Utah's Residential Energy Code: One Statewide Code, Two Different Blower-Door Numbers

Before you submit your permit packet

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1. What the Code Is and Who Enforces It

Utah is a single-code state in the strictest sense on this site: the Legislature adopts one State Construction Code by statute, and no city, county, or town may adopt a different edition or different energy-code amendments than the state's. Utah Code 15A-1-102 defines the "State Construction Code" as the codes adopted under Title 15A Chapters 2 (base editions), 3 (statewide amendments), 4 (local amendments), and 6 - and Utah Code 15A-4-701, the chapter reserved for local IECC amendments, says only: "No local amendments to the IECC are adopted."¹ Chapter 4's Part 2 (local IRC amendments) contains exactly two jurisdiction-specific entries statewide - wood-shingle roofing rules for Park City and a wildfire ignition-resistant construction section for Sandy City - and neither touches energy, insulation, or HVAC sizing.² If you've read another state's page on this site, that's the opposite of Texas's home-rule patchwork or Colorado's jurisdiction-by-jurisdiction adoption calendar: in Utah, the energy-code text a permit applicant faces is identical whether the project is in Salt Lake City or a small unincorporated county.

Who adopts it, and how

Utah Code 15A-1-204 puts the adoption power squarely with the Legislature: "The Legislature shall adopt a State Construction Code by enacting legislation that adopts a nationally recognized construction code with any modifications," and that legislation "shall state that the legislation takes effect on the July 1 after the day on which the legislation is enacted, unless otherwise stated."³ The Uniform Building Code Commission (UBCC) - a 13-member board of contractors, architects, engineers, a building official, a fire official, and public members, appointed to staggered terms and administered by the Division of Professional Licensing (DOPL) within the Department of Commerce - reviews each new edition of the national model codes and reports its recommendations to the Legislature's Business and Labor Interim Committee before the Legislature acts.⁴ The Legislature then writes the specific amendments directly into statute, not into a separate administrative rule, which is why Utah's amendments read like bill language (strike a number, insert a number) rather than a rulemaking notice.

The code in force since July 1, 2026

Utah Code 15A-2-103, in the version currently in force (effective 7/1/2026, superseded 1/1/2027), incorporates by reference: the 2024 IBC (with Appendices C and J), the 2021 IRC (plus Appendix AQ), the 2024 IPC, the 2024 IMC, the 2024 IFGC, the 2023 NEC, the 2024 IECC, the 2024 IEBC, the HUD Code, and the residential provisions of the 2024 ISPSC, together with the statewide and local amendments in Chapters 3 and 4.⁵ This edition set was enacted by House Bill 65, "Construction Code Amendments" (2026 General Session, Chapter 47), sponsored by Rep. Thomas W. Peterson and Sen. Evan J. Vickers, with a special effective-date clause making the changes to 15A-2-103 and the related amendment sections take effect July 1, 2026.⁶ The U.S. Department of Energy's Building Energy Codes Program state profile - a federal tracking page, not the authoritative text - separately lists Utah's prior residential cycle ("2021 IECC with Amendments," effective 07/01/2024) as of its last update; that page had not yet caught up to the July 2026 transition to the 2024 IECC as of this research, which is exactly why this page cites Utah's own code text rather than the federal summary.⁷

One genuinely unusual feature of Utah's adoption: the IRC stayed at the 2021 edition while the IBC, IECC, IMC, IFGC, and IEBC all jumped straight to 2024. That split - a newer commercial/energy code cycle paired with an older residential structural code - is deliberate, not an oversight; it is written the same way in both the 7/1/2026 version and the already-enacted 1/1/2027 version of 15A-2-103.⁵

Who enforces it

Cities and counties issue permits and inspect construction through their own building departments, but Utah Code 15A-1-202 defines every one of them as a "compliance agency" or "local regulator" applying the same State Construction Code - there is no certification process by which a Utah city adopts a materially different energy standard the way a certified Montana jurisdiction can carry a slightly different administrative rule set.⁸ A "qualified building official" under Utah Code 15A-1-202(16) must hold at least six years of relevant experience, an active combination-inspector license under Utah Code 58-56-9, and 40 hours of management training or a certified-building-official credential - all against the single statewide code.⁸ In practice this means the reviewer's identity changes by jurisdiction, but the numbers on the page they're checking your submittal against do not.

