San Diego County opens unincorporated land to tiny home primary residences

Tiny Homes on Wheels can now qualify as legal dwellings in unincorporated San Diego County, expanding where they can serve as a primary residence. The new rules could broaden housing options, but buyers still have to clear zoning, utilities, septic, fire access and permit hurdles before a project moves forward.

Why it matters: - San Diego County’s rule change gives tiny home buyers a new path to homeownership on qualifying land in unincorporated areas. - The update could support smaller-footprint housing, multigenerational living and lower-cost ownership options. - The change does not make tiny homes legal on every parcel, so land review still determines whether a project is viable.

What happened: - The County of San Diego confirmed in September 2025 that qualifying Tiny Homes on Wheels can meet the definition of a dwelling under the County Zoning Ordinance. - The county formally announced the expanded housing option on Oct. 1, 2025. - Qualifying Tiny Homes on Wheels can now be permitted as legal dwellings in unincorporated San Diego County. - The homes may now serve as a primary residence on qualifying property instead of only as accessory housing behind an existing house.

The details: - Buyers still need to determine whether a parcel allows a tiny home based on zoning, allowable density and location. - Site review also has to account for septic or sewer capacity, water and utilities, fire access and safety, flood risk, grading and county permits. - The tiny home itself must meet certification and construction standards. - Financing for both the land and the home is part of the planning process. - Qualifying Tiny Homes on Wheels are generally limited to 430 square feet. - A permit is required before a tiny home can be legally installed and occupied as a residence. - Stephanie Sundell, known as the Tiny House Realtor, is helping buyers and property owners work through land selection, property review, builder connections and project planning. - Sundell combines real estate experience with tiny house development and ownership. - Sundell said buyers often want to live tiny but do not know where to start, and that the land, zoning, home, utilities, septic, financing and permits all have to work together.

Between the lines: - The county rule change opens the door, but the permitting and site-approval process still creates a high bar for buyers. - The new rules make early land due diligence more important because the wrong parcel could add cost before a buyer orders a home. - Specialized guidance is becoming more valuable as tiny homes move from niche lifestyle choice to regulated housing option.

What's next: - Buyers interested in tiny home living will likely need to verify parcel eligibility before purchasing land or ordering a home. - Property owners will need to evaluate whether their site can meet county standards for utilities, septic, access and permits. - Sundell says her goal is to help clients confirm whether the full plan works before they spend money in the wrong place. - For more information, contact Stephanie Sundell or visit her social profiles: LinkedIn, Instagram, Facebook, YouTube, and tinyhouseyosemite.lodgify.com.

The bottom line: - San Diego County’s tiny home rule change expands housing choices, but only buyers with qualifying land and a workable permit path can turn the option into a legal primary residence.