Residential building codes by state
Some states apply one residential code everywhere; others let each county decide. That single difference shapes inspections, financing and what you can build on rural land.
What to know first
Residential building codes reach a parcel in one of three ways. A statewide code applies everywhere, usually enforced by the state or by local building departments. A statewide code with local enforcement sets one standard but depends on cities and counties to inspect, and some rural areas may have no inspector. Under local adoption, each county or city chooses whether to adopt a code at all.
Our research found 6 states with a statewide code, 26 where a statewide code is enforced locally, and 18 where adoption is mainly local or limited. These categories simplify real differences, such as exemptions for agricultural buildings, minimum population thresholds and separate state electrical or plumbing codes. Read the summary and source for your state.
“No code” rarely means “no permits”. Septic, well, electrical, floodplain and zoning approvals usually still apply, and an uninspected home can be harder to finance, insure and sell. Our building guide explains how to sequence approvals and inspections, and the dwelling types guide covers how codes classify tiny homes, manufactured homes and RVs.
State-by-state table
Filter by status or search for a state. Each summary links to the official source we relied on, and each state name opens the full guide. Statuses describe state-level rules; counties, cities and health districts can add requirements.
50 states
| Alabama | Local adoption | The Alabama Energy and Residential Codes Board adopts residential and energy codes that later local codes may not conflict with. Permits and inspections depend on whether the city or county administers a code.Act 2010-185 (SB315, enrolled): Alabama Energy and Residential Codes Board Source |
|---|---|---|
| Alaska | Limited or none statewide | State Fire Marshal plan review exempts homes of three units or fewer. Residential codes are applied where a borough or city adopts them, so many rural areas have no residential building inspection.Alaska Department of Public Safety: State Fire Marshal Plan Review Source |
| Arizona | Local adoption | No statewide residential code applies. Counties with zoning may adopt building codes for unincorporated areas and may exempt areas zoned rural or unclassified. County building permits are still required by statute.A.R.S. § 11-861 (Adoption of codes by reference) Source |
| Arkansas | Statewide code, local enforcement | The State Fire Marshal maintains the statewide Arkansas Fire Prevention Code, and a residential energy code is mandatory statewide. Inspection depends on local jurisdictions, and rural enforcement varies.Arkansas Department of Public Safety: State Fire Marshal's Office Source |
| California | Statewide code, local enforcement | The California Building Standards Code (Title 24) applies statewide, and a permit from the local building official is required before building. Rural location does not create a general permit exemption.Contractors State License Board: Building Permit Requirements Source |
| Colorado | Local adoption | Colorado is a home-rule state with no statewide residential building code; counties and cities adopt and enforce codes. State plumbing code applies where no local code exists.US DOE Building Energy Codes Program: Colorado Source |
| Connecticut | Statewide code, local enforcement | The 2022 Connecticut State Building Code, based on the 2021 International Codes including the IRC, applies statewide to permit applications filed from October 1, 2022. Municipal building officials issue permits.Connecticut State Building Code — Regulations (Department of Administrative Services) Source |
| Delaware | Local adoption | Kent, New Castle and Sussex counties and municipalities adopt and enforce their own building codes. State law requires local codes to meet the current IECC and, from December 31, 2025, zero-net-energy-capable new homes.Title 16 Chapter 76 — Building Codes (Delaware Code Online) Source |
| Florida | Statewide code, local enforcement | The Florida Building Code applies statewide and covers wind, flood, energy and trades. Local building departments issue permits and inspect; confirm the edition in effect when your permit application is filed.Florida Building Code — Florida Building Commission Source |
| Georgia | Statewide code, local enforcement | Georgia's state minimum codes, including the 2024 International Residential Code with Georgia amendments, are mandatory. Counties and cities administer permits and inspections, and enforcement arrangements differ by jurisdiction.Current State Minimum Codes for Construction — Georgia Department of Community Affairs Source |
| Hawaiʻi | Statewide code, local enforcement | The State Building Code Council adopts a state building code based on national model codes, including the International Building Code and Uniform Plumbing Code. County building departments amend, permit and inspect locally.State Building Code Council — Hawaii Department of Accounting and General Services Source |
| Idaho | Statewide code, local enforcement | Idaho adopts the 2018 IRC with amendments as the Idaho Residential Code. The Building Code Act allows state or local enforcement; who issues permits, if anyone, depends on the jurisdiction.Idaho Adopted Codes (Division of Occupational and Professional Licenses, 2025) Source |
| Illinois | Statewide code, local enforcement | Since January 1, 2025, Public Act 103-0510 sets IRC-based baseline structural codes. Local governments need not adopt a code, but adopted codes must be at least as stringent; local administration still varies.Illinois Codes FAQ Source |
| Indiana | Statewide code, local enforcement | State building rules exist, but one- and two-family dwellings fall to the local government. If no local entity enforces them, the county may inspect; otherwise IDHS calls residential issues a private civil matter.Code Enforcement Source |