Climate zones

Utah spans three IECC climate zones, and unlike most states covered on this site, the split runs by county, not by metro area. Per the IECC's own official Table C301.1 ("Climate Zones, Moisture Regimes, and Warm Humid Designations by State, County and Territory"), Utah's 29 counties break down as: Zone 3B - Washington County only; Zone 6B - Daggett, Duchesne, Morgan, Rich, Summit, Uintah, and Wasatch counties; and Zone 5B - every other county, including Salt Lake, Utah, Davis, Weber, Tooele, Cache, and the rest of the state.⁹ That three-way split matters for the amended IECC's own zone-based tables (Section 2 below), but it does not matter at all for the rewritten IRC energy chapter that governs most single-family construction - Utah wrote that chapter with a single statewide table and no climate-zone column, discussed next.

2. Two Documents, Two Numbers: What Utah Actually Amended

This is the section every other page on this site handles as "which jurisdiction adopted what." Utah's wrinkle is different: there is only one jurisdiction, but there are two separately amended documents that both claim to govern residential energy compliance, and they don't say the same thing.

Document one: the amended 2024 IECC (Utah Code 15A-3-701)

Utah Code 15A-3-701 opens: "The following is adopted as an amendment to the IECC to be applicable statewide," followed by 42 numbered paragraphs of edits.¹⁰ The residential-relevant changes include:

• Fenestration U-factor loosened to 0.32 in Climate Zones 3, 5, and 6 (Tables R402.1.2 and R402.1.3), up from the national code's 0.30, with the Zone 3 glazed-fenestration SHGC limit also loosened from 0.25 to 0.35.
• Ceiling and wall U-factors loosened across all three of Utah's zones - for example, Zone 6 ceiling U-factor moves from 0.024 to 0.026 and Zone 6 wood-frame wall U-factor moves from 0.045 to 0.060 in Table R402.1.2, with a parallel set of R-value equivalents loosened in Table R402.1.3 (Zone 6 ceiling R-value drops from 60 to 49, for instance).
• A single statewide air-leakage number replaces the national zone split. Section R402.4.1.3's national text sets 5.0 ACH50 for Climate Zones 0-2 and 3.0 ACH50 for Zones 3-8; Utah's amendment deletes both figures and inserts a single 4.0 ACH50 requirement across every zone, with the compliance-checklist exception threshold loosened from 0.28 to "5.0 air changes per hour or 0.30" CFM/sq ft.
• A named REScheck performance path anchored to 2012. A new Section R402.1.5.1 states: "Compliance with section N1102.1.5 (R402.1.5) may be satisfied using the software RESCheck 2012 Utah Energy Conservation Code... provided the following conditions are met: (a) In Climate Zone 5 and 6 the software result shall show 5% better than code; and (b) In Climate Zone 3, the software result shall show 5% better than code" using specified window inputs.
• Energy Rating Index targets loosened. Table R406.5's maximum ERI score moves from 51 to 65 in Zone 3, 55 to 69 in Zone 5, and 54 to 68 in Zone 6 - a materially easier HERS/ERI performance-path target than the national code's.
• Duct leakage and duct insulation renumbered and adjusted (Section N1103.3.6/R403.3.6): total post-construction leakage limits move to 6.0 CFM/100 sq ft with the air handler installed and 5.0 CFM/100 sq ft without.
• Equipment-sizing qualification requirement added. A new Section R403.7.1 requires anyone performing load calculations for equipment sizing to be "qualified by completing HVAC training from" ACCA education, a recognized educational institution, HVAC equipment manufacturer training, or "other recognized industry certification."
• Sections R404.1.1, R404.2, R404.3 (lighting equipment specifics) and R408 (whole-house mechanical ventilation credit) are deleted outright, and Section 405.11 automatic receptacle control - present in an earlier draft - was struck entirely from the enrolled bill.

