# US Building Codes: The IRC, State by State How US residential building codes work — the IRC model code, adopted and amended state by state — and the rules you can calculate. - Canonical HTML: https://www.chippy.tools/building-codes/us/ - Publisher: Chippy Tools - Language: en - Updated: 2026-09-13 [Browse all topics](https://www.chippy.tools/building-codes/topics/)[Free web tools](https://www.chippy.tools/building-codes/tools/)[Printable references](https://www.chippy.tools/building-codes/printables/) [All countries](https://www.chippy.tools/building-codes/) [United States](https://www.chippy.tools/building-codes/us/) Topics Stairs - [California Guard Height: 42 Inches Under the CRC](https://www.chippy.tools/building-codes/us/ca/guard-height-42-inches/) - [IRC Stair & Guard Rules: Riser, Tread, Handrail, Guards](https://www.chippy.tools/building-codes/us/stairs/stair-and-barrier-requirements/) Footings - [US Footing Sizes & Frost Depth (IRC R403)](https://www.chippy.tools/building-codes/us/footings/footing-sizes-and-depth/) Room heights - [US Minimum Ceiling Heights (IRC R305)](https://www.chippy.tools/building-codes/us/rooms/minimum-ceiling-heights/) Ramps - [US Ramp Slopes (IRC R311.8)](https://www.chippy.tools/building-codes/us/ramps/ramp-gradients/) Wet areas - [Shower & Tub Wall Finish (IRC R307.2)](https://www.chippy.tools/building-codes/us/wet-areas/waterproofing-requirements/) By state - [Alaska](https://www.chippy.tools/building-codes/us/ak/) - [Alabama](https://www.chippy.tools/building-codes/us/al/) - [Arkansas](https://www.chippy.tools/building-codes/us/ar/) - [Arizona](https://www.chippy.tools/building-codes/us/az/) - [California](https://www.chippy.tools/building-codes/us/ca/) - [Colorado](https://www.chippy.tools/building-codes/us/co/) - [Connecticut](https://www.chippy.tools/building-codes/us/ct/) - [District of Columbia](https://www.chippy.tools/building-codes/us/dc/) - [Delaware](https://www.chippy.tools/building-codes/us/de/) - [Florida](https://www.chippy.tools/building-codes/us/fl/) - [Georgia](https://www.chippy.tools/building-codes/us/ga/) - [Hawaii](https://www.chippy.tools/building-codes/us/hi/) - [Iowa](https://www.chippy.tools/building-codes/us/ia/) - [Idaho](https://www.chippy.tools/building-codes/us/id/) - [Illinois](https://www.chippy.tools/building-codes/us/il/) - [Indiana](https://www.chippy.tools/building-codes/us/in/) - [Kansas](https://www.chippy.tools/building-codes/us/ks/) - [Kentucky](https://www.chippy.tools/building-codes/us/ky/) - [Louisiana](https://www.chippy.tools/building-codes/us/la/) - [Massachusetts](https://www.chippy.tools/building-codes/us/ma/) - [Maryland](https://www.chippy.tools/building-codes/us/md/) - [Maine](https://www.chippy.tools/building-codes/us/me/) - [Michigan](https://www.chippy.tools/building-codes/us/mi/) - [Minnesota](https://www.chippy.tools/building-codes/us/mn/) - [Missouri](https://www.chippy.tools/building-codes/us/mo/) - [Mississippi](https://www.chippy.tools/building-codes/us/ms/) - [Montana](https://www.chippy.tools/building-codes/us/mt/) - [North Carolina](https://www.chippy.tools/building-codes/us/nc/) - [North Dakota](https://www.chippy.tools/building-codes/us/nd/) - [Nebraska](https://www.chippy.tools/building-codes/us/ne/) - [New Hampshire](https://www.chippy.tools/building-codes/us/nh/) - [New Jersey](https://www.chippy.tools/building-codes/us/nj/) - [New Mexico](https://www.chippy.tools/building-codes/us/nm/) - [Nevada](https://www.chippy.tools/building-codes/us/nv/) - [New York](https://www.chippy.tools/building-codes/us/ny/) - [Ohio](https://www.chippy.tools/building-codes/us/oh/) - [Oklahoma](https://www.chippy.tools/building-codes/us/ok/) - [Oregon](https://www.chippy.tools/building-codes/us/or/) - [Pennsylvania](https://www.chippy.tools/building-codes/us/pa/) - [Rhode Island](https://www.chippy.tools/building-codes/us/ri/) - [South Carolina](https://www.chippy.tools/building-codes/us/sc/) - [South Dakota](https://www.chippy.tools/building-codes/us/sd/) - [Tennessee](https://www.chippy.tools/building-codes/us/tn/) - [Texas](https://www.chippy.tools/building-codes/us/tx/) - [Utah](https://www.chippy.tools/building-codes/us/ut/) - [Virginia](https://www.chippy.tools/building-codes/us/va/) - [Vermont](https://www.chippy.tools/building-codes/us/vt/) - [Western Australia](https://www.chippy.tools/building-codes/us/wa/) - [Wisconsin](https://www.chippy.tools/building-codes/us/wi/) - [West Virginia](https://www.chippy.tools/building-codes/us/wv/) - [Wyoming](https://www.chippy.tools/building-codes/us/wy/) Calculation guides - [Concrete Calculations: The Complete On-Site Guide](https://www.chippy.tools/building-codes/concrete/concrete-calculations-guide/) - [How to Calculate Concrete Volume for a Slab](https://www.chippy.tools/building-codes/concrete/concrete-volume-slab/) - [How Many Bags of Concrete Per m³? (20kg, 25kg, 40kg)](https://www.chippy.tools/building-codes/concrete/bags-of-concrete-per-m3/) - [Concrete for Post Holes: Volume Per Hole & Bags Needed](https://www.chippy.tools/building-codes/concrete/concrete-post-holes/) - [Concrete Mix Ratios Explained: 1:2:3, 1:2:4 & Water-Cement Ratio](https://www.chippy.tools/building-codes/concrete/concrete-mix-ratios/) - [Roof Pitch to Angle: Convert Rise/Run to Degrees & Grade](https://www.chippy.tools/building-codes/concrete/roof-pitch-to-angle/) - [Rafter Length Calculation: Run, Rise & Overhang](https://www.chippy.tools/building-codes/concrete/rafter-length/) - [Stair Rise & Run Setout: Riser, Going & the 2R+G Formula](https://www.chippy.tools/building-codes/concrete/stair-rise-and-run-setout/) - [How to Convert a Fall or Gradient: Ratio, Percentage & Degrees](https://www.chippy.tools/building-codes/concrete/fall-and-gradient-conversion/) - [Stud & Joist Spacing Takeoff: How Many at 400, 450 & 600 mm Centres](https://www.chippy.tools/building-codes/concrete/stud-and-joist-spacing-takeoff/) - [Gravel & Base Volume: Compacted Depth vs Loose-Fill Order Quantity](https://www.chippy.tools/building-codes/concrete/gravel-and-base-volume/) In this section [Browse all topics](https://www.chippy.tools/building-codes/topics/)[Free web tools](https://www.chippy.tools/building-codes/tools/)[Printable references](https://www.chippy.tools/building-codes/printables/) [All countries](https://www.chippy.tools/building-codes/) [United States](https://www.chippy.tools/building-codes/us/) Topics Stairs - [California Guard Height: 42 Inches Under the CRC](https://www.chippy.tools/building-codes/us/ca/guard-height-42-inches/) - [IRC Stair & Guard Rules: Riser, Tread, Handrail, Guards](https://www.chippy.tools/building-codes/us/stairs/stair-and-barrier-requirements/) Footings - [US Footing Sizes & Frost Depth (IRC R403)](https://www.chippy.tools/building-codes/us/footings/footing-sizes-and-depth/) Room heights - [US Minimum Ceiling Heights (IRC R305)](https://www.chippy.tools/building-codes/us/rooms/minimum-ceiling-heights/) Ramps - [US Ramp Slopes (IRC R311.8)](https://www.chippy.tools/building-codes/us/ramps/ramp-gradients/) Wet areas - [Shower & Tub Wall Finish (IRC R307.2)](https://www.chippy.tools/building-codes/us/wet-areas/waterproofing-requirements/) By state - [Alaska](https://www.chippy.tools/building-codes/us/ak/) - [Alabama](https://www.chippy.tools/building-codes/us/al/) - [Arkansas](https://www.chippy.tools/building-codes/us/ar/) - [Arizona](https://www.chippy.tools/building-codes/us/az/) - [California](https://www.chippy.tools/building-codes/us/ca/) - [Colorado](https://www.chippy.tools/building-codes/us/co/) - [Connecticut](https://www.chippy.tools/building-codes/us/ct/) - [District of Columbia](https://www.chippy.tools/building-codes/us/dc/) - [Delaware](https://www.chippy.tools/building-codes/us/de/) - [Florida](https://www.chippy.tools/building-codes/us/fl/) - [Georgia](https://www.chippy.tools/building-codes/us/ga/) - [Hawaii](https://www.chippy.tools/building-codes/us/hi/) - [Iowa](https://www.chippy.tools/building-codes/us/ia/) - [Idaho](https://www.chippy.tools/building-codes/us/id/) - [Illinois](https://www.chippy.tools/building-codes/us/il/) - [Indiana](https://www.chippy.tools/building-codes/us/in/) - [Kansas](https://www.chippy.tools/building-codes/us/ks/) - [Kentucky](https://www.chippy.tools/building-codes/us/ky/) - [Louisiana](https://www.chippy.tools/building-codes/us/la/) - [Massachusetts](https://www.chippy.tools/building-codes/us/ma/) - [Maryland](https://www.chippy.tools/building-codes/us/md/) - [Maine](https://www.chippy.tools/building-codes/us/me/) - [Michigan](https://www.chippy.tools/building-codes/us/mi/) - [Minnesota](https://www.chippy.tools/building-codes/us/mn/) - [Missouri](https://www.chippy.tools/building-codes/us/mo/) - [Mississippi](https://www.chippy.tools/building-codes/us/ms/) - [Montana](https://www.chippy.tools/building-codes/us/mt/) - [North Carolina](https://www.chippy.tools/building-codes/us/nc/) - [North Dakota](https://www.chippy.tools/building-codes/us/nd/) - [Nebraska](https://www.chippy.tools/building-codes/us/ne/) - [New Hampshire](https://www.chippy.tools/building-codes/us/nh/) - [New Jersey](https://www.chippy.tools/building-codes/us/nj/) - [New Mexico](https://www.chippy.tools/building-codes/us/nm/) - [Nevada](https://www.chippy.tools/building-codes/us/nv/) - [New York](https://www.chippy.tools/building-codes/us/ny/) - [Ohio](https://www.chippy.tools/building-codes/us/oh/) - [Oklahoma](https://www.chippy.tools/building-codes/us/ok/) - [Oregon](https://www.chippy.tools/building-codes/us/or/) - [Pennsylvania](https://www.chippy.tools/building-codes/us/pa/) - [Rhode Island](https://www.chippy.tools/building-codes/us/ri/) - [South Carolina](https://www.chippy.tools/building-codes/us/sc/) - [South Dakota](https://www.chippy.tools/building-codes/us/sd/) - [Tennessee](https://www.chippy.tools/building-codes/us/tn/) - [Texas](https://www.chippy.tools/building-codes/us/tx/) - [Utah](https://www.chippy.tools/building-codes/us/ut/) - [Virginia](https://www.chippy.tools/building-codes/us/va/) - [Vermont](https://www.chippy.tools/building-codes/us/vt/) - [Western Australia](https://www.chippy.tools/building-codes/us/wa/) - [Wisconsin](https://www.chippy.tools/building-codes/us/wi/) - [West Virginia](https://www.chippy.tools/building-codes/us/wv/) - [Wyoming](https://www.chippy.tools/building-codes/us/wy/) Calculation guides - [Concrete Calculations: The Complete On-Site Guide](https://www.chippy.tools/building-codes/concrete/concrete-calculations-guide/) - [How to Calculate Concrete Volume for a Slab](https://www.chippy.tools/building-codes/concrete/concrete-volume-slab/) - [How Many Bags of Concrete Per m³? (20kg, 25kg, 40kg)](https://www.chippy.tools/building-codes/concrete/bags-of-concrete-per-m3/) - [Concrete for Post Holes: Volume Per Hole & Bags Needed](https://www.chippy.tools/building-codes/concrete/concrete-post-holes/) - [Concrete Mix Ratios Explained: 1:2:3, 1:2:4 & Water-Cement Ratio](https://www.chippy.tools/building-codes/concrete/concrete-mix-ratios/) - [Roof Pitch to Angle: Convert Rise/Run to Degrees & Grade](https://www.chippy.tools/building-codes/concrete/roof-pitch-to-angle/) - [Rafter Length Calculation: Run, Rise & Overhang](https://www.chippy.tools/building-codes/concrete/rafter-length/) - [Stair Rise & Run Setout: Riser, Going & the 2R+G Formula](https://www.chippy.tools/building-codes/concrete/stair-rise-and-run-setout/) - [How to Convert a Fall or Gradient: Ratio, Percentage & Degrees](https://www.chippy.tools/building-codes/concrete/fall-and-gradient-conversion/) - [Stud & Joist Spacing Takeoff: How Many at 400, 450 & 600 mm Centres](https://www.chippy.tools/building-codes/concrete/stud-and-joist-spacing-takeoff/) - [Gravel & Base Volume: Compacted Depth vs Loose-Fill Order Quantity](https://www.chippy.tools/building-codes/concrete/gravel-and-base-volume/) [Building Codes](https://www.chippy.tools/building-codes/) United States # US Building Codes: The IRC, State by State US residential building codes are set state by state, each adopting a different edition of the IRC with local amendments — and some states run their own codes entirely. This hub tracks what applies in your state. ## Which edition applies, by state | Jurisdiction | Current code | Adoption / transition | Status | |------------------------------------------------------------------------|--------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------|---------| | [Alaska](https://www.chippy.tools/building-codes/us/ak/) | AHFC Residential Code (2018 IRC) | statewide minimum for 1-4 unit residential per HB 80/AHFC regulation, effective Jan 1, 2026; previously no… | Adopted | | [Alabama](https://www.chippy.tools/building-codes/us/al/) | Alabama Residential Code (2015) | statewide, effective 10/1/2016; authority transferred to Home Builders Licensure Board Oct 2024, new edition… | Adopted | | [Arkansas](https://www.chippy.tools/building-codes/us/ar/) | Arkansas Residential Code (2021) | statewide (Arkansas Fire Prevention Code Vol. III), effective Jan 1, 2023 | Adopted | | [Arizona](https://www.chippy.tools/building-codes/us/az/) | local adoption | local adoption — no mandatory statewide residential code; cities/counties adopt & amend their own IRC edition | Local | | [California](https://www.chippy.tools/building-codes/us/ca/) | California Residential Code (2025) | California uses the California Residential Code (2025 CRC, based on IRC 2024), in force since 1 January 2026.