Data · 49 states and the District of Columbia
Tiny home building codes, state by state
There is no national building code in the United States. Codes are adopted state by state and enforced by local building departments, which is why the honest answer to “what code applies to my tiny home” starts with where you are putting it. Of the 50 guides we publish, a state-level residential code reaches a new home automatically in 35, applies only in part in 3, and is entirely a local decision in 12.
A code applying is not the same as a tiny home being allowed. Building codes govern how a home is built; zoning governs whether it may be placed and occupied on your lot, and zoning is local everywhere — including in the states with the strictest uniform codes. Guides that merge the two questions give the wrong answer to both.
Every row below is quoted from the state guide it links to, where the figure is cited to the state’s own authority. Free to cite or link with credit.
35
State code applies
3
Applies in part
12
Local choice
492
Primary sources cited
01 — How to read the scope column
- State code applies
- A state-level residential code reaches a new home automatically, even where enforcement is run locally. In some states that code is a minimum floor and a city may adopt a newer edition on top of it.
- Applies in part
- A state code exists but does not reach every home on its own: it covers only some jurisdictions, the edition in force is a local decision, or a local government can exempt itself.
- Local choice
- No state-level residential code applies on its own. Whether any code applies to your build, and which edition, is decided by your city or county.
The scope is our reading of each state’s own published position, not a separate legal opinion, and the code text beside it is the basis. Three states are commonly reported wrong on exactly this point: Tennessee has adopted the 2018 IRC, but counties and municipalities may exempt themselves by a two-thirds vote; Maine’s code binds municipalities of 4,000 or more; and Iowa maintains state codes while leaving the edition in force to local adoption.
02 — Building code by state
| State | Scope | Code in force | How a tiny home is classified |
|---|---|---|---|
| AlabamaAL | State code applies | A statewide residential code applies to new residential construction and substantial renovations. The operative baseline today is the 2015 IRC as modified (ADECA rule 305-2-4-.09); the code adopted through the new Home Builders Licensure Board process binds builders from 1 January 2027, and its edition has not been announced | Travel trailers and folding or collapsible camping trailers not more than 20 model years old require an Alabama certificate of title; utility trailers are exempt, as is any trailer more than 20 model years old. A home built to the residential code on a permanent foundation is a building, and the vehicle title requirement does not apply to it. |
| AlaskaAK | Local choice | No single statewide residential code enforced everywhere. Boroughs and municipalities adopt their own IRC/IBC versions with Alaska-specific amendments; state 2018 IRC Alaska-specific amendments took effect 1 Jan 2019 | Alaska DMV exempts manufactured homes and house trailers from registration, though titles are still required for them. Travel trailers and fifth wheels are registered like other vehicles, and a homebuilt trailer needs inspection, an assigned VIN, a homebuilt trailer affidavit and a weight slip before it can be titled and registered. |
| ArizonaAZ | Local choice | No statewide code for ordinary construction. Each city/county is its own AHJ. Phoenix is on the 2024 I-Codes with the 2023 NEC (effective Aug 2025), Pima County on the 2024 I-Codes with the 2023 NEC (effective Jan 2026), unincorporated Maricopa County still on the 2018 I-Codes with the 2017 NEC | Titled as a trailer/travel trailer (or RV/park model) by ADOT MVD; a foundation tiny house is regulated locally under adopted I-Codes |
| ArkansasAR | State code applies | 2021 IRC, adopted as the Arkansas Fire Prevention Code (Vol. III), effective Jan. 1, 2023, statewide; permitting and inspection handled locally | A factory tiny house on wheels is treated as an RV/trailer; a foundation-set unit is a modular home under the Arkansas Manufactured Home Commission. |
| CaliforniaCA | State code applies | California Building Standards Code (Title 24); 2025 edition (2025 CBC/CRC based on 2024 IBC/IRC) mandatory since January 1, 2026, administered locally | Movable: park trailer or travel trailer (DMV-registered vehicle). Permanent: foundation-built ADU or HCD Factory-Built Housing unit. |