Notably, no local amendments exist on top of this - Utah Code 15A-4-701 forecloses that possibility statewide, which is why this section, unlike the equivalent section on almost every other state page here, doesn't need a jurisdiction-by-jurisdiction table.

Document two: the rewritten IRC Chapter 11 (Utah Code 15A-3-203(3))

Here is the wrinkle that makes Utah genuinely different from every other state on this site. The International Residential Code governs detached one- and two-family dwellings and townhouses (the IRC's own long-standing scope statement, unchanged by Utah's amendments), and the IRC carries its own energy chapter - Chapter 11 - which is ordinarily near-identical in substance to the IECC's residential provisions, just cross-numbered (N1102.1.2 corresponds to R402.1.2, for example). Utah didn't amend that chapter piecemeal. Utah Code 15A-3-203(3) deletes the entire IRC Chapter 11 and replaces it with a new, shorter, Utah-specific chapter: "Chapter 11, Energy Efficiency (Revised)."¹¹

The rewritten chapter's residential-relevant content, quoted directly from the statute:

• R1101.3 Compliance Paths - prescriptive (R1101.3.1, meet the table below) or performance (R1101.3.2, REScheck or HERS).
• R1101.3.2 Performance Compliance - "compliance may be demonstrated using U.S. DOE REScheck, provided the proposed design achieves an overall envelope performance not less than 5% above the current Utah 2012 REScheck standard, as documented on the REScheck compliance certificate or achieve a HERs rating of 67 or better."
• R1102.2 table (single statewide table, no climate-zone column at all): above-grade walls R-21; ceilings/roof assemblies R-38; floors over unconditioned space R-30; conditioned basement walls R-10 continuous or R-13 cavity; windows and glazed doors maximum U-0.32; skylights maximum U-1.3; opaque doors minimum U-0.6.
• R1104 Duct System Testing and Insulation - leakage not to exceed 6.0 CFM/100 sq ft with the air handler installed at time of test, 5.0 CFM/100 sq ft if not installed; ducts outside conditioned space insulated to R-8 minimum (ducts buried beneath concrete floors exempted).
• R1105 Building Thermal Envelope Air Leakage Testing - maximum 5.0 ACH50 (or 0.25 CFM/sq ft) for single-family construction and 6.0 ACH50 (or 0.28 CFM/sq ft) for multifamily construction, tested per ASTM E779 or E1827 at 0.2 in. w.g. (50 Pa), with an alternative compliance checklist (Table R41105, an air-barrier and insulation installation checklist) available instead of a blower-door test.

That 5.0 ACH50 single-family number is not the same as the amended IECC's 4.0 ACH50 statewide number described above. Both are real, current, correctly-quoted Utah statutory text - they simply live in two different documents that both nominally cover residential construction. For a detached single-family home or townhouse (the large majority of what this site's customers build), the IRC's own Chapter 11 - with its 5.0 ACH50 threshold and its single flat R-value table - is the document your local building official is almost certainly checking against, because that is the document whose scope statement actually names detached one- and two-family dwellings and townhouses. The amended IECC's provisions remain the governing text for building types outside the IRC's scope, such as larger multifamily buildings and commercial construction. Confirm which document applies with your specific building official before finalizing an envelope design or scheduling a blower-door test - this is exactly the kind of question this page exists to help you ask correctly.

What's pending: nothing for energy, before January 1, 2027

The same 2026 legislative session that produced HB 65 also enacted a further amendment to Utah Code 15A-2-103, already on the books and effective January 1, 2027 (Chapter 386, 2026 General Session).⁶ Comparing that version against the 7/1/2026 version fetched for this page, the IBC, IRC, IPC, IMC, IFGC, NEC, IECC, IEBC, and ISPSC edition citations are word-for-word identical in both. The only substantive change in that transition is Subsection (2): the Wildland-Urban Interface Code moves from the 2006 edition to the 2024 edition. No residential energy-code edition change, and no change to either blower-door number described above, has an adoption date set beyond what is already in force.

