San Francisco Zoning Restrictions Rules (2026): What You Need to Know

San Francisco's regulatory approach to home-based businesses reflects the city's strong tradition of entrepreneurship and its recognition that many modern knowledge-economy workers operate from home. Planning Code Section 204.1 defines accessory uses in residential districts and provides the framework under which home occupations are permitted. A home occupation is an accessory use that must be clearly subordinate and incidental to the primary residential use of the dwelling unit. The key principle is that the residential character of the neighborhood must be preserved — neighbors should not be able to detect that a business is operating from the residence based on external appearances, traffic patterns, noise, or other impacts.

The business must be conducted entirely within the enclosed dwelling unit. Garages may be used for business activities only if the garage continues to provide any required residential parking. Detached accessory structures (such as backyard cottages or sheds) may be used for limited home occupation activities, but the primary business operations must occur within the main dwelling. No exterior storage of materials, equipment, or inventory is permitted, and no outdoor business operations may take place.

All businesses operating in San Francisco, including home-based businesses, must obtain a San Francisco Business Registration Certificate from the Office of the Treasurer and Tax Collector. The annual registration fee is based on the business's gross receipts and ranges from $50 for very small businesses to several hundred dollars for larger operations. Some small businesses with very low gross receipts may qualify for a small business exemption. Operating a business without a valid registration certificate is a violation subject to penalties. Additionally, depending on the nature of the business, other licenses or permits may be required — such as a seller's permit from the California Department of Tax and Fee Administration for businesses selling tangible goods.

San Francisco's home occupation regulations do not specify a precise maximum percentage of floor area that may be devoted to business use, but the general accessory use standard requires that the business remain clearly secondary to the residential use. In practice, a home office, studio, or workspace occupying one or two rooms of a dwelling is typical and acceptable. The business must not generate impacts — including noise, odor, vibration, electromagnetic interference, or hazardous emissions — beyond what is normal for a residential neighborhood. One non-resident employee working at the home premises is generally considered acceptable, but multiple non-resident employees whose arrivals and departures create noticeable traffic would likely exceed the accessory use threshold.

Prohibited home occupation activities include retail stores or showrooms open to walk-in customers, automobile or vehicle repair, welding or machining, commercial food preparation requiring a Health Department permit (though cottage food operations under the California Homemade Food Act have separate rules), medical or dental offices with regular patient visits, and any business involving the storage or use of hazardous materials. Contact the San Francisco Planning Department at (628) 652-7600 for zoning questions or the Office of the Treasurer and Tax Collector at (415) 554-4400 for business registration.