| ColoradoCO | Local choice | No statewide general building code. Cities and counties adopt and enforce their own and issue permits locally; verified adoptions range from the 2015 I-Codes (Garfield County) to the 2024 I-Codes (Denver's 2025 code, Larimer County). Electrical is the exception: the State Electrical Board adopts the NEC statewide (2023 NEC since Aug 2023), and jurisdictions updating codes must meet at least 2021-IECC energy performance (HB22-1362). | On wheels: titled as a trailer/RV through the county DMV. Factory-built movable or modular: a state-regulated factory-built structure carrying a Colorado Division of Housing insignia. |
| ConnecticutCT | State code applies | 2022 Connecticut State Building Code applies statewide, with the residential portion based on the 2021 IRC | A tiny house on wheels is registered as a camp trailer through the DMV, with a title required where the GVWR is over 3,000 lbs and the trailer is newer than 20 years; homemade trailers must be inspected and assigned a VIN at a DMV safety inspection location. A home built to the state building code on a permanent foundation is a building. |
| DelawareDE | Local choice | No statewide residential code. Under 16 Del. C. 7601 the counties may adopt and enforce their own; New Castle is on the 2021 IRC (eff. 1 Jan 2024), Sussex on the 2021 IBC/IRC (eff. 1 Jan 2023), Kent on the 2018 IBC/IRC with county amendments | A tiny house on wheels is a titled vehicle (Delaware's code distinguishes manufactured homes from travel trailers, recreational vehicles, park trailers and camping trailers), while a foundation-built or manufactured home is installed as a building and can be treated as real property. |
| District of ColumbiaDC | State code applies | 2017 DC Construction Codes (DCMR Title 12), effective May 29, 2020, built on the 2015 ICC family (2015 IBC/IRC/IECC) with District amendments | A tiny home on wheels is titled as a trailer/RV by DC DMV, not a dwelling; a legal tiny home is a foundation or modular ADU under the DC Construction Codes. |
| FloridaFL | State code applies | 2023 Florida Building Code, 8th Edition (based on the 2021 IRC/IBC); one code statewide | THOW titled as an RV (Travel Trailer, or Park Trailer over 400 sq ft); foundation homes via the DBPR Manufactured Buildings Program insignia or FBC Appendix Q. |
| GeorgiaGA | State code applies | 2024 IBC and 2024 IRC with Georgia Amendments (2015 IECC for energy). Permitting and inspection are handled locally by each city or county. | On a foundation, a site or modular dwelling under the state codes (tiny houses 400 sq ft or less may use IRC Appendix Q where the local jurisdiction has adopted it); on wheels, an RV or travel trailer. |
| IdahoID | State code applies | 2018 IRC (Idaho Residential Code, 2020 ed.) and 2018 IBC statewide; structural loads per ASCE 7-16 | A tiny house on wheels is titled and registered only as a vehicle (a park model RV or a travel/camp trailer), not as real property. A foundation-built unit of 400 sq ft or less can be permitted as a dwelling under IRC Appendix Q. |
| IllinoisIL | State code applies | From 1 January 2025 every area in Illinois must implement a building code meeting minimum standards set by the International Code Council, under the Capital Development Board Act (20 ILCS 3105), including areas that previously had none | A home built to the locally implemented code on a permanent foundation is a dwelling under that code, which since 2025 must meet ICC minimum standards everywhere in Illinois. |
| IndianaIN | State code applies | The Indiana Residential Code applies statewide, adopting the International Residential Code by reference with Indiana amendments; the 2020 Indiana Residential Code is built on the 2018 IRC | A home built to the Indiana Residential Code on a permanent foundation is a dwelling under the statewide code. Local ordinances may add requirements but cannot reduce the state standard. |
| IowaIA | Applies in part | Iowa maintains state construction codes, with Des Moines and most metro communities on the 2024 IRC effective 1 January 2026; the edition in force elsewhere depends on local adoption | Modular factory-built structures and manufactured homes fall under Iowa's statewide factory-built structures programme, which covers manufacture, installation and the procedures governmental subdivisions follow. A home built to the adopted local code on a permanent foundation is a building under that jurisdiction's rules. |
| KansasKS | Local choice | No statewide building code; only the Kansas Fire Prevention Code is mandatory statewide. Cities and counties adopt their own; Wichita, Overland Park and Kansas City, KS are on the 2018 IRC with local amendments | A manufactured home carries a HUD label on every section and is titled; once permanently affixed to a foundation not removable intact from the property, the certificate of title can be eliminated and the county appraiser generally determines real property status. A modular home is a code-built structure transportable in sections. A tiny house on wheels remains a titled trailer. |
