Neighbor

https://cityofpetaluma.org/building-permit-requirements/

All work, regardless of whether or not a permit is required, shall comply with the State and Uniform Codes, City Municipal Codes and City Ordinances. Please check with other City of Petaluma Departments for their requirements. Departments may require approval and/or permits for work not mandated to have a permit by the Building Division.

Detached storage building having a floor area less than 120 square feet, no electrical, mechanical or plumbing installed, and no finish on interior walls such as wallboard or pegboard – these buildings will still need to meet zoning setbacks

Structure, Accessory Detached. An accessory building or structure with a minimum separation from a primary structure or building of at least three feet. For purposes of measurement, roof eaves and overhangs, bays, balconies, and other projections shall be considered points of reference. For the purposes of this code, any structure not meeting the separation requirement is considered attached to the primary structure and is subject to the development standards for the primary structure.

Use, Accessory. A use customarily incidental to, related and clearly subordinate to a primary use on the same parcel, which does not alter the primary use nor serve property other than the parcel where the primary use is located.