3. Your Ways to Comply

Whichever of the two documents governs your project, the same three-path structure applies, because Utah built its rewritten IRC chapter around the same prescriptive/performance/ERI logic the IECC uses nationally:

Which REScheck edition to select. This is the question Utah's code text answers more directly than almost any other state's: both the rewritten IRC chapter and the amended IECC name the same benchmark by number - "the current Utah 2012 REScheck standard" and "RESCheck 2012 Utah Energy Conservation Code," respectively - with a 5% margin required on top of it. That is precisely why REScheck-Web's own supported-codes list carries a state-specific "Utah 2012" edition and no current-year Utah variant; we confirmed this directly inside the REScheck-Web application's own code-selection dropdown, which lists "Utah 2012" alongside the standard 2024/2021/2018 IECC options and no other Utah-specific entry.¹² In practice: run the project in REScheck-Web against the Utah 2012 state edition, confirm the compliance certificate shows at least 5% better than that standard (not merely 0% or "pass"), and keep the certificate with your permit submittal - a HERS rating of 67 or better satisfies the same requirement without REScheck at all. Washington County's own building-permit-documents page lists a REScheck submittal as a required document for new single-family and accessory dwelling permits, confirming REScheck is genuinely in use on real Utah residential permits today, not just a theoretical option.¹³

What about Manual J? Both amended documents carry the same requirement in parallel: the amended IECC's Section R403.7.1 and the amended IRC's Section M1401.3.1 both require equipment sizing to follow "sizing methodologies complying with" a qualifications section, and both qualifications sections are worded identically - the person performing the load calculation must be qualified through ACCA HVAC load-calculation education, a recognized educational institution, HVAC equipment manufacturer training, or other recognized industry certification.¹⁰¹¹ That sizing itself still runs through ACCA Manual S based on ACCA Manual J loads - the standard national mechanical-sizing structure - Utah's amendment adds the qualification requirement on top of it, not a different sizing method.

4. Utah-Specific Wrinkles

Two documents, two blower-door numbers, one house. This is the single most consequential fact on this page. A builder who reads only the amended IECC's 4.0 ACH50 figure and tests to that number on a detached single-family home may be testing to the wrong document's threshold - the IRC's own rewritten Chapter 11, which is what actually governs that building type, sets 5.0 ACH50. Ask your specific building official which document their office checks against before you schedule a blower-door test, not after.

The REScheck baseline is genuinely 2012, not a typo and not neglect. Utah's code text has anchored its REScheck performance path to a "Utah 2012" standard across at least three code cycles now (traceable in Uniform Building Code Commission meeting records discussing this same section back in 2023, with the required improvement percentage escalating over the years before settling at a flat 5%).¹⁴ That is why REScheck-Web ships a "Utah 2012" edition and not a current-year one - the state's own code text, not DOE's software team, is what fixed the baseline year.

No climate-zone column in the table that governs most single-family homes. Utah spans three IECC climate zones by county, but the rewritten IRC Chapter 11's prescriptive table (R1102.2) applies one flat set of R-values and U-factors statewide - R-21 walls, R-38 ceilings, R-30 floors, regardless of whether the project is in Washington County (Zone 3B) or Rich County (Zone 6B). The amended IECC's own tables still vary by zone, but again, that document mostly governs building types outside detached single-family and townhouse construction.

Every reviewing jurisdiction checks the same numbers. Because Utah Code 15A-4-701 forecloses local IECC amendments and the only two local IRC amendments on the books (Park City wood-shingle rules, Sandy City wildfire construction) don't touch energy, there is no "confirm your city's adopted edition" step in Utah the way there is in Texas, Colorado, or Georgia. What does vary by jurisdiction is only the office reviewing your plans and its permit process, not the energy-code numbers themselves.

Equipment-sizing qualification is a real, written statutory requirement, not boilerplate. Utah's amendment doesn't just require a Manual J calculation exist - it names four specific qualification routes for whoever performs it. Confirm with your building official what documentation of that qualification, if any, they expect attached to the permit submittal alongside the load calculation itself.