| KentuckyKY | State code applies | Kentucky Residential Code, statewide, uniform and mandatory (815 KAR 7:125, amended effective 3 December 2024): the 2018 Kentucky Residential Code, Third Edition (August 2024), on a 2015 IRC base with Kentucky amendments | A home built to the Kentucky Residential Code on a permanent foundation is a building governed by the statewide code. A tiny house on wheels is a titled vehicle. Confirm the registration route and any occupancy limits with your county, since zoning rather than the building code governs whether a unit on wheels can be lived in. |
| LouisianaLA | State code applies | Louisiana State Uniform Construction Code, mandatory statewide; the residential code runs on a 2021 IRC base with amendments for hurricane resistance, flood mitigation and seismic | Louisiana treats a mobile home as movable, and therefore taxed and titled like a vehicle, for as long as it can be transported and remains registered as one. Converting it to immovable property runs through an act of immobilization. A home built to the state construction code on a permanent foundation is a building. |
| MaineME | Applies in part | The Maine Uniform Building and Energy Code applies to all municipalities with a population of 4,000 or more; permit applications from 7 April 2025 comply with the 2021 ICC codes as amended by MUBEC | A home built to MUBEC on a permanent foundation is a building under the state code. A trailer requires a title where its unladen weight is 3,001 lbs or more, and from 1 January 2026 vehicles of model year 2001 or newer must be titled; registration requires a signed bill of sale and, for newer heavier trailers, a title signed over to the new owner. |
| MarylandMD | State code applies | Maryland Building Performance Standards require every jurisdiction to use the same edition of the same I-codes. The state has adopted the 2021 IBC, IRC, IECC, IgCC and IEBC, with some jurisdictions transitioning to the 2024 editions | A modular home is built to residential code, carries green state certification labels inside the home, and is not designed to be moved once set on a permanent foundation. A manufactured (mobile) home is built to the federal HUD standard. A trailer is registered as a Class G vehicle under the transportation code. |
| MassachusettsMA | State code applies | 780 CMR 10th Edition statewide, effective 11 Oct 2024 (9th Edition concurrency ended 30 Jun 2025); Chapter 51 is the Massachusetts Residential Code, adopting the 2021 IRC with state amendments | A tiny house on wheels is registered as a trailer through the Registry of Motor Vehicles, so it is a vehicle and not real property; a modular tiny house or ADU on a permanent foundation is a building under 780 CMR and the state manufactured buildings program. |
| MichiganMI | State code applies | The Michigan Residential Code. Rule R 408.30500 adopts the 2015 edition of the International Residential Code with appendices A, B, C, D, E, F, G, J, K, N, O, P, R and S. The 2021 replacement was filed for 29 August 2025 but is paused by a Michigan Court of Claims order of 7 July 2025, so the 2015 edition governs | A home built to the Michigan Residential Code on a permanent foundation is a building, permitted and inspected by whichever agency enforces the code where you are. A factory-built unit can instead arrive as a premanufactured unit carrying a state certificate of acceptability under MCL 125.1519. A unit on a trailer chassis is vehicle territory: MCL 257.216 exempts trailers under 2,500 pounds empty weight from titling, so a heavier one needs a certificate of title from the Secretary of State. |
| MinnesotaMN | State code applies | Mandatory statewide. The 2020 Minnesota Residential Code is based on the 2018 International Residential Code and administered by the Department of Labor and Industry | A home built to the Minnesota Residential Code on a permanent foundation is a dwelling under the statewide code, held to an identical standard in every jurisdiction. |
| MississippiMS | Local choice | Mississippi Residential Code (2024 edition, 2021 IRC base, effective 1 Jul 2024), but adopted as a discretionary minimum; counties and cities choose whether to adopt, amend or enforce it | A mobile or manufactured home is issued a certificate of title like any other motor vehicle; once affixed to a permanent foundation the county Tax Assessor can classify it as real property, though that certificate is expressly for ad valorem tax purposes. A modular home falls under the state's licensed modular programme. |
| MissouriMO | Local choice | No statewide building code for private residential construction; cities and counties adopt and enforce their own, with Kansas City and St. Louis maintaining their own IBC and IRC amendments | Manufactured homes and modular units both fall under Public Service Commission oversight for manufacture, dealing and initial installation, with modular units built to the 2021 I-codes. A home built to a local jurisdiction's adopted code on a permanent foundation is a building under that jurisdiction's rules. |
