired, but are not permitted to have a kitchen or be rented out as a living unit. Once a structure is deemed habitable or conditioned space, fire sprinklers are required.

Any accessory structure over 120 sq. ft. in size, measured at the foundation, with or without electricity, plumbing and/or mechanical (heating/cool) equipment requires building permits. Structures and sheds which are 120 sq. ft. or less in size without any utilities do not require a building permit, but are still required to comply with accessory structure development standards. Any structure closer than 3 feet to the property line must meet fire rating requirements. For questions on building and fire requirements, please contact the Building Division at (650) 903-6313.