What to ask your local building department before you finalize a compliance strategy:

1. For this specific building (detached single-family, townhouse, or another residential type), is my plan reviewed against the amended IECC or against the rewritten IRC Chapter 11 - and which blower-door number, 4.0 or 5.0 ACH50, applies?
2. If I run REScheck, do you require the "Utah 2012" state edition specifically, and what documentation do you need showing the 5% margin over that baseline?
3. Do you require the Manual J load calculation submitted with the permit application, and what do you need to see regarding the preparer's qualification under Section 403.7.1/M1401.3.1?
4. Is a HERS rating of 67 or better an acceptable substitute for REScheck on this project, and do you need the HERS certificate at permit or at final inspection?
5. Does Table R41105's air-barrier and insulation checklist satisfy your office in place of a blower-door test, or do you require the test regardless?

5. Frequently Asked Questions

What is Utah's current residential energy code? Utah Code 15A-2-103 incorporates the 2024 IECC and the 2021 IRC by reference, effective statewide since July 1, 2026. Utah then amends both: Utah Code 15A-3-701 amends the IECC directly, and Utah Code 15A-3-203(3) replaces the IRC's own Chapter 11 with an entirely rewritten energy chapter. There are no local energy amendments anywhere in the state.

Why does Utah have two different blower-door numbers for the same house? Because the two amended documents were written separately. The amended IECC sets a single statewide 4.0 ACH50 limit at Section R402.4.1.3. The rewritten IRC Chapter 11, which is what actually governs most detached single-family homes and townhouses, sets 5.0 ACH50 for single-family construction and 6.0 ACH50 for multifamily at Section R1105. Confirm which document your building official uses before testing.

Will a REScheck report be accepted for a Utah permit? Yes - both documents build a REScheck path directly into the statute, anchored to a "Utah 2012" baseline with a 5% improvement margin required, or a HERS rating of 67 or better as an alternative. REScheck-Web's own state-specific edition list names "Utah 2012," matching that statutory anchor.

Is a Manual J load calculation required in Utah? Yes. Both amended documents require ACCA Manual S sizing based on ACCA Manual J loads, prepared by someone qualified through ACCA education, a recognized educational institution, manufacturer training, or other recognized industry certification.

Is Utah about to change its energy code again? Not for energy. A further amendment to Utah Code 15A-2-103 is already enacted and takes effect January 1, 2027, but the IECC and IRC edition citations are identical to the version in force since July 1, 2026 - the only change in that transition is the Wildland-Urban Interface Code edition.

6. Get It Right the First Time - Before Plan Review Sends It Back

Need a REScheck report matched to the document your city is actually checking? The most consequential Utah-specific mistake isn't picking the wrong jurisdiction - every jurisdiction checks the same numbers - it's running REScheck against the wrong baseline or assuming a single blower-door target when your project's building type puts it under a different Utah-amended document than you expected. We confirm with you which document applies to your specific project and run REScheck against the Utah 2012 state edition with the required 5% margin, or confirm a HERS 67+ rating already covers it. A REScheck report is $149, delivered ready to attach to your permit application.

Need a Manual J load calculation? Utah's amendment requires equipment sizing to travel with a documented qualification for whoever performed the load calculation - not just the calculation itself. A room-by-room Manual J report gives your HVAC contractor and building department defensible, documented equipment sizing they can both stand behind. A Manual J report is $249 for homes up to 3,000 sq ft.

Need both? The combined Manual J + REScheck package is $349 - one submission covering equipment sizing and the envelope/compliance requirement, matched to whichever of Utah's two amended documents applies to your building.

Already been rejected? If your jurisdiction has already sent the report back, we work from the correction notice itself - see REScheck correction and resubmittal or Manual J correction and resubmittal.

Every report comes with the same guarantee: accepted by your building department, or we revise it free until it clears.

Adding a heat pump or replacing existing equipment? See our heat pump changeout Manual J guide for when a load calculation is expected on an equipment swap, not just new construction.

Building an ADU? See our Manual J for ADU guide for what that calculation needs to cover, and confirm with your city which of Utah's two energy documents applies to your accessory unit.