… | Adopted | | [Colorado](https://www.chippy.tools/building-codes/us/co/) | local adoption | local adoption — no mandatory statewide residential building code; jurisdictions adopt & amend their own IRC… | Local | | [Connecticut](https://www.chippy.tools/building-codes/us/ct/) | 2022 Connecticut State Building Code (own state code, 2021 IRC portion) | mandatory statewide, effective Oct 1, 2022 | Adopted | | [Delaware](https://www.chippy.tools/building-codes/us/de/) | local adoption | local adoption — no mandatory statewide residential code; counties/towns adopt own IRC edition (e.g. Sussex… | Local | | [Florida](https://www.chippy.tools/building-codes/us/fl/) | Florida Building Code, Residential (8th Edition, 2023) | Florida uses the Florida Building Code, Residential (8th Edition, 2023, based on IRC 2021), effective 31… | Adopted | | [Georgia](https://www.chippy.tools/building-codes/us/ga/) | Georgia State Minimum Standard One- and Two-Family Dwelling Code (IRC… | Statewide mandatory; new mandatory codes effective January 1, 2026 (2024 IRC with GA amendments) | Adopted | | [Hawaii](https://www.chippy.tools/building-codes/us/hi/) | Hawaii State Residential Code (IRC 2021) | State code based on 2021 IRC, effective March 6, 2022; each of the 4 counties must adopt/amend within 2 years,… | Adopted | | [Iowa](https://www.chippy.tools/building-codes/us/ia/) | Iowa State Building Code residential provisions (Iowa Residential Code,… | The Iowa State Building Code residential provisions are based on the 2015 IRC; for new one- and two-family… | Local | | [Idaho](https://www.chippy.tools/building-codes/us/id/) | Idaho Residential Code (2020 Edition, based on IRC 2018) | Statewide, effective January 1, 2021; adopted by state statute via Idaho Building Code Board (DOPL) | Adopted | | [Illinois](https://www.chippy.tools/building-codes/us/il/) | IRC (edition varies by jurisdiction) | No single statewide IRC edition; local jurisdictions adopt. Public Act 103-0510 requires a statewide baseline… | Local | | [Indiana](https://www.chippy.tools/building-codes/us/in/) | Indiana Residential Code (2020 Edition, based on IRC 2018) | Statewide (Indiana's own state-amended residential code based on 2018 IRC), adopted by the Indiana Fire… | Adopted | | [Kansas](https://www.chippy.tools/building-codes/us/ks/) | IRC (edition varies by jurisdiction) | No statewide residential code; home-rule local adoption. Commonly adopted edition among major cities (Wichita,… | Local | | [Kentucky](https://www.chippy.tools/building-codes/us/ky/) | 2018 Kentucky Residential Code (3rd Edition) | Statewide mandatory; 3rd Edition effective Aug 1, 2024. NOTE: named '2018 KRC' but its model base is the 2015… | Adopted | | [Louisiana](https://www.chippy.tools/building-codes/us/la/) | Louisiana State Uniform Construction Code (2021 IRC) | Statewide mandatory for new one/two-family dwellings; 2021 IRC effective Jan 1, 2023. Enforcement applies to… | Adopted | | [Massachusetts](https://www.chippy.tools/building-codes/us/ma/) | Massachusetts Residential Code, 10th Edition (780 CMR, Ch. 51) — 2021… | Statewide mandatory; 10th Edition effective Oct 11, 2024, concurrency period with 9th Edition ended June 30,… | Adopted | | [Maryland](https://www.chippy.tools/building-codes/us/md/) | Maryland Building Performance Standards (MBPS) — 2021 IRC | Statewide uniform standard (MBPS, COMAR 09.12.51), 2021 IRC effective May 29, 2023; local jurisdictions… | Adopted | | [Maine](https://www.chippy.tools/building-codes/us/me/) | Maine Uniform Building and Energy Code (MUBEC) — 2021 IRC | Statewide uniform code; updated from 2015 to 2021 I-codes effective ~Apr 7, 2025. Statewide standard, but… | Adopted | | [Michigan](https://www.chippy.tools/building-codes/us/mi/) | IRC (edition contested) — 2021 Michigan Residential Code adopted but… | Statewide mandatory. 2021 Michigan Residential Code (2021 IRC base) filed May 1, 2025, effective date Aug 29,… | Adopted | | [Minnesota](https://www.chippy.tools/building-codes/us/mn/) | 2020 Minnesota Residential Code (Minn. Rules Ch. 1309) — 2018 IRC | Statewide mandatory; adopts by reference the 2018 IRC (Ch. 2-10 etc.) as amended, effective Mar 31, 2020. | Adopted | | [Missouri](https://www.chippy.tools/building-codes/us/mo/) | No statewide residential code; local adoption (edition varies, commonly… | Local adoption only — no mandatory statewide building/residential code; cities and counties adopt their own… | Local | | [Mississippi](https://www.chippy.tools/building-codes/us/ms/) | IRC 2021 (statewide minimum; adoption left to local jurisdictions) | Local adoption; MS Building Codes Council discretionary statewide minimum = 2021 IRC, published eff. July 1,… | Local | | [Montana](https://www.chippy.tools/building-codes/us/mt/) | Montana Residential Code (2021 IRC) | Mandatory statewide; 2021 IRC incorporated by reference via ARM 24.301.154 (initial 2021 adoption eff. 2022;… | Adopted | | [North Carolina](https://www.chippy.tools/building-codes/us/nc/) | 2018 North Carolina Residential Code (NCRC) | Statewide own-cycle code; 2018 NCRC (based on 2015 IRC) effective Jan 1 2019 and STILL current — the 2024 NC… | Adopted | | [North Dakota](https://www.chippy.tools/building-codes/us/nd/) | North Dakota State Building Code — 2024 IRC | Local adoption (opt-in): 2024 IBC/IRC state code effective Jan 1 2026; mandatory for state/local govt… | Local | | [Nebraska](https://www.chippy.tools/building-codes/us/ne/) | Nebraska State Building Code (2018 IRC) | State Building Code adopts 2018 IRC; codes largely enforced by local jurisdictions, but since Aug 28, 2021 the… | Local | | [New Hampshire](https://www.chippy.tools/building-codes/us/nh/) | NH State Building Code — Residential Code for One- and Two-Family… | Mandatory statewide; 2021 IRC effective July 1, 2024. A 2024 IRC update is scheduled effective July 1, 2026… | Adopted | | [New Jersey](https://www.chippy.tools/building-codes/us/nj/) | NJ Uniform Construction Code — One- and Two-Family Dwelling Subcode… | Mandatory statewide via UCC (N.J.A.C. 5:23-3.21); 2021 IRC NJ Edition subcode effective March 2023 | Adopted | | [New Mexico](https://www.chippy.tools/building-codes/us/nm/) | New Mexico Residential Code 2021 (NMRC) | Statewide; 2021 NMRC (14.7.3 NMAC) in effect (phased 2023–2024) | Adopted | | [Nevada](https://www.chippy.tools/building-codes/us/nv/) | No single statewide residential code; local adoption (edition varies,… | Local adoption — permits issued/enforced by city & county building depts (e.g. Clark Co./Las Vegas 2018 IRC,… | Local | | [New York](https://www.chippy.tools/building-codes/us/ny/) | Residential Code of New York State (own code) — 2025 RCNYS (2024 IRC)… | Statewide own code; 2025 RCNYS adopted (Notice of Adoption 2025-07-24, derivative of 2024 IRC), replacing 2020… | Adopted | | [Ohio](https://www.chippy.tools/building-codes/us/oh/) | 2019 Residential Code of Ohio (RCO) | Statewide code (2019 RCO, based on 2018 IRC, effective Jul 1 2019; amended eff. Mar 1 2024); enforcement of… | Adopted | | [Oklahoma](https://www.chippy.tools/building-codes/us/ok/) | Oklahoma Residential Code — 2018 IRC | Statewide minimum code set by OUBCC; 2018 IRC (amended, eff. Sep 14 2022) in effect until Sep 14 2026, when… | Adopted | | [Oregon](https://www.chippy.tools/building-codes/us/or/) | 2023 Oregon Residential Specialty Code (ORSC) | Statewide (no local amendments); 2023 ORSC based on 2021 IRC, effective Oct 1 2023, mandatory Apr 1 2024 | Adopted | | [Pennsylvania](https://www.chippy.tools/building-codes/us/pa/) | Pennsylvania Uniform Construction Code (UCC) — 2021 IRC | statewide UCC; effective Jan 1, 2026 for permit applications (prior permits: 2018 IRC) | Adopted | | [Rhode Island](https://www.chippy.tools/building-codes/us/ri/) | RI One- and Two-Family Dwelling Code SBC-2-2021 | statewide; effective Feb 1, 2022 (own named SBC-2 code, directly based on IRC) | Adopted | | [South Carolina](https://www.chippy.tools/building-codes/us/sc/) | South Carolina Residential Code (2018) | statewide; effective Jan 1, 2020 (2024 IRC in adoption/comment process, not yet effective) | Adopted | | [South Dakota](https://www.chippy.tools/building-codes/us/sd/) | local adoption — no statewide residential (IRC) code | local adoption; state has no mandatory statewide one/two-family dwelling code (edition varies by jurisdiction) | Local | | [Tennessee](https://www.chippy.tools/building-codes/us/tn/) | Tennessee Residential Code (2018) | statewide minimum; some local jurisdictions adopt newer (e.g. Nashville 2024, Wilson Co. 2021) or counties may… | Adopted | | [Texas](https://www.chippy.tools/building-codes/us/tx/) | IRC 2012 statewide minimum; actual edition set by local jurisdiction… | statewide floor only (HB 738, eff. 2022 sets 2012 IRC as municipal minimum); cities/counties adopt & amend,… | Adopted | | [Utah](https://www.chippy.tools/building-codes/us/ut/) | Utah State Construction Code — 2021 IRC | statewide; effective Jul 1, 2023 (2024 IRC not confirmed adopted; could not fully rule out a 2025 update) | Adopted | | [Virginia](https://www.chippy.tools/building-codes/us/va/) | 2021 Virginia Residential Code (part of Virginia USBC) | Mandatory statewide (USBC). Effective Jan 18, 2024; 2021 provisions mandatory for all new permits from Jan 18,… | Adopted | | [Vermont](https://www.chippy.tools/building-codes/us/vt/) | No statewide residential building code for owner-occupied 1-2 family… | No statewide IRC-based residential code; VT Fire & Building Safety Code exempts owner-occupied single-family… | Local | | [Washington](https://www.chippy.tools/building-codes/us/wa/) | 2021 Washington State Residential Code (WSRC) | Mandatory statewide (WAC 51-51), with WA amendments. Effective March 15, 2024 | Adopted | | [Wisconsin](https://www.chippy.tools/building-codes/us/wi/) | Wisconsin Uniform Dwelling Code (UDC), SPS 320-325 | Mandatory statewide for new 1- & 2-family dwellings; administered by DSPS; code text updated monthly (current… | Adopted | | [West Virginia](https://www.chippy.tools/building-codes/us/wv/) | West Virginia Residential Code (2018 IRC based) | State Building Code adopted by WV State Fire Commission; effective Aug 1, 2022. Statewide standard but… | Adopted | | [Wyoming](https://www.chippy.tools/building-codes/us/wy/) | IRC (edition not confirmed statewide) - local adoption | local adoption | Local | | [District of Columbia](https://www.chippy.tools/building-codes/us/dc/) | 2017 DC Residential Code (part of 2017 DC Construction Codes) | Mandatory (single jurisdiction). 2017 DC Construction Codes (based on 2015 I-codes) effective May 29, 2020;… | Adopted | - [Alaska](https://www.chippy.tools/building-codes/us/ak/) Adopted Current AHFC Residential Code (2018 IRC) statewide minimum for 1-4 unit residential per HB 80/AHFC regulation, effective Jan 1, 2026; previously no statewide 1-2 family code (local enforcement only) - [Alabama](https://www.chippy.tools/building-codes/us/al/) Adopted Current Alabama Residential Code (2015) statewide, effective 10/1/2016; authority transferred to Home Builders Licensure Board Oct 2024, new edition pending (not yet confirmed adopted) - [Arkansas](https://www.chippy.tools/building-codes/us/ar/) Adopted Current Arkansas Residential Code (2021) statewide (Arkansas Fire Prevention Code Vol. III), effective Jan 1, 2023 - [Arizona](https://www.chippy.tools/building-codes/us/az/) Local Current local adoption local adoption — no mandatory statewide residential code; cities/counties adopt & amend their own IRC edition - [California](https://www.chippy.tools/building-codes/us/ca/) Adopted Current California Residential Code (2025) California uses the California Residential Code (2025 CRC, based on IRC 2024), in force since 1 January 2026. Stair geometry matches the IRC, but California requires taller 42-inch (1067 mm) guards. - [Colorado](https://www.chippy.tools/building-codes/us/co/) Local Current local adoption local adoption — no mandatory statewide residential building code; jurisdictions adopt & amend their own IRC edition (statewide energy code board sets minimum IECC only) - [Connecticut](https://www.chippy.tools/building-codes/us/ct/) Adopted Current 2022 Connecticut State Building Code (own state code, 2021 IRC portion) mandatory statewide, effective Oct 1, 2022 - [Delaware](https://www.chippy.tools/building-codes/us/de/) Local Current local adoption local adoption — no mandatory statewide residential code; counties/towns adopt own IRC edition (e.g. Sussex Co. 2021, New Castle 2018) - [Florida](https://www.chippy.tools/building-codes/us/fl/) Adopted Current Florida Building Code, Residential (8th Edition, 2023) Florida uses the Florida Building Code, Residential (8th Edition, 2023, based on IRC 2021), effective 31 December 2023. Its amendments target wind and the High-Velocity Hurricane Zone, not stair… - [Georgia](https://www.chippy.tools/building-codes/us/ga/) Adopted Current Georgia State Minimum Standard One- and Two-Family Dwelling Code (IRC 2024 with Georgia… Statewide mandatory; new mandatory codes effective January 1, 2026 (2024 IRC with GA amendments) - [Hawaii](https://www.chippy.tools/building-codes/us/hi/) Adopted Current Hawaii State Residential Code (IRC 2021) State code based on 2021 IRC, effective March 6, 2022; each of the 4 counties must adopt/amend within 2 years, and the state code becomes the interim county code if a county fails to adopt - [Iowa](https://www.chippy.tools/building-codes/us/ia/) Local Current Iowa State Building Code residential provisions (Iowa Residential Code, based on IRC 2015) The Iowa State Building Code residential provisions are based on the 2015 IRC; for new one- and two-family dwellings, adoption is a LOCAL OPTION (Iowa Code Ch. 103A lets jurisdictions adopt other… - [Idaho](https://www.chippy.tools/building-codes/us/id/) Adopted Current Idaho Residential Code (2020 Edition, based on IRC 2018) Statewide, effective January 1, 2021; adopted by state statute via Idaho Building Code Board (DOPL) - [Illinois](https://www.chippy.tools/building-codes/us/il/) Local Current IRC (edition varies by jurisdiction) No single statewide IRC edition; local jurisdictions adopt. Public Act 103-0510 requires a statewide baseline effective 1/1/2025 — local residential codes must be at least as stringent as the IRC… - [Indiana](https://www.chippy.tools/building-codes/us/in/) Adopted Current Indiana Residential Code (2020 Edition, based on IRC 2018) Statewide (Indiana's own state-amended residential code based on 2018 IRC), adopted by the Indiana Fire Prevention and Building Safety Commission - [Kansas](https://www.chippy.tools/building-codes/us/ks/) Local Current IRC (edition varies by jurisdiction) No statewide residential code; home-rule local adoption. Commonly adopted edition among major cities (Wichita, Overland Park, Kansas City KS) is the 2018 IRC with local amendments - [Kentucky](https://www.chippy.tools/building-codes/us/ky/) Adopted Current 2018 Kentucky Residential Code (3rd Edition) Statewide mandatory; 3rd Edition effective Aug 1, 2024. NOTE: named '2018 KRC' but its model base is the 2015 IRC (with KY amendments), not the 2018 IRC. - [Louisiana](https://www.chippy.tools/building-codes/us/la/) Adopted Current Louisiana State Uniform Construction Code (2021 IRC) Statewide mandatory for new one/two-family dwellings; 2021 IRC effective Jan 1, 2023. Enforcement applies to new construction/additions/major alterations. - [Massachusetts](https://www.chippy.tools/building-codes/us/ma/) Adopted Current Massachusetts Residential Code, 10th Edition (780 CMR, Ch. 51) — 2021 IRC Statewide mandatory; 10th Edition effective Oct 11, 2024, concurrency period with 9th Edition ended June 30, 2025 (so 10th Ed. is now the sole code). - [Maryland](https://www.chippy.tools/building-codes/us/md/) Adopted Current Maryland Building Performance Standards (MBPS) — 2021 IRC Statewide uniform standard (MBPS, COMAR 09.12.51), 2021 IRC effective May 29, 2023; local jurisdictions required to implement/enforce by May 29, 2024 and may adopt local amendments. - [Maine](https://www.chippy.tools/building-codes/us/me/) Adopted Current Maine Uniform Building and Energy Code (MUBEC) — 2021 IRC Statewide uniform code; updated from 2015 to 2021 I-codes effective ~Apr 7, 2025. Statewide standard, but enforcement is mandatory only in municipalities that enforce MUBEC (small towns under ~4,000… - [Michigan](https://www.chippy.tools/building-codes/us/mi/) Adopted Current IRC (edition contested) — 2021 Michigan Residential Code adopted but implementation… Statewide mandatory. 