| Iowa | Local adoption | The State Building Code applies where a city or county adopts it by ordinance; permits, inspections and enforcement are local. Factory-built structure rules apply statewide. Many rural areas may lack residential inspections.Iowa Code Chapter 103A — State Building Code Source |
| Kansas | Local adoption | Kansas is a home-rule state with no statewide residential building code; cities and counties adopt and enforce codes. Many rural counties may have limited or no residential inspections.Kansas Building Energy Codes Source |
| Kentucky | Statewide code, local enforcement | The Kentucky Residential Code, based on the IRC with state amendments, applies statewide. Administration and inspection depend on whether a local program or the state handles the project; rural enforcement varies.Kentucky Residential Code Source |
| Louisiana | Statewide code, local enforcement | The Louisiana State Uniform Construction Code, currently the 2021 ICC codes with state amendments, applies statewide. Parishes and municipalities enforce it through local building officials or third-party providers.Laws, Rules and Regulations Source |
| Maine | Statewide code, local enforcement | MUBEC applies statewide, but enforcement is mandatory only in municipalities of more than 4,000 people. Smaller towns may choose to enforce it and cannot adopt a different code.MUBEC Rule Chapter 1 — Maine Office of State Fire Marshal Source |
| Maryland | Statewide code, local enforcement | The Maryland Building Performance Standards adopt the IBC, IRC and IECC with state changes. Each jurisdiction uses the same editions and may amend them locally, except energy and accessibility provisions.Maryland Building Codes — Maryland Department of Labor Source |
| Massachusetts | Statewide code | The Massachusetts State Building Code, 780 CMR, applies statewide and is enforced by each municipality's building commissioner or inspector of buildings under M.G.L. c. 143.780 CMR 103.1 — Municipal and State Enforcement (LII) Source |
| Michigan | Statewide code | The Michigan Residential Code applies statewide to one- and two-family dwellings. Enforcement may be by the state, county or local unit, so check LARA's jurisdiction list before applying.Building Permit Information — Michigan LARA Source |
| Minnesota | Statewide code, local enforcement | The State Building Code applies statewide and excludes agricultural buildings. Enforcement depends on local adoption; municipalities under 2,500 outside metro counties need not enforce it.Minn. Stat. §326B.121 — Compliance with State Building Code Source |
| Mississippi | Local adoption | A 2014 law required counties and municipalities to enact uniform building codes unless they opted out before November 30, 2014. Coverage of a given rural parcel must be confirmed locally.Mississippi Uniform Building Codes — Mississippi Insurance Department, State Fire Marshal Source |
| Missouri | Local adoption | There is no statewide residential building code. Cities and counties adopt their own codes, and DNR's jurisdiction directory warns that local amendments and trade codes need direct confirmation.Energy Codes by Jurisdiction Source |
| Montana | Limited or none statewide | Outside certified local jurisdictions, the state exempts private homes of four or fewer units from state building permits. Certified cities, counties and towns may require permits; trade permits need separate checking.Building Permit FAQ Source |
| Nebraska | Local adoption | Building codes are adopted and enforced by cities and counties. Where a local jurisdiction has not adopted an energy code, DWEE enforces the 2018 IECC.Nebraska Energy Codes Source |
| Nevada | Local adoption | NRS 278.580 lets each city or county adopt and enforce its own building code. There is no single statewide residential code, so permit requirements vary by county.NRS 278.580 — Building codes: Adoption Source |
| New Hampshire | Statewide code, local enforcement | RSA 155-A makes the state building code apply to buildings statewide. Towns enforce it through their own permit and inspection process, which varies widely between communities.State Building Code applicability — RSA 155-A:2 Source |
| New Jersey | Statewide code | The Uniform Construction Code applies in every municipality and is enforced by local construction officials. Its one- and two-family subcode adopts the 2024 IRC, New Jersey edition.Current Construction Codes Source |
| New Mexico | Statewide code | The 2021 New Mexico Residential Building Code applies statewide, with separate earthen and straw-bale codes. CID or a local authority issues permits; owner-builders of a primary residence need no contractor license.Rules, Laws, and Building Codes — NM Regulation and Licensing Department Source |
| New York | Statewide code, local enforcement | The 2025 Uniform and Energy Codes apply statewide outside New York City. Each city, town or village administers and enforces them, and may obtain approval for more restrictive standards.Uniform Code and Local Authority — NY Department of State Source |
| North Carolina | Statewide code, local enforcement | The NC State Building Code is adopted by the Building Code Council for use across the state. County or municipal inspection departments issue permits and conduct inspections.North Carolina State Building Codes — Office of State Fire Marshal Source |
| North Dakota | Local adoption | The State Building Code (2024 IRC-based, effective January 1, 2026) is not enforced by the state. Cities, counties and townships that choose to enforce codes must use it, with local amendments allowed.Building Codes — North Dakota Department of Commerce Source |
| Ohio | Statewide code, local enforcement | The Residential Code of Ohio applies statewide, but where no certified building department has jurisdiction, owners need not submit plans, get approvals, inspections or occupancy certificates. Agricultural buildings are exempt.Ohio Adm.Code 4101:8-1-01 (Residential Code of Ohio, scope and administration) Source |
