Antioch, CA Historic Preservation: Historic-Cultural Monuments (2026)

3005's test for what counts as a legal nonconforming parcel. 3006(A) lists three conditions a historic structure must satisfy together: it must be 'Designated by the city as an historic site or structure as listed in the general plan'; it must separately be 'Designated as a California State Historic Landmark or a National Register Site'; and any alteration or enlargement must leave 'the entire structure' as 'an authentic replica of the original structure' once the work is done. Meeting all three lets an owner rebuild or expand a historic structure that would otherwise be frozen in place by the zoning code's general nonconformity rules, which normally bar increasing a nonconforming structure's footprint, height, or density without first bringing the whole property into compliance.

The section was adopted with the rest of Article 30 by Ordinance 2163-C-S, passed March 12, 2019, and it sits alongside a parallel rebuild right for damaged or destroyed nonconforming residential buildings in subsection (B), administered by the Director of Community Development, who reviews the applicant's supporting documentation. Antioch does not maintain a separate historic-preservation ordinance, a landmarks commission, or a cultural-monument registry in its municipal code; the general plan itself is the designation instrument, and the zoning code's role is limited to this narrow exemption once that designation already exists.