2021 Michigan Residential Code (2021 IRC base) filed May 1, 2025, effective date Aug 29, 2025 and the 2015 scope rule was rescinded effective that date; HOWEVER a July 7, 2025… - [Minnesota](https://www.chippy.tools/building-codes/us/mn/) Adopted Current 2020 Minnesota Residential Code (Minn. Rules Ch. 1309) — 2018 IRC Statewide mandatory; adopts by reference the 2018 IRC (Ch. 2-10 etc.) as amended, effective Mar 31, 2020. - [Missouri](https://www.chippy.tools/building-codes/us/mo/) Local Current No statewide residential code; local adoption (edition varies, commonly IRC 2015-2018) Local adoption only — no mandatory statewide building/residential code; cities and counties adopt their own IRC edition (KC, St. Louis have local amendments) - [Mississippi](https://www.chippy.tools/building-codes/us/ms/) Local Current IRC 2021 (statewide minimum; adoption left to local jurisdictions) Local adoption; MS Building Codes Council discretionary statewide minimum = 2021 IRC, published eff. July 1, 2024; cities/counties choose from the 3 most recent council-approved editions - [Montana](https://www.chippy.tools/building-codes/us/mt/) Adopted Current Montana Residential Code (2021 IRC) Mandatory statewide; 2021 IRC incorporated by reference via ARM 24.301.154 (initial 2021 adoption eff. 2022; re-adoption eff. Sept 21, 2024) - [North Carolina](https://www.chippy.tools/building-codes/us/nc/) Adopted Current 2018 North Carolina Residential Code (NCRC) Statewide own-cycle code; 2018 NCRC (based on 2015 IRC) effective Jan 1 2019 and STILL current — the 2024 NC code was delayed/postponed indefinitely (Mar/Apr 2025) - [North Dakota](https://www.chippy.tools/building-codes/us/nd/) Local Current North Dakota State Building Code — 2024 IRC Local adoption (opt-in): 2024 IBC/IRC state code effective Jan 1 2026; mandatory for state/local govt buildings & schools, and any city/county/township that chooses to enforce building codes must… - [Nebraska](https://www.chippy.tools/building-codes/us/ne/) Local Current Nebraska State Building Code (2018 IRC) State Building Code adopts 2018 IRC; codes largely enforced by local jurisdictions, but since Aug 28, 2021 the state code applies as the default where a locality has not adopted a conforming code… - [New Hampshire](https://www.chippy.tools/building-codes/us/nh/) Adopted Current NH State Building Code — Residential Code for One- and Two-Family Dwellings (2021 IRC) Mandatory statewide; 2021 IRC effective July 1, 2024. A 2024 IRC update is scheduled effective July 1, 2026 with a concurrence period (July 1-Dec 31, 2026) during which either the 2021 or 2024 edition… - [New Jersey](https://www.chippy.tools/building-codes/us/nj/) Adopted Current NJ Uniform Construction Code — One- and Two-Family Dwelling Subcode (2021 IRC, New Jersey… Mandatory statewide via UCC (N.J.A.C. 5:23-3.21); 2021 IRC NJ Edition subcode effective March 2023 - [New Mexico](https://www.chippy.tools/building-codes/us/nm/) Adopted Current New Mexico Residential Code 2021 (NMRC) Statewide; 2021 NMRC (14.7.3 NMAC) in effect (phased 2023–2024) - [Nevada](https://www.chippy.tools/building-codes/us/nv/) Local Current No single statewide residential code; local adoption (edition varies, IRC 2018-2024) Local adoption — permits issued/enforced by city & county building depts (e.g. Clark Co./Las Vegas 2018 IRC, Washoe Co. 2024 IRC). State Public Works adopted 2024 IRC only for state-owned projects - [New York](https://www.chippy.tools/building-codes/us/ny/) Adopted Current Residential Code of New York State (own code) — 2025 RCNYS (2024 IRC) being phased in;… Statewide own code; 2025 RCNYS adopted (Notice of Adoption 2025-07-24, derivative of 2024 IRC), replacing 2020 RCNYS (2018 IRC); effective date not firmly confirmed. NYC runs its own construction… - [Ohio](https://www.chippy.tools/building-codes/us/oh/) Adopted Current 2019 Residential Code of Ohio (RCO) Statewide code (2019 RCO, based on 2018 IRC, effective Jul 1 2019; amended eff. Mar 1 2024); enforcement of 1–3 family dwellings is at local jurisdiction option - [Oklahoma](https://www.chippy.tools/building-codes/us/ok/) Adopted Current Oklahoma Residential Code — 2018 IRC Statewide minimum code set by OUBCC; 2018 IRC (amended, eff. Sep 14 2022) in effect until Sep 14 2026, when 2024 IRC takes over. Adopted/enforced by local jurisdictions. - [Oregon](https://www.chippy.tools/building-codes/us/or/) Adopted Current 2023 Oregon Residential Specialty Code (ORSC) Statewide (no local amendments); 2023 ORSC based on 2021 IRC, effective Oct 1 2023, mandatory Apr 1 2024 - [Pennsylvania](https://www.chippy.tools/building-codes/us/pa/) Adopted Current Pennsylvania Uniform Construction Code (UCC) — 2021 IRC statewide UCC; effective Jan 1, 2026 for permit applications (prior permits: 2018 IRC) - [Rhode Island](https://www.chippy.tools/building-codes/us/ri/) Adopted Current RI One- and Two-Family Dwelling Code SBC-2-2021 statewide; effective Feb 1, 2022 (own named SBC-2 code, directly based on IRC) - [South Carolina](https://www.chippy.tools/building-codes/us/sc/) Adopted Current South Carolina Residential Code (2018) statewide; effective Jan 1, 2020 (2024 IRC in adoption/comment process, not yet effective) - [South Dakota](https://www.chippy.tools/building-codes/us/sd/) Local Current local adoption — no statewide residential (IRC) code local adoption; state has no mandatory statewide one/two-family dwelling code (edition varies by jurisdiction) - [Tennessee](https://www.chippy.tools/building-codes/us/tn/) Adopted Current Tennessee Residential Code (2018) statewide minimum; some local jurisdictions adopt newer (e.g. Nashville 2024, Wilson Co. 2021) or counties may opt out - [Texas](https://www.chippy.tools/building-codes/us/tx/) Adopted Current IRC 2012 statewide minimum; actual edition set by local jurisdiction (commonly newer) statewide floor only (HB 738, eff. 2022 sets 2012 IRC as municipal minimum); cities/counties adopt & amend, often 2015–2021 - [Utah](https://www.chippy.tools/building-codes/us/ut/) Adopted Current Utah State Construction Code — 2021 IRC statewide; effective Jul 1, 2023 (2024 IRC not confirmed adopted; could not fully rule out a 2025 update) - [Virginia](https://www.chippy.tools/building-codes/us/va/) Adopted Current 2021 Virginia