Tiny Home Clarity

San Diego tiny-house guide

Tiny Houses in San Diego: City or County?

The City of San Diego and unincorporated San Diego County have different official paths for a movable tiny house. Another incorporated city has its own rules. Confirm which government controls the parcel before buying land or a home.

Official sources checked: 2026-07-28

Choose your route

Which office controls the property?

A San Diego mailing address or search result does not establish the land-use jurisdiction. Use the parcel address or APN.

Inside the City of San Diego Use current City Municipal Code section 141.0318 and City Development Services. Unincorporated San Diego County Use the County THOW determination and County Planning & Development Services. Another incorporated city Stop. Neither summary below answers that city's placement or permit rules.

Not sure? Check the County's official unincorporated-area map, then save the result and confirm it with the responsible planning office.

Why the names change:

The City code calls its wheeled residential unit a Movable Tiny House (MTH). County guidance uses Tiny Home on Wheels (THOW). A seller's label does not place a unit into either path automatically, and a conventional ADU is a different construction path.

Two different paths

What changes between the City and County?

Both paths require a permit and parcel review. The possible use, unit standard, site filters, and responsible office are different.

City of San Diego only

Movable Tiny House under section 141.0318

Possible path: the current City code regulates a Movable Tiny House as a limited use in eligible zones. It is a separate code section, not blanket ADU permission.

Possible role
One Movable Tiny House per premises, in addition to ADUs and JADUs allowed under the separate ADU section.
Unit proof
DMV license and registration plus NFPA 1192 or ANSI A119.5 certification from a recognized national certification body.
Property filters
An eligible zone, primary-dwelling context, right-of-way access, side or rear placement, separation, fire, brush-management, habitat, parking, and coastal conditions may matter.
Utilities and use
Water, sewer, and electric connections are required; natural gas is prohibited. A rental term cannot be shorter than 30 consecutive days.
Ask City Development Services in writing

"Does section 141.0318 permit this exact Movable Tiny House on APN [number], and which zone, access, fire, coastal, utility, certification, and permit requirements apply?"

Current official starting points

Source confidence: High. The current City path is documented. Parcel, zone, unit, and permit eligibility are unverified.

Unincorporated San Diego County only

Tiny Home on Wheels under the County determination

Possible path: since September 4, 2025, County guidance says a qualifying THOW may be used as a primary or accessory dwelling when the County's standards and permit requirements are met.

Possible role
Primary or accessory dwelling, subject to the property's allowed building type, density, setbacks, and other zoning rules.
Unit proof
ANSI A119.5 design and certification by an approved third-party agency, plus County-specific construction and fire requirements.
Property filters
Legal lot status, fire access, wastewater, potable water, flood, grading, stormwater, right-of-way, paved support, separation, and inspections may matter.
Size and utilities
The County publishes a 430-square-foot cap, one story, and a 16-foot maximum height. Approved electric, potable-water, and wastewater systems are required. A sleeping loft may be up to 150 square feet.
Ask County PDS and Environmental Health in writing

"Is APN [number] in unincorporated County jurisdiction, and can this certified THOW be reviewed as a primary or accessory dwelling with the site's zoning, density, fire access, water, and wastewater conditions?"

Current official starting points

Source confidence: High. The current County path is documented. Parcel, density, water, wastewater, fire, unit, and permit eligibility are unverified.

If the parcel is in another incorporated city, stop here.

The County THOW determination does not control incorporated cities, and City of San Diego code does not control another city. Ask that city's planning or building office for the rule that applies to the exact unit and intended use.

Listings, builders, communities, and stays

What a search result does not prove

Broad San Diego searches mix products, services, land, communities, and vacation stays. Treat them as leads until the jurisdiction and written proof match your plan.

What you found What it may tell you What to get before paying
A THOW or movable tiny house for sale The product may have a label or certification. That does not prove it meets the selected jurisdiction's standards or fits the parcel. Certification standard and agency, dimensions, DMV status, construction details, utility design, warranty, delivery, setup, and correction responsibility.
A tiny-home or ADU builder quote The quote may describe a conventional ADU, MTH, THOW, park model, RV, kit, shell, or another product. Those paths are not interchangeable. Exact product category, jurisdiction assumed, plans and permits included, site work, utilities, delivery, inspections, taxes, exclusions, change orders, and refund terms.
Land, a community, or a lot lease The listing may show space or an existing use. It does not prove residential occupancy, a new permit, unit ownership, or transferable approval. APN, controlling jurisdiction, zoning response, allowed use and duration, unit rules, utility responsibility, lease terms, insurance, and written permit history.
A tiny-house rental or vacation stay It may help you experience the space. It does not establish long-term placement or rental permission for another property. Whether it is a short stay, long-term tenancy, lot lease, or owned unit, and which rules support that exact use at that location.

Before land, a deposit, or a contract

Build a written proof file

A confident sales answer is not a parcel or permit answer. Save the documents that let you compare the property, unit, and quote as one project.

  1. Save the parcel address, APN, and an official jurisdiction-map result.
  2. Write down whether the plan is a primary home, accessory home, long-term rental, lot lease, or short stay.
  3. Get the responsible office's written response on zone, density, use, access, fire, coastal, and permit path.
  4. Confirm potable water, wastewater, electric service, site work, delivery access, and inspections before assuming the parcel is buildable.
  5. Collect the unit's classification, certification label and agency, dimensions, DMV status, plans, and construction specifications.
  6. Make the seller or builder list every included and excluded item, including permits, engineering, delivery, setup, utilities, site work, taxes, corrections, and warranty.
  7. Assign responsibility for permit comments, failed inspections, redesign, change orders, schedule delays, and damage in writing.
  8. Do not make a nonrefundable payment until the property path, unit proof, and contract assumptions agree.

Continue the decision

Check placement and project cost together

Organize the jurisdiction, home type, use, and land checks Placement decision tool Compare a seller quote with the larger project budget Tiny Home Cost Calculator Stress-test what a low advertised number leaves out Under-$20K guide