Installing a ductless mini-split? Our mini-split Manual J and permit requirements guide covers sizing documentation for ductless systems specifically.

Contact us with your plans and the city or county where you're pulling the permit, and we'll confirm whether your project falls under the amended IECC or the rewritten IRC Chapter 11, which blower-door number applies, and which REScheck edition to run.

Verification Appendix

Every claim on this page was checked directly against Utah's own published code text on le.utah.gov, the enacting legislation, or a jurisdiction's own document during this research pass - not a national aggregator or a secondary blog summary, except where explicitly noted below. The U.S. DOE state profile is cited once, below, as a corroborating source only, and this page notes where it disagrees with Utah's own text.

1. Utah Code 15A-4-701 ("No local amendments to the IECC are adopted") and Chapter 4 Part 2 (only Park City and Sandy City local IRC amendments, neither touching energy). VERIFIED (primary source). le.utah.gov/xcode/Title15A/Chapter4/15A-4-S701.html and le.utah.gov/xcode/Title15A/Chapter4/15A-4-P2.html, fetched directly.

2. Utah Code 15A-4-206 (Park City wood-shingle roofing amendment) and 15A-4-207 (Sandy City wildfire ignition-resistant construction amendment). VERIFIED (primary source). le.utah.gov/xcode/Title15A/Chapter4/15A-4-S206.html and 15A-4-S207.html, fetched and read in full; neither amendment references energy, insulation, or HVAC provisions.

3. Utah Code 15A-1-204 (Legislature's adoption authority; commission review and reporting process). VERIFIED (primary source). le.utah.gov/xcode/Title15A/Chapter1/15A-1-S204.html, fetched directly.

4. Uniform Building Code Commission membership and administration under DOPL. VERIFIED (primary source). commerce.utah.gov/dopl/uniform-building-codes/uniform-building-code-commission, the Division of Professional Licensing's own commission roster page, fetched directly.

5. Utah Code 15A-2-103, version effective 7/1/2026 (superseded 1/1/2027): full list of incorporated construction codes, including the 2024 IECC and 2021 IRC. VERIFIED (primary source). le.utah.gov/xcode/Title15A/Chapter2/15A-2-S103.html, fetched directly (the site blocks non-browser requests; content was retrieved with a live browser session). Cross-checked against the future version effective 1/1/2027 (same URL, "Effective 1/1/2027" tab) to confirm the IECC/IRC citations are identical in both.

6. H.B. 65, "Construction Code Amendments," 2026 General Session (Chapter 47), sponsor, effective-date clause (July 1, 2026), and the amendment to 15A-2-103 changing the IBC/IPC/IMC/IFGC/IECC/IEBC editions to 2024 while leaving the IRC at 2021. VERIFIED (primary source). le.utah.gov/~2026/bills/static/HB0065.html (bill status page) and le.utah.gov/Session/2026/bills/enrolled/HB0065.pdf (enrolled bill text), both fetched directly.

7. U.S. DOE Building Energy Codes Program state profile for Utah, cited as a corroborating, non-authoritative federal summary; noted as lagging Utah's own July 2026 transition to the 2024 IECC. CORROBORATING SOURCE ONLY, not primary. energycodes.gov/status/states/utah, fetched directly.

8. Utah Code 15A-1-102 (definition of "State Construction Code" spanning Chapters 2-4 and 6) and 15A-1-202 (definitions: compliance agency, local regulator, qualified building official). VERIFIED (primary source). le.utah.gov/xcode/Title15A/Chapter1/15A-1-S102.html and 15A-1-S202.html, fetched directly.

9. Utah's climate zones by county (3B Washington; 6B Daggett, Duchesne, Morgan, Rich, Summit, Uintah, Wasatch; 5B all others), per the IECC's own official Table C301.1. VERIFIED (primary source, code text). codes.iccsafe.org/content/UTECC2021P1 (2021 Utah State Energy Conservation Code, hosted by ICC), Table C301.1 fetched and read directly, cross-checked against the same table's treatment of neighboring states for consistency.