Residential Code (part of Virginia USBC) Mandatory statewide (USBC). Effective Jan 18, 2024; 2021 provisions mandatory for all new permits from Jan 18, 2025 - [Vermont](https://www.chippy.tools/building-codes/us/vt/) Local Current No statewide residential building code for owner-occupied 1-2 family dwellings (only RBES… No statewide IRC-based residential code; VT Fire & Building Safety Code exempts owner-occupied single-family homes. Only statewide requirement for new residential is the Residential Building Energy… - [Washington](https://www.chippy.tools/building-codes/us/wa/) Adopted Current 2021 Washington State Residential Code (WSRC) Mandatory statewide (WAC 51-51), with WA amendments. Effective March 15, 2024 - [Wisconsin](https://www.chippy.tools/building-codes/us/wi/) Adopted Current Wisconsin Uniform Dwelling Code (UDC), SPS 320-325 Mandatory statewide for new 1- & 2-family dwellings; administered by DSPS; code text updated monthly (current per WI Administrative Register) - [West Virginia](https://www.chippy.tools/building-codes/us/wv/) Adopted Current West Virginia Residential Code (2018 IRC based) State Building Code adopted by WV State Fire Commission; effective Aug 1, 2022. Statewide standard but enforcement requires local adoption by municipalities/counties - [Wyoming](https://www.chippy.tools/building-codes/us/wy/) Local Current IRC (edition not confirmed statewide) - local adoption local adoption - [District of Columbia](https://www.chippy.tools/building-codes/us/dc/) Adopted Current 2017 DC Residential Code (part of 2017 DC Construction Codes) Mandatory (single jurisdiction). 2017 DC Construction Codes (based on 2015 I-codes) effective May 29, 2020; modernization to newer editions underway but not yet adopted as of 2026 Adoption timing changes on government timelines — entries marked *Verify* are being confirmed with the relevant authority. ## Rules by topic Find guidance for the work you are doing, then confirm the requirements for your building and location. ### Stairs - [California Guard Height: 42 Inches Under the CRC](https://www.chippy.tools/building-codes/us/ca/guard-height-42-inches/) - [IRC Stair & Guard Rules: Riser, Tread, Handrail, Guards](https://www.chippy.tools/building-codes/us/stairs/stair-and-barrier-requirements/) ### Footings & slabs - [US Footing Sizes & Frost Depth (IRC R403)](https://www.chippy.tools/building-codes/us/footings/footing-sizes-and-depth/) ### Room heights - [US Minimum Ceiling Heights (IRC R305)](https://www.chippy.tools/building-codes/us/rooms/minimum-ceiling-heights/) ### Ramps - [US Ramp Slopes (IRC R311.8)](https://www.chippy.tools/building-codes/us/ramps/ramp-gradients/) ### Wet areas - [Shower & Tub Wall Finish (IRC R307.2)](https://www.chippy.tools/building-codes/us/wet-areas/waterproofing-requirements/) ## How the code works here There is no single US building code. The rule most homes are built to is the **International Residential Code (IRC)** — the “I-codes” written by the ICC. But the IRC is a **model code**. On its own it has no force. It is just a template. A code only becomes law when your **state and/or your town adopts it** — and they almost always change parts of it first. Those changes are called **amendments**. So the book you actually build to is the IRC *as your state and town wrote it*, not the plain ICC text. ## Which edition is in force? It’s a patchwork. Different places are on different editions. Many towns are still on **IRC 2018 or 2015**, while others have moved to **2021 or 2024**. And some places don’t use the IRC at all: - **California** runs its own **California Residential Code (CRC)**. - **Wisconsin** has its own state code. - **New York City** and **Chicago** run their own codes too. The base numbers have stayed steady across the 2015–2024 editions, so the figures on the stair page below are a solid starting point. But they are a starting point, not the final word. ## The first job on every job Before you set out a single step, **confirm two things** for the exact spot you’re building: 1. **Which edition** of the IRC (or local code) your state and town have adopted. 2. **What amendments** they’ve added on top. Your local building department is the one who signs off, so their adopted-and-amended edition is the number that counts — not the plain ICC book, and not what the next county does. ## By state - [Alaska](https://www.chippy.tools/building-codes/us/ak/) - [Alabama](https://www.chippy.tools/building-codes/us/al/) - [Arkansas](https://www.chippy.tools/building-codes/us/ar/) - [Arizona](https://www.chippy.tools/building-codes/us/az/) - [California](https://www.chippy.tools/building-codes/us/ca/) - [Colorado](https://www.chippy.tools/building-codes/us/co/) - [Connecticut](https://www.chippy.tools/building-codes/us/ct/) - [Delaware](https://www.chippy.tools/building-codes/us/de/) - [Florida](https://www.chippy.tools/building-codes/us/fl/) - [Georgia](https://www.chippy.tools/building-codes/us/ga/) - [Hawaii](https://www.chippy.tools/building-codes/us/hi/) - [Iowa](https://www.chippy.tools/building-codes/us/ia/) - [Idaho](https://www.chippy.tools/building-codes/us/id/) - [Illinois](https://www.chippy.tools/building-codes/us/il/) - [Indiana](https://www.chippy.tools/building-codes/us/in/) - [Kansas](https://www.chippy.tools/building-codes/us/ks/) - [Kentucky](https://www.chippy.tools/building-codes/us/ky/) - [Louisiana](https://www.chippy.tools/building-codes/us/la/) - [Massachusetts](https://www.chippy.tools/building-codes/us/ma/) - [Maryland](https://www.chippy.tools/building-codes/us/md/) - [Maine](https://www.chippy.tools/building-codes/us/me/) - [Michigan](https://www.chippy.tools/building-codes/us/mi/) - [Minnesota](https://www.chippy.tools/building-codes/us/mn/) - [Missouri](https://www.chippy.tools/building-codes/us/mo/) - [Mississippi](https://www.chippy.tools/building-codes/us/ms/) - [Montana](https://www.chippy.tools/building-codes/us/mt/) - [North Carolina](https://www.chippy.tools/building-codes/us/nc/) - [North Dakota](https://www.chippy.tools/building-codes/us/nd/) - [Nebraska](https://www.chippy.tools/building-codes/us/ne/) - [New Hampshire](https://www.chippy.tools/building-codes/us/nh/) - [New Jersey](https://www.chippy.tools/building-codes/us/nj/) - [New Mexico](https://www.chippy.tools/building-codes/us/nm/) - [Nevada](https://www.chippy.tools/building-codes/us/nv/) - [New York](https://www.chippy.tools/building-codes/us/ny/) - [Ohio](https://www.chippy.tools/building-codes/us/oh/) - [Oklahoma](https://www.chippy.tools/building-codes/us/ok/) - [Oregon](https://www.chippy.tools/building-codes/us/or/) - [Pennsylvania](https://www.chippy.tools/building-codes/us/pa/) - [Rhode Island](https://www.chippy.tools/building-codes/us/ri/) - [South Carolina](https://www.chippy.tools/building-codes/us/sc/) - [South Dakota](https://www.chippy.tools/building-codes/us/sd/) - [Tennessee](https://www.chippy.tools/building-codes/us/tn/) - [Texas](https://www.chippy.tools/building-codes/us/tx/) - [Utah](https://www.chippy.tools/building-codes/us/ut/) - [Virginia](https://www.chippy.tools/building-codes/us/va/) - [Vermont](https://www.chippy.tools/building-codes/us/vt/) - [Washington](https://www.chippy.tools/building-codes/us/wa/) - [Wisconsin](https://www.chippy.tools/building-codes/us/wi/) - [West