Guidelines for Use and Permitting of Accessory Dwelling Unit – Movable Tiny House (LADBS Information Bulletin P/ZC 2023-021)

Can You Put a Tiny House on Wheels in Your L.A. Backyard? The MTH Permit, Explained If you've shopped for a backyard ADU, you've probably seen "tiny homes o...

Written by 1-800-ADU-Pros

Last updated: July 16, 2026•9 min read

Guidelines for Use and Permitting of Accessory Dwelling Unit – Movable Tiny House (LADBS Information Bulletin P/ZC 2023-021)

Can You Put a Tiny House on Wheels in Your L.A. Backyard? The MTH Permit, Explained

If you've shopped for a backyard ADU, you've probably seen "tiny homes on wheels" that cost a fraction of a site-built unit. Good news: Los Angeles has a dedicated, fast-track path for exactly this — the Movable Tiny House (MTH) as an ADU. The rules live in one LADBS document: Information Bulletin P/ZC 2023-021, Guidelines for Use and Permitting of Accessory Dwelling Unit – Movable Tiny House. (Heads up: the City still hosts the file under its old "2020-021" name, but the live version is 2023-021.)

Here's what a homeowner actually needs to know.

What counts as a "Movable Tiny House"

This path is narrow and specific. To qualify, your unit must be ALL of the following:

Licensed and registered with the California DMV
Certified to ANSI A119.5 or NFPA 1192 by an approved third-party agency
Unable to move under its own power (no engine)
Road-legal in size
Between 150 and 430 square feet (measured inside the exterior walls)

If your unit is site-built on a foundation, smaller than 150 sf, larger than 430 sf, or a HUD manufactured home, you're on the standard ADU path instead — not this one.

The big surprise: no building permit

Because L.A. doesn't treat an MTH as a "structure," you do NOT pull a building permit. Instead you get a Use of Land permit combined with Electrical and Plumbing permits. That also means building-code and fire-sprinkler requirements don't apply. It's a genuinely lighter process — but the design rules below still bite.

Design and placement rules

LADBS wants the unit to look like a house, not a trailer:

Roof: minimum 12:2 pitch over more than half the roof; no wood shingles
Siding: no single-piece composite, laminates, or interlocked metal sheathing
Windows/doors: double-pane, labeled for building use, with exterior trim and no radius (rounded) corners
Undercarriage: wheels, axles, tongue, and hitch must be hidden from view
No slide-outs, tip-outs, or roof-mounted mechanical equipment
Wheels and jacks must sit on a paved surface

Placement: outside the front-yard setback, at least 4 feet from rear and side lot lines, and not between your house and the street. Only one MTH per lot, and only one approved per lot every 12 months. Utilities: connect to water, sewer, and electric, with a 30-amp minimum circuit. One parking space is required unless you're near transit, a car-share spot, or in a historic district.

How to file

Confirm eligibility — residential lot with a primary dwelling, not blocked by Very High Fire Hazard or Hillside limits, and a certified, DMV-registered, correctly sized unit.
Pull permit history — copies of all existing permits and plot plans from the LADBS Records Section.
Draw the Plot/Site Plan — 24"x36", to scale, showing the MTH footprint, roof slope, setbacks, parking, driveway, utility hookup post, and easements.
Get Sewer Availability clearance from Public Works – Bureau of Engineering.
Notarize the Owner's Acknowledgement & Declaration (page 5 of the bulletin) — signature must be notarized.
Apply at LADBS for the Use of Land + Electrical + Plumbing permit, with your plans, certification, DMV registration, records, and notarized form.
Clear any other agency reviews (Housing Department, LADWP) if requested.
Install and pass inspections, then receive your Certificate of Occupancy.

Fees and timeline

The Certificate of Occupancy for use of land is a flat $150. The combined Electrical/Plumbing inspection fee is calculated per the LADBS fee table and depends on the work. Separately, budget for third-party ANSI/NFPA certification (often handled by the manufacturer), sewer clearance, and notary fees.

Because this is a ministerial approval, California ADU law gives the City 60 days to act on a complete application — and as of January 1, 2026, SB 543 requires the City to confirm your application is complete within 15 business days. In reality, the longest stretch is getting your unit certified and your plans drawn; once you submit a complete package, the City's clock is short.