| Oklahoma | Statewide code, local enforcement | The OUBCC sets statewide minimum residential and trade codes (2024 IRC effective September 14, 2026). Local governments enforce; in unincorporated areas the Construction Industries Board handles trade work.OUBCC Frequently Asked Questions Source |
| Oregon | Statewide code | ORS 455.040 makes the state building code applicable and uniform throughout Oregon. New residential construction and trade work need permits from the responsible building department, after land-use approval.ORS 455.040, State building code preempts local ordinances Source |
| Pennsylvania | Statewide code, local enforcement | The Uniform Construction Code (2018 I-codes, effective February 14, 2022) applies statewide. Over 90 percent of municipalities enforce it with their own staff or certified third-party agencies.Uniform Construction Code Source |
| Rhode Island | Statewide code, local enforcement | A single state building code, maintained through the State Building Office, applies in every municipality. Local building officials issue permits and also issue private well permits.State Building Office Source |
| South Carolina | Statewide code, local enforcement | S.C. Code 6-9-10 requires all counties and municipalities to enforce the state-adopted building, plumbing, electrical, mechanical, gas, energy and fire codes within their jurisdictions.S.C. Code Title 6, Chapter 9, Building Codes Source |
| South Dakota | Limited or none statewide | SDCL 11-10 sets a 2024 IBC-based design standard where no local ordinance exists; municipalities may adopt the 2024 IRC for homes. No state residential permit program exists, so enforcement depends on local government.SDCL Chapter 11-10 — Building Codes and Standards Source |
| Tennessee | Statewide code, local enforcement | The State Fire Marshal enforces the 2018 IRC for one- and two-family homes except where a locality has an enforcement exemption or has opted out by a two-thirds vote.Residential Permits Source |
| Texas | Limited or none statewide | Municipalities apply the International Residential Code with local amendments. In unincorporated areas, county residential standards apply only where a county meets statutory criteria and adopts an order.Texas Local Government Code Chapter 233 Source |
| Utah | Statewide code, local enforcement | The State Construction Code, including the 2021 International Residential Code with Appendix AQ for tiny houses, applies statewide with state and local amendments. Local building officials administer permits and inspections.Utah Code § 15A-2-103 Source |
| Vermont | Limited or none statewide | The Division of Fire Safety enforces codes for public buildings and rentals but does not regulate single-family owner-occupied dwellings. Residential energy standards and local bylaws may still apply.Division of Fire Safety presentation to Building Energy Code Working Group (2024) Source |
| Virginia | Statewide code, local enforcement | The Uniform Statewide Building Code applies to new construction and additions statewide. Local building inspections departments enforce it and may charge fees; DHCD maintains the code.Virginia Uniform Statewide Building Code (USBC) — DHCD Source |
| Washington | Statewide code, local enforcement | The State Building Code Council adopts the International Residential Code (WAC 51-51) statewide; counties and cities must adopt and enforce it, and local amendments cannot be less strict.Building Codes and Building Permits — MRSC Source |
| West Virginia | Local adoption | The State Building Code applies where a county or municipality adopts it, and the adopting jurisdiction enforces it. Some rural areas may have no local building permit, but other rules still apply.State Building Code Rule — West Virginia State Fire Marshal Source |
| Wisconsin | Statewide code | The Uniform Dwelling Code (SPS 320–325) applies to new one- and two-family homes statewide, enforced by a municipality, county or the state. Owner-occupants can obtain UDC permits themselves.Wisconsin's Uniform Dwelling Code — DSPS Source |
| Wyoming | Local adoption | No statewide residential building code was identified; the state's adopted codes do not list the IRC. Counties and cities decide on building permits, and state electrical permits apply when a utility connects power.Wyoming Department of Fire Prevention and Electrical Safety Source |
Checked October 2026. Laws change; open the linked source before relying on a summary. Found an error? Tell us.
Common questions
Which states do not have a statewide building code?
In our research, Alabama, Alaska, Arizona, Colorado, Delaware, Iowa, Kansas, Mississippi, Missouri, Montana, Nebraska, Nevada, North Dakota, South Dakota, Texas, Vermont, West Virginia, Wyoming leave residential code adoption mainly to local governments or apply only limited statewide requirements. In those states, a rural county may have no residential building inspections at all, while a nearby city enforces the full International Residential Code.
If there is no building code, do I need any permits?
Usually. Septic systems, wells, electrical work, driveways onto public roads, floodplain development and zoning often require permits even where no building permit exists. Lenders and insurers may also demand inspections or a certificate of occupancy.
What is the International Residential Code?
The International Residential Code (IRC) is a model code for one- and two-family homes published by the International Code Council. States and cities adopt a specific edition, sometimes with amendments. Its appendices cover tiny houses, strawbale and other alternative building methods, but only where the adopting jurisdiction includes them.
Can I build my own off-grid home?
Many states allow owners to build or do their own work on a home they will occupy, but rules on electrical and plumbing work, licensing exemptions and resale disclosures vary. Check the state guide and the county building office before starting.