Virginia](https://www.chippy.tools/building-codes/us/wv/) - [Wyoming](https://www.chippy.tools/building-codes/us/wy/) - [District of Columbia](https://www.chippy.tools/building-codes/us/dc/) This page is general information for tradespeople and is not compliance, engineering or legal advice. Requirements are subject to state and territory variations and adoption timing. Always confirm requirements with your building certifier and relevant state authority. ## Page directory - [Alabama Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/al/index.md): Alabama's statewide residential code is still the 2015 IRC-based edition, with a newer one reportedly pending — the stair and guard figures follow the IRC baseline. - [Alaska Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ak/index.md): Alaska's new statewide minimum residential code took effect January 2026, based on the 2018 IRC — the stair and guard figures follow the IRC baseline. - [Arizona Building Codes: Local Adoption, No Statewide Residential Code](https://www.chippy.tools/building-codes/us/az/index.md): Arizona has no mandatory statewide residential code — cities and counties adopt and amend their own IRC edition, so stair and guard rules vary by jurisdiction. - [Arkansas Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ar/index.md): Arkansas runs a statewide residential code based on the 2021 IRC — the stair and guard figures follow the IRC baseline. - [California Residential Code: Stairs & the 42-inch Guard](https://www.chippy.tools/building-codes/us/ca/index.md): California's stair geometry matches the IRC, but it demands taller 42-inch guards — the signature CRC amendment. Here's what applies under the 2025 CRC. - [Colorado Building Codes: Local Adoption, No Statewide Residential Code](https://www.chippy.tools/building-codes/us/co/index.md): Colorado has no mandatory statewide residential building code — jurisdictions adopt and amend their own IRC edition, with only a statewide energy-code floor. - [Connecticut State Building Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ct/index.md): Connecticut runs its own state building code built around the 2021 IRC — the stair and guard figures follow the IRC baseline. - [DC Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/dc/index.md): Washington DC builds to the 2017 DC Construction Codes, based on the 2015 I-codes — the oldest base edition of any US jurisdiction we cover. Here's what applies. - [Delaware Building Codes: Local Adoption, No Statewide Residential Code](https://www.chippy.tools/building-codes/us/de/index.md): Delaware has no mandatory statewide residential code — counties and towns adopt their own IRC edition (e.g. Sussex County 2021, New Castle County 2018). - [Florida Building Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/fl/index.md): Florida runs the FBC Residential — its own IRC-based code — but its amendments are about wind, not stairs. The stair and guard figures match the IRC. - [Georgia State Minimum Standard Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ga/index.md): Georgia's new statewide residential code, based on the 2024 IRC, took effect January 2026 with Georgia amendments — the stair and guard figures follow the IRC baseline. - [Hawaii State Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/hi/index.md): Hawaii's state code sets a 2021 IRC baseline, but each of the four counties must adopt — and can amend — it within two years, so confirm your county's version. - [Idaho Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/id/index.md): Idaho runs a statewide residential code based on the 2018 IRC — the stair and guard figures follow the IRC baseline. - [Illinois Building Codes: Local Adoption, No Statewide Residential Edition](https://www.chippy.tools/building-codes/us/il/index.md): Illinois has no single statewide IRC edition — local jurisdictions adopt under a 2025 baseline law, and Chicago runs its own construction code entirely. - [Indiana Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/in/index.md): Indiana runs its own state-amended residential code based on the 2018 IRC — the stair and guard figures follow the IRC baseline. - [Iowa Building Codes: Local Option, No Statewide Residential Code](https://www.chippy.tools/building-codes/us/ia/index.md): Iowa's state code is based on the 2015 IRC, but adoption for new one- and two-family homes is a local option — jurisdictions can adopt a different code or none at all. - [IRC Stair & Guard Rules: Riser, Tread, Handrail, Guards](https://www.chippy.tools/building-codes/us/stairs/stair-and-barrier-requirements/index.md): The IRC numbers for a residential stair — 7¾ in max riser, 10 in min tread, 36 in guards — and the one thing every US builder must check first: which edition your state and town adopted. - [Kansas Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/ks/index.md): Kansas has no statewide residential code — it's home rule. Most major cities build to the 2018 IRC with local amendments. - [Kentucky Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ky/index.md): Kentucky's 2018 KRC is a confusing name — its 3rd Edition, effective 2024, is actually built on the 2015 IRC. Stair and guard figures follow the IRC baseline. - [Louisiana State Uniform Construction Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/la/index.md): Louisiana builds new one- and two-family homes to the 2021 IRC under the state uniform code. Stair and guard figures follow the IRC baseline. - [Maine Uniform Building and Energy Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/me/index.md): Maine's MUBEC sets a statewide standard on the 2021 IRC, but enforcement isn't mandatory in every small town. Stair and guard figures follow the IRC baseline. - [Maryland Building Performance Standards: Stairs & Guards](https://www.chippy.tools/building-codes/us/md/index.md): Maryland's MBPS sets a single statewide standard on the 2021 IRC, but local jurisdictions can layer their own amendments on top. - [Massachusetts Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ma/index.md): Massachusetts runs its own nth-edition-numbered code — the 10th Edition, built on the 2021 IRC. Stair and guard figures follow the IRC baseline. - [Michigan Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/mi/index.md): Michigan's 2021 code is tied up in litigation and its implementation was paused by a court order — the current edition is genuinely unsettled. Verify before relying on it. - [Minnesota Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/mn/index.md): Minnesota's statewide residential code adopts the 2018 IRC by reference. Stair and guard figures follow the IRC baseline. - [Mississippi Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/ms/index.md): Mississippi sets a discretionary statewide minimum of the 2021 IRC, but adoption is left to local jurisdictions, who pick from the three most recent approved editions. - [Missouri Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/mo/index.md): Missouri has no statewide residential code — it's home rule. Kansas City and St. Louis maintain their own amended editions; most areas commonly use IRC 2015–2018. - [Montana Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/mt/index.md): Montana