10. Utah Code 15A-3-701 (statewide amendments to the IECC): fenestration/wall/ceiling U-factor and R-value changes, the single statewide 4.0 ACH50 air-leakage amendment to Section R402.4.1.3, the Section R402.1.5.1 "RESCheck 2012 Utah Energy Conservation Code" performance path, Table R406.5 ERI target changes, duct leakage figures, and the Section R403.7.1 equipment-sizing qualification requirement. VERIFIED (primary source, full statutory text). le.utah.gov/xcode/Title15A/Chapter3/15A-3-S701.html, fetched and read in full (19,223 characters, all 42 numbered amendment paragraphs).

11. Utah Code 15A-3-203 (statewide amendments to IRC Chapters 6-15): the complete replacement of IRC Chapter 11 with "Chapter 11, Energy Efficiency (Revised)" including Sections R1101.3.2 (REScheck/HERS performance path, "Utah 2012" baseline, HERS 67), R1102.2 (single statewide prescriptive table), R1104 (duct leakage/insulation), R1105 (5.0 ACH50 single-family / 6.0 ACH50 multifamily air-leakage testing), and the amended IRC Section M1401.3/M1401.3.1 equipment-sizing qualification requirement. VERIFIED (primary source, full statutory text). le.utah.gov/xcode/Title15A/Chapter3/15A-3-S203.html, fetched and read in full (10,482 characters). Cross-checked against the enrolled H.B. 65 text (le.utah.gov/Session/2026/bills/enrolled/HB0065.pdf), which shows the same Chapter 11 replacement language with strikethrough/insert formatting confirming what changed from the prior cycle.

12. REScheck-Web's supported state-specific code list includes a "Utah 2012" edition and no current-year Utah-specific edition, alongside the standard national 2024/2021/2018/2015/2012/2009 IECC options. VERIFIED (primary source, direct application observation). Observed directly inside the REScheck-Web application (energycode.pnl.gov/REScheckWeb, DOE's own compliance software) New Project code-selection dropdown during this research session.

13. Washington County, Utah requires a REScheck submittal ("RESCheck (International Energy Conservation Code (IECC) COMPLIANCE)") as part of its building permit document checklist for new single-family and accessory dwelling permits. VERIFIED (primary source). washco.utah.gov/departments/community-development/building-permit-documents, the county's own Community Development Department page, fetched directly.

14. The "Utah 2012" REScheck performance-path baseline traces back at least to the prior code cycle's identical statutory language, discussed in Uniform Building Code Commission meeting minutes. VERIFIED (primary source, historical committee record). A UBCC public meeting record (utah.gov/pmn, meeting document ID 1060992) reproducing the prior cycle's Section 701 text with the same "RESCheck 2012 Utah Energy Conservation Code" language and an earlier, escalating percentage schedule (3%/4%/5% by year) that was later fixed to a flat 5% in the current cycle - confirming this is a longstanding, deliberate Utah policy choice carried across code cycles, not a drafting error.

15. Utah Code 58-56-9 (combination inspector licensure) and the "qualified building official" definition's cross-reference to it. VERIFIED as a stable, cross-referenced statutory citation appearing directly in the text of Utah Code 15A-1-202(16) fetched for citation 8 above; not independently re-pulled as its own section for this research pass.

What remains genuinely unconfirmed: which of the two amended documents (IECC vs. rewritten IRC Chapter 11) a specific Utah building official's office applies to a given multifamily or mixed-use residential project sitting near the boundary of the IRC's own scope statement (three stories, separate means of egress); the precise HERS-rating software and provider a given Utah HERS rater uses to certify the "67 or better" figure; and whether any individual Utah city or county has published its own guidance resolving the two-document question described in Section 2. Confirm any of these directly with the relevant building department before finalizing a compliance strategy.

Sources

This page summarizes Utah's statewide residential energy code for general guidance. Because Utah amended two separate documents with two different air-leakage numbers, confirm which document and which number apply to your specific project and jurisdiction before finalizing design, bidding, or scheduling a blower-door test.