| MontanaMT | State code applies | 2021 I-Code series statewide (IBC, IRC, IMC, IFGC, IECC), effective June 11, 2022; IRC Appendix Q adopted for tiny houses 400 sq ft or less | A THOW is titled as a travel trailer (a vehicle/RV); a modular tiny house on a permanent foundation is a factory-built building under the state insignia program. |
| NebraskaNE | State code applies | Neb. Rev. Stat. 71-6403 creates the state building code, adopting the 2018 IBC, IRC and IEBC by reference; under 71-6404 it applies automatically where no conforming local code exists, and under 71-6406 local codes must conform generally with it (prior editions do not conform) | Modular housing units produced or sold in Nebraska fall under Public Service Commission oversight, with approval granted at manufacturer level after document review and factory inspection. A site-built home is governed by your local code where a conforming one has been adopted, and by the state building code where none has. |
| NevadaNV | Local choice | No single statewide residential code. The State Fire Marshal sets baseline fire and building safety standards; residential permits are issued and enforced by local city and county building departments | A home built to the county's adopted residential code on a permanent foundation is a building, permitted and inspected by that city or county building department. |
| New HampshireNH | State code applies | The New Hampshire State Building Code (RSA 155-A) adopts the 2021 IRC and 2021 IBC by reference, effective 1 July 2024, including amendments reviewed by the state building code review board and ratified by the legislature | A home built to the state building code on a permanent foundation is a building. Under the ADU statute one accessory dwelling unit, attached or detached, is allowed as a matter of right on a qualifying single-family lot. |
| New JerseyNJ | State code applies | The New Jersey Uniform Construction Code is adopted by regulation and administered by the Department of Community Affairs, Division of Codes and Standards | A home built to the UCC residential subcode on a permanent foundation is a dwelling under the statewide code, held to the same standard in every municipality. |
| New MexicoNM | State code applies | The New Mexico Residential Code adopts the 2021 IRC with state amendments under 14.7.3 NMAC, applied statewide | A home built to the New Mexico Residential Code on a permanent foundation is a building, permitted and inspected by the Construction Industries Division or your local enforcement agency. Earthen construction has its own code path under the Earthen Building Materials Code. |
| New YorkNY | State code applies | 2025 Uniform Code (effective Dec 31, 2025), based on the 2021 IRC and 2024 IBC with NY amendments; references ASCE 7-22 | On wheels, titled or registered as a trailer by the NY DMV; a factory-built modular unit is regulated under the state modular program and carries the DOS Insignia of Approval. |
| North CarolinaNC | State code applies | Mandatory statewide code enforcement under the North Carolina State Building Code; the 2024 edition took effect 1 July 2025 following a legislative delay to the original date | A home built to the North Carolina Residential Code on a permanent foundation is a dwelling under the statewide code, with enforcement mandatory across the state. |
| North DakotaND | State code applies | The North Dakota State Building Code's 2026 edition adopts the 2024 I-Code family, effective 1 January 2026; the prior 2023 edition was based on the 2021 I-Codes | A home built to the adopted state code on a permanent foundation is a building, permitted and inspected by the local jurisdiction where one maintains a building inspection department. |
| OhioOH | State code applies | The Residential Code of Ohio governs one-, two- and three-family dwellings and sits in the Ohio Administrative Code at 4101:8; it uses the 2018 International Residential Code as its basis | A home built to the Residential Code of Ohio on a permanent foundation is a dwelling under the state code, which covers one-, two- and three-family buildings. Manufactured homes fall under a separate state framework administered through Ohio's manufactured homes rules. |
| OklahomaOK | State code applies | The Oklahoma Uniform Building Code Commission adopts the statewide minimum codes; the 2024 editions of the IRC, IBC, IEBC, IFC, IFGC, IMC and IPC with amendments took effect 14 September 2026 | A home built to the adopted Oklahoma minimum codes on a permanent foundation is a dwelling under those codes, permitted and inspected by the local jurisdiction. |
