Santa Clara County, CA Accessory Structures: Tiny Homes (2026)

Santa Clara County Ordinance NS-1200.371 amended the Zoning Ordinance in 2020 to recognize a Movable Tiny Home as a use classification distinct from a Standard ADU and a Junior ADU. Section 1.30.030 defines a movable tiny home as a detached structure on wheels used for dwelling purposes that provides complete independent living facilities for one or more persons and is located on the same lot as the primary dwelling. Section 4.10.015(B)(1) allows one ADU and one Junior ADU per legal lot, and Section 4.10.015(E) lets one movable tiny home substitute for the standard ADU. Specific tiny-home requirements in Section 4.10.015(E) include: (2) self-contained construction certified to ANSI 119.5 by an accredited third-party inspector, plus DMV licensing and registration; (3) shall not move under its own power; (4) shall be no larger than allowed by state law for movement on public highways; (5) at least 100 square feet of enclosed space; (6) direct connection to an approved water source, an onsite wastewater treatment system or sanitary sewer, and electric utilities (holding tanks may not be used for waste storage); (7) hidden undercarriage; (8) wheels and jacks on a Building Official-approved surface; (9) mechanical equipment incorporated into the original design (no rooftop or bolt-on add-ons); and (10) residential design (no shipping containers, no corrugated aluminum, no fiberglass siding; double-pane windows with exterior trim). Because Section 4.10.015(E)(1) ties tiny homes to the same setback, height, and floor area limits as standard detached ADUs in 4.10.015(D), a tiny home placed as an ADU may not exceed 1,200 square feet, must respect 4-foot side and rear setbacks, and is generally capped at 16 feet in height. California Government Code 65852.2 preempts most local restrictions on ADUs up to 800 square feet by right and limits county imposed standards. A separate state framework (AB 2533, 2024) prevents counties from outright banning movable tiny houses, and California Residential Code Appendix Q applies to tiny houses on a permanent foundation. The County applies these rules only in unincorporated areas; the 15 cities in Santa Clara County set their own ADU and tiny-home codes.