adopts the 2021 IRC by reference as a mandatory statewide code. Stair and guard figures follow the IRC baseline. - [Nebraska State Building Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ne/index.md): Nebraska's state code is enforced mainly at the local level, with the state edition acting as a backstop where a locality hasn't adopted its own. Figures follow the IRC baseline. - [Nevada Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/nv/index.md): Nevada has no single statewide residential code — the IRC edition and any amendments are set locally, and Clark County maintains its own amendments. Confirm before relying on any figure. - [New Hampshire State Building Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/nh/index.md): New Hampshire builds to the 2021 IRC statewide, with a 2024 IRC edition due to enter a concurrency window from 1 July 2026 — confirm which edition your building department is currently accepting. - [New Jersey Uniform Construction Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/nj/index.md): New Jersey runs its own Uniform Construction Code, with houses covered by a New Jersey edition of the 2021 IRC. The stair and guard figures follow the IRC baseline. - [New Mexico Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/nm/index.md): New Mexico's own-named residential code closely follows the 2021 IRC. Stair and guard figures follow the IRC baseline. - [New York Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ny/index.md): New York runs its own Residential Code of New York State, now updating to a 2025 edition — but New York City runs an entirely separate construction code that this page doesn't cover. - [North Carolina Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/nc/index.md): North Carolina runs its own code cycle — the 2018 NCRC is still current, with the next edition delayed since early 2025. Stair figures follow the IRC baseline. - [North Dakota State Building Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/nd/index.md): North Dakota's state code is built on the 2024 IRC, but outside state and school buildings, enforcement is a local opt-in choice — here's what applies and where. - [Oklahoma Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ok/index.md): Oklahoma's statewide minimum is a 2018 IRC-based code due to hand over to the 2024 IRC on 14 September 2026 — check current status before relying on either edition. - [Oregon Residential Specialty Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/or/index.md): Oregon runs its own Residential Specialty Code statewide, and — unusually — allows no local amendments at all. Stair and guard figures follow the IRC baseline. - [Pennsylvania Uniform Construction Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/pa/index.md): Pennsylvania's statewide UCC moved to the 2021 IRC for new permit applications from 1 January 2026, with prior permits still under the 2018 IRC — confirm which applies to your permit. - [Residential Code of Ohio: Stairs & Guards](https://www.chippy.tools/building-codes/us/oh/index.md): Ohio runs its own Residential Code of Ohio, based on the 2018 IRC — but enforcement for 1-3 family homes is a local option, not a state mandate. Confirm before relying on it. - [Rhode Island SBC-2 Dwelling Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ri/index.md): Rhode Island runs its own-numbered SBC-2 code for one- and two-family homes, directly based on the IRC. Confirm the current edition before relying on these figures. - [Shower & Tub Wall Finish (IRC R307.2)](https://www.chippy.tools/building-codes/us/wet-areas/waterproofing-requirements/index.md): The IRC's 72-inch rule for nonabsorbent shower and tub walls, the backer board that has to sit behind the tile, and why the code stops short of a full waterproofing spec. - [South Carolina Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/sc/index.md): South Carolina builds to the 2018 South Carolina Residential Code, with a newer edition in the adoption pipeline. Here's what applies, and what to confirm. - [South Dakota Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/sd/index.md): South Dakota has no statewide residential building code — the IRC applies only where your city or county has adopted it. Here's how to check. - [Tennessee Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/tn/index.md): Tennessee sets the 2018 Residential Code as a statewide minimum, but plenty of cities and counties build to something newer. Here's what applies. - [Texas Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/tx/index.md): Texas sets only a 2012 IRC statewide floor — the real answer is set by your city, which usually builds to something newer. Here's how it actually works. - [US Footing Sizes & Frost Depth (IRC R403)](https://www.chippy.tools/building-codes/us/footings/footing-sizes-and-depth/index.md): The IRC's minimum footing size, the 12-inch depth rule, and why your frost line and footing width come off local tables, not a national number. - [US Minimum Ceiling Heights (IRC R305)](https://www.chippy.tools/building-codes/us/rooms/minimum-ceiling-heights/index.md): The IRC's 7-foot rule for habitable rooms and the 6-foot-8 drop for bathrooms — room by room, with the sloped-ceiling exceptions. - [US Ramp Slopes (IRC R311.8)](https://www.chippy.tools/building-codes/us/ramps/ramp-gradients/index.md): The IRC's 1:12 maximum for an egress ramp, the steeper 1:8 allowed elsewhere, landings and when a handrail is required. - [Utah State Construction Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/ut/index.md): Utah builds to a statewide 2021 IRC-based code. Here's what applies, and why it's worth confirming the current edition before you rely on it. - [Vermont Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/vt/index.md): Vermont has no statewide residential building code for owner-occupied homes — only its energy standard applies statewide. Here's how to find what governs your project. - [Virginia Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/va/index.md): Virginia runs its own Uniform Statewide Building Code — the USBC — currently built on the 2021 IRC. Here's what applies to a house stair. - [Washington State Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/wa/index.md): Washington runs its own state code on its own adoption cycle — currently built on the 2021 IRC. Here's what applies to a house stair. - [West Virginia Residential Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/wv/index.md): West Virginia's statewide code is IRC 2018-based, but enforcement needs local opt-in — so it isn't automatically enforced everywhere. Here's what applies. - [Wisconsin Uniform Dwelling Code: Stairs & Guards](https://www.chippy.tools/building-codes/us/wi/index.md): Wisconsin doesn't adopt the IRC at all — it runs its own Uniform Dwelling Code, with its own stair, guard and footing numbering. Here's what applies. - [Wyoming Building Codes: Stairs & Guards](https://www.chippy.tools/building-codes/us/wy/index.md): Wyoming has no confirmed statewide residential code edition — adoption is local. Here's how to find what actually applies to your project. ## Other languages - [es](https://www.chippy.tools/es/building-codes/us/index.md)