Walnut Creek Regulations

BACKYARD OFFICE REQUIREMENTS:

Permit Restrictions

• The decision on whether or not a Design Review is needed from the planning department depends on the zoning, square footage, floor area ratio of the existing house, and proposed lot coverage but will most likely be a staff-level decision

• Building permits are dependent on the type of structure and whether or not the space is conditioned

• The addition of electricity, a deck, or slab foundation (if needed) would all most likely trigger a building permit

Height and Setback Restrictions

ADU REQUIREMENTS:

Zoning Restrictions

• The following districts can build ADUs:

  • Single family residential: R-8, R-8.5, R-10, R-12, R-15, R-20, R-40

  • Duplex & multifamily: D-3, M-0.75, M-1, M-2, M-2.5, M-3

  • Other: M-H-D, H-P-D, M-U, O-S-R, HO P-D, P-D, SFH-PD1, MU-C, MU-R, MU-D

Setback and Height Restrictions

• Maximum height: 16 feet

• Setback Requirements:

  • Rear lot: 4 feet

  • Side lot: 4 feet

  • Any existing structure: 6 feet

Other Restrictions

• Owners may be required to sign something preventing them from doing

• The design of the ADU must be consistent with the architecture of the main house (including building form, exterior siding and/or trim, roof form and materials, and windows)

• Possible extra restrictions if:

  • the lot has an average slope of >15%

  • the lot is within 50 feet of a fault line or creek bed