| OregonOR | State code applies | 2023 Oregon Residential Specialty Code (based on the 2021 IRC), with IRC Appendix Q tiny-house provisions applied statewide; codes administered by the Oregon Building Codes Division, permits and inspections run locally | A tiny house on wheels is titled by the DMV as a recreational vehicle (travel trailer or park model); a foundation-set unit is regulated as a dwelling or ADU under the statewide building code. |
| PennsylvaniaPA | State code applies | The Uniform Construction Code is adopted statewide and applies to every new home. It moved to the 2021 ICC code series with Pennsylvania amendments effective 1 January 2026, applying to permits applied for on or after that date | A home built to the Uniform Construction Code on a permanent foundation is a dwelling under the statewide code, wherever in Pennsylvania it sits. Who enforces the code varies; whether it applies does not. |
| Rhode IslandRI | State code applies | The Rhode Island one- and two-family dwelling code (RISBC-2) adopts the 2018 International Residential Code together with Rhode Island amendments, applied statewide | A home built to the Rhode Island one- and two-family dwelling code on a permanent foundation is a building. Whether it can be an accessory dwelling depends on which of the 2024 law's three routes applies to your property. |
| South CarolinaSC | State code applies | Mandatory statewide. State law requires all municipalities and counties to enforce the codes adopted by the South Carolina Building Codes Council, within the Department of Labor, Licensing and Regulation | A home built to the state-adopted residential code on a permanent foundation is a dwelling, held to the same standard in every county and municipality in South Carolina. |
| South DakotaSD | Local choice | No statewide residential or energy code. Municipalities may adopt one; where a local government adopts standards for new construction, state law requires them to comply with the 2021 IBC | A HUD-code manufactured home is titled and registered through the state and carries an initial registration fee based on purchase price including installation; a modular home built to building-code standards is not titled or registered as a vehicle; a tiny house on wheels must be titled before it can be registered. |
| TennesseeTN | Applies in part | Tennessee has adopted the 2018 International Residential Code and the 2018 International Energy Conservation Code | A home built to the adopted residential code on a permanent foundation is a dwelling. Whether the state residential code applies at all depends on your county or municipality's status: covered, exempted or opt-out. |
| TexasTX | State code applies | Statewide statutory minimum is the 2012 IRC (2012 IBC for commercial/multifamily) via HB 738, effective Jan 1, 2022, with the 2015 IECC for energy. This is a floor; cities and counties permit locally and many adopt newer editions (2018/2021 IRC) plus local amendments. | A tiny house on wheels is titled as a trailer or travel trailer by TxDMV; a factory-built modular unit under the TDLR IHB program is treated as site-built real property. |
| UtahUT | State code applies | Utah Code 15A-2-103 (since 1 July 2026) lists the 2024 IBC, IPC, IMC, IFGC, IECC and IEBC with the 2023 NEC, while the residential code remains the 2021 IRC including Appendix AQ, with statewide amendments in Chapter 3 | A home built to the Utah residential provisions on a permanent foundation is a dwelling under the statewide construction code, subject to the state amendments as well as the model code. |
| VermontVT | Local choice | No statewide construction code for owner-occupied single-family homes; the Vermont Fire and Building Safety Code applies to public buildings, which excludes owner-occupied single-family residences | A tiny house on wheels follows the trailer path: Vermont does not title trailers under 1,500 lbs empty weight, while heavier trailers and camper trailers are titled and registered, and registered vehicles are subject to annual safety inspection. A foundation-built home is a building, and whether a construction code applies depends on whether it is owner-occupied or rented. |
| VirginiaVA | State code applies | Virginia Uniform Statewide Building Code, adopted and amended by the Board of Housing and Community Development from nationally accepted model codes with minimal modification; enforcement is the responsibility of the local building inspections department | A home of 400 sq ft or less built under Appendix Q of the Virginia Residential Code is a dwelling with a documented compliance path. A tiny house on wheels is a titled trailer through the DMV, registered annually, biennially or permanently with the fee based on gross weight, and new residents have 30 days to title and register. |
| WashingtonWA | State code applies | 2021 I-Codes (2021 IRC/IBC with Washington amendments), effective statewide March 15, 2024; permits enforced by local city and county building departments | L&I gold-insignia "Tiny House" (a building, not vehicle-titled) if ≤400 sq ft and built to the WA State Building Code; otherwise an RV or park model RV titled through DOL |
