Colusa County, CA Home Business: Zoning Restrictions (2026)

Colusa County treats home-based businesses as "home occupations," governed by Section 44-4.90 of the Zoning Code's Special Use Provisions. The code states that "home occupations shall be permitted as appurtenant and accessory uses to any residential uses," so they are broadly allowed across residential zones in the unincorporated county rather than confined to a special district. The defining standards keep the use residential in character: the home occupation must be confined completely within a legal structure and occupy not more than twenty-five percent of the floor space of a dwelling, or fifty percent of an accessory building. It must produce no evidence of its existence upon or beyond the premises, such as external alteration creating a nonresidential or unsightly appearance, noise, smoke, odors, or vibrations. The use must be carried on by members of the family occupying the dwelling, with no other persons employed, and any merchandise sold must be produced on the premises or be directly related and incidental to the service offered. One sign is allowed as permitted by the Sign Regulations (Section 44-3.50). These limits ensure home businesses blend into the surrounding residential and rural neighborhoods. An administrative permit must be obtained before the use begins.