Don't trip on these

The most common ways homeowners get stuck: buying an uncertified "tiny home," guessing on the 150–430 sf range, leaving the hitch exposed, submitting an un-notarized declaration, forgetting the sewer clearance, or assuming they need a building permit. Get the certification and the plan set right, and the MTH path is one of the cleaner ADU options in the city.

This is general guidance, not legal advice. Always confirm current requirements and fees with LADBS before you file.

Reference card

Official number: P/ZC 2023-021 (previously issued as P/ZC 2020-021); Reference: LAMC 12.22 A.33 & Gov. Code §65852.2. Effective 01-01-2023, revised 12-20-2022.
Issuing body: Los Angeles Department of Building and Safety (LADBS), Building Code / Zoning (Plan Check). Sewer clearance via City of Los Angeles Public Works – Bureau of Engineering; MTH certification via HCD-approved third-party agencies.
What it is: An LADBS Information Bulletin (a "how-to" guidance document, not itself an application form) that explains the City of Los Angeles's rules for using a Movable Tiny House (MTH) as an Accessory Dwelling Unit under LAMC 12.22 A.33. It is the City's single controlling reference for the MTH path: it defines what legally counts as an MTH, lists the zoning, design, and utility standards an MTH must meet, and spells out exactly which permits LADBS requires (a Use of Land permit combined with Electrical and Plumbing — notably NOT a building permit, because the City does not treat an MTH as a "structure"). Importantly, the bulletin was renumbered: the operative version is P/ZC 2023-021, which supersedes the older 2020-021 number, though the file is still hosted under the 2020-021 filename.
Who needs it: Applies to any L.A. homeowner who wants to place a factory-built, road-legal movable tiny house on wheels and use it as an ADU. It is the right path ONLY if the unit is DMV-registered, cannot self-propel, is certified to ANSI A119.5 or NFPA 1192 by an approved third-party agency, and is 150–430 sq ft. You should NOT use this path (and instead build a conventional/standard ADU under LAMC 12.22 A.33) if your unit is a site-built or panelized structure on a permanent foundation, is under 150 or over 430 sq ft, or is an HUD-code manufactured home — those follow the standard ADU building-permit process, not the MTH Use of Land process. The MTH path is also restricted/limited in Very High Fire Hazard Severity Zones and Hillside Areas (per LAMC 12.22 A.33(c)(4)). Only one MTH is allowed per lot, and only one may be approved per lot in any 12-month period.
Fees: Certificate of Occupancy for use of land: $150.00 flat (per LABC Section 107.2.7). Combined Electrical and Plumbing inspection fee: variable, calculated per LABC Section 107.2.2 / Table 1-A.1 (depends on the work). No building-permit plan-check fee applies because no building permit is issued. Budget separately for third-party ANSI/NFPA certification (paid to the inspection agency / often handled by the manufacturer) and Bureau of Engineering sewer clearance and notary fees. Fee figures are from the bulletin; confirm current amounts with LADBS at intake.
Timeline: The bulletin states no processing time. Because MTH approval is ministerial, California ADU law (Gov. Code §65852.2, recodified in the §66310+ series) controls: the City must act on a complete ADU application within 60 days. As of January 1, 2026, SB 543 also requires the agency to determine completeness and give written notice within 15 business days (the application is deemed complete if it misses that). Most of the real-world time goes to getting the unit's third-party ANSI/NFPA certification and the plan set ready; once a complete package is submitted, plan on roughly a 60-day ministerial window plus inspection scheduling.