| West VirginiaWV | Local choice | West Virginia State Building Code (87 CSR 4) is built on the 2018 IBC and 2018 IRC with state amendments, but has force only in counties and municipalities that adopt it | A tiny house on wheels is registered through the West Virginia DMV as a trailer, so it is a vehicle and not real property; a factory-built or modular home is titled and can be converted to real property by deed once permanently affixed to land. |
| WisconsinWI | State code applies | Wisconsin Uniform Dwelling Code (SPS 320-325), mandatory statewide for new one- and two-family dwellings since 1 June 1980; the code is Wisconsin's own rather than a direct IRC adoption, though it borrows IRC design tables and the simplified wall-bracing method | The Uniform Dwelling Code covers site-built dwellings, manufactured buildings used as dwellings, and modular homes, with separate provisions for HUD homes built under federal regulations. Licensed manufactured home installers are responsible for compliance with the installation requirements in SPS 321. A tiny house on wheels is titled and registered as a trailer through the Department of Transportation. |
| WyomingWY | Local choice | The State Fire Marshal's statewide adoptions (as of 28 June 2024) are the 2024 IBC, IFC, IMC, IFGC and IEBC plus the NEC, applying to public, business and industrial buildings under W.S. 35-9-107; the IRC is not state-adopted | A modular home built to the adopted residential code and set on a permanent foundation is a building. A tiny house on wheels remains a titled vehicle. Confirm the registration route and any occupancy limits with your county: Wyoming handles vehicle titling through county offices, and local zoning governs whether a unit on wheels can be lived in. |
We do not publish a guide for Hawaii, so it is not in this table. We would rather leave a gap than fill it with research we have not done. Codes change. Each state guide carries the date and the sources behind its figures; if you find one stale, tell us and we will correct it.
03 — What this table does not tell you
Whether you can put one on your lot. That is zoning, and it is decided by your city or county, not by the code column. Two parcels under the same state code can answer differently.
What your local amendments say. Where a state code is a minimum floor, a city may adopt a newer edition and add to it. The row tells you the floor.
Whether Appendix Q applies. Appendix Q adoption is separate from adopting the IRC itself and is often permissive even where a state has adopted it. Where a state guide verified the Appendix Q position, it says so on that page.
Septic, water and utility rules. We have not researched those state by state, so we do not publish them. Your building department and health authority are the answer.
04 — Common questions
- Are tiny homes legal in every US state?
- There is no national yes or no, because there is no national rule to answer it. Building codes are adopted state by state and enforced by local city and county building departments, so legality is a question about your jurisdiction rather than your state. Most states have a workable path for at least one type of small home; what differs is which type, and under what conditions.
- Does a statewide building code mean a tiny home is allowed?
- No, and conflating the two is the most common error in tiny home code guides. A building code governs how a home is built: structure, egress, energy, plumbing. Zoning governs whether a dwelling of that type may be placed and occupied on your parcel, and zoning is local everywhere, including in states with a strict uniform code. A home can be fully code-compliant and still not permitted on a given lot.
- Which states have no statewide residential building code?
- By our count of the 50 guides we publish, 12 have no state-level residential code that reaches a new home on its own: Alaska, Arizona, Colorado, Delaware, Kansas, Mississippi, Missouri, Nevada, South Dakota, Vermont, West Virginia, Wyoming. In those places whether any code applies, and which edition, is decided by your city or county. A further 3 apply only in part.
- What is IRC Appendix Q?
- Appendix Q is the part of the International Residential Code written for tiny houses under 400 square feet. It adjusts requirements that a full-size code makes impractical at that scale, covering stairs, ladders, headroom and lofts, so a small home can be permitted as a real dwelling. It is adopted jurisdiction by jurisdiction rather than nationally, so a home built to it is not automatically permittable everywhere.
Know the code. Now check the lot.
The code is the easy half. We check your destination before you sign anything, and say so plainly if it does not work.