Expansion of Nonconforming Buildings in Concord

Nonconforming structures in Concord may generally be expanded or enlarged, provided the expansion complies with all current development code requirements and does not increase the degree of nonconformity. For nonresidential and multifamily structures, repair, maintenance, and improvements performed within a 12-month period exceeding 50 percent of the structure's value require a minor use permit approval.

Expansion of Nonconforming Structures

According to the Concord Development Code, a nonconforming structure may be expanded, enlarged, repaired, and maintained [Section 18.530.030(B)].

Expansion and Enlargement

Nonconforming structures may be enlarged or extended to occupy a greater area of land or building floor area, provided that any expansion or enlargement complies with all applicable requirements of the Concord Development Code and does not increase the degree of nonconformity [Section 18.530.030(B)(1)].

Repair, Maintenance, and Improvements

The rules for repairs and improvements depend on the type of structure:

Single-Family Dwellings or Duplexes: These structures may be maintained and repaired at the discretion of the owner [Section 18.530.030(B)(2)].
Multifamily and Nonresidential Structures: These structures may be maintained, repaired, and improved as outlined in the following table:

Work Type	Value/Cost Threshold	Permit Requirement
Repairs, Maintenance, and Improvements	Up to 50% of the value of the structure (within any 12-month period)	No permit specifically listed, excluding structural alterations
Repairs, Maintenance, and Improvements	Greater than 50% of the value of the structure (within any 12-month period)	Minor Use Permit

Seismic Retrofitting and Building/Fire Code Compliance

Repairs, alterations, or reconstruction necessary to reinforce unreinforced masonry structures to comply with the Concord Building Code and fire code requirements are allowed, provided the work is exclusively to comply with applicable earthquake safety standards and the building code [Section 18.530.030(B)(3)]. Costs associated with required foundation work are not counted toward the 50 percent valuation limitation [Section 18.530.030(B)(4)].

Loss of Nonconforming Status

Nonconforming status for a structure or physical improvement terminates if it is involuntarily damaged or destroyed by a calamity (such as fire, earthquake, or explosion) and the cost of repair or replacement exceeds 50 percent of the assessed value immediately prior to the damage [Section 18.530.040(B)]. In such cases, the structure must be reconstructed in conformity with the requirements of the applicable zoning district [Section 18.530.040(B)(2)].

Sections Cited