Requirements

Proof the MTH is licensed and registered with the California DMV
Third-party certification (from an HCD-approved Design Approval Agency / Quality Assurance Agency) that the unit meets ANSI A119.5 or NFPA 1192
Unit sized 150-430 sq ft (measured within exterior wall faces), max 2 stories, no slide-outs/tip-outs/articulating extensions
Site/Plot Plan, 24"x36", drawn to scale, fully dimensioned: vicinity map + north arrow; address, legal description, owner name/address/phone; lot dimensions, property lines, streets/alleys, existing buildings and use; parking layout, driveway, sidewalks; MTH footprint with dimensions, square footage, stories, roof slope; all distances to property lines and adjacent structures; location of utility hookups (post), existing visible utilities and easements
Permit History Records: copies of all existing building permits and plot plans for every structure on the lot (obtain from LADBS Records Section)
Sewer Availability clearance from Public Works – Bureau of Engineering
Possible review/approval from other agencies (Housing Department, LADWP)
Connection to water, sewer, and electric utilities; a 30-amp minimum circuit (or more if the manufacturer requires)
Compliant design: cladding/trim excluding single-piece composite, laminates, or interlocked metal sheathing; double-pane windows labeled for building use with exterior trim and no radius corners on windows/doors; roof min 12:2 pitch over >50% of roof area, no wood shingles; mechanical equipment built into the unit (not roof-mounted); undercarriage (wheels, axles, tongue, hitch) hidden from view; wheels/jacks on a paved surface per LAMC 12.21 A.6(c)
Setbacks: outside the required front-yard setback and at least 4 ft from rear and side lot lines; not placed between the primary dwelling and the fronting street (except qualifying Through Lots)
Parking: one standard space (waived if within 1/2 mile of bus/rail, within one block of a car-share location, or in a historic district/HPOZ)
Completed, signed, and NOTARIZED Owner's Acknowledgement & Declaration form (attached to the bulletin) listing all 17 provisions

How to file

1. Confirm eligibility: verify your lot allows residential use and has (or will have) a primary dwelling, and that you are not blocked by Very High Fire Hazard Severity Zone / Hillside limits. Confirm your unit is DMV-registered, road-legal, 150-430 sq ft, and ANSI A119.5 / NFPA 1192 certified by an HCD-approved third-party agency.
1. Pull your records: order copies of all existing building permits and plot plans for the lot from the LADBS Records Section.
1. Prepare the plan set: have a 24"x36" scaled, dimensioned Plot/Site Plan drawn showing everything in the bulletin's submittal list (footprint, roof slope, setbacks, parking, utility hookup post, easements).
1. Get your Sewer Availability clearance from Public Works – Bureau of Engineering before or alongside submittal.
1. Complete and notarize the Owner's Acknowledgement & Declaration form (page 5 of the bulletin).
1. Apply at LADBS for a Use of Land permit COMBINED with Electrical and Plumbing permits (no building permit is issued). Submit the plan set, certification, DMV registration, records, sewer clearance, and notarized declaration. This is a ministerial review.
1. Clear any inter-agency reviews (Housing Department, LADWP) if requested.
1. Install per the approved plans: connect water/sewer/electric (30-amp minimum), hide the undercarriage, set wheels/jacks on the paved surface, and pass Electrical and Plumbing inspections.
1. Receive your Certificate of Occupancy for the use of land. Note: if the MTH is built alongside a NEW primary dwelling, the MTH cannot be occupied or receive its C of O until the primary dwelling's C of O is issued.

Common pitfalls

Assuming you need a building permit — you do not. The MTH is permitted via a Use of Land permit (with Electrical/Plumbing); LADBS does not treat an MTH as a 'structure,' so building-code and fire-sprinkler provisions don't apply.
Buying an uncertified 'tiny home' — a unit that isn't DMV-registered AND ANSI A119.5 / NFPA 1192 certified by an approved third-party agency cannot qualify, no matter how nice it looks.
Wrong size — anything under 150 or over 430 sq ft (measured inside the exterior walls) is disqualified from the MTH path.
RV-style features that violate the design rules: slide-outs/tip-outs, radius-corner windows or doors, roof-mounted A/C, exposed wheels/hitch, single-piece composite or interlocked metal siding, or a roof flatter than 12:2 over more than half its area.
Skipping the notarized Owner's Acknowledgement & Declaration — it must be signed AND notarized and becomes part of the permit; an un-notarized form will stall you.
Forgetting the Sewer Availability clearance from the Bureau of Engineering, which is a separate prerequisite from the LADBS permit.
Setting the wheels/jacks on dirt or gravel — they must sit on a paved surface per LAMC 12.21 A.6(c).
Trying to occupy an MTH before the new primary dwelling's Certificate of Occupancy is issued when both are built together.
Citing the old number (2020-021) as the live rule — the current operative bulletin is P/ZC 2023-021 even though the City still hosts it under the 2020-021 filename.
Placing the MTH between the house and the street, or inside the front-yard setback / closer than 4 ft to a rear or side line.

Sources

Explore more:Permits & Feasibility

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