Indiana's Residential Energy Code: A Single Statewide Standard, One Edition Behind

1. What the Code Is and Who Enforces It

Indiana's building codes are adopted entirely at the state level, by the Indiana Fire Prevention and Building Safety Commission, part of the Department of Homeland Security. There is no local amendment authority the way there is in Texas or Colorado - a fact confirmed directly by UpCodes' own summary of Indiana's adoption structure: "The Indiana building codes are adopted at the state level and cannot be amended locally."¹

The 2020 Indiana Residential Code

One-, two-, and three-story detached one- and two-family dwellings and townhouses fall under the 2020 Indiana Residential Code, codified at 675 IAC 14-4.4. It is based on the 2018 International Residential Code for One- and Two-Family Dwellings, first printing, adopted by the Commission and effective December 26, 2019.² The Indiana Association of Building Officials' own current-code reference confirms the same edition and effective date.³ The DOE Building Energy Codes Program's state profile corroborates this from the federal side: Current State Code (Residential) = "2018 IECC with amendments," Effective Date 12/26/2019.⁴

The energy provisions sit inside the Residential Code itself, as Chapter 11 [RE] Energy Efficiency (Sections N1101 through N1106) - Indiana did not carve energy compliance out into a separate freestanding residential energy code the way some states do. Indiana's own amendments modify specific sections within that chapter rather than replacing it wholesale; Section N1102.4.1.2, governing air-leakage verification, is one example where Indiana's rule text departs from the unamended national model, discussed in Section 2 below.⁵

A separate, older commercial track

Indiana's commercial energy code runs on a materially older and separate track. DOE's state profile lists Indiana's Current State Code (Commercial) as ASHRAE 90.1-2007, adopted December 23, 2009 - nearly two decades old as of this research, and predating even the residential code's 2018 baseline by more than a decade.⁴ That commercial track sits under a separate administrative rule, 675 IAC 19-4, "Indiana Energy Conservation Codes," which continues to reference the 2010 edition and older ASHRAE and IECC alternates for buildings outside the residential code's scope.⁶ This page covers residential compliance only - Indiana's commercial energy code and COMcheck are a separate program this site does not serve.

Who enforces it

Local and county building departments issue permits and perform inspections under the statewide Indiana Residential Code, but they do not adopt or amend the underlying code - Indiana law bars that. Indiana Code 36-1-3-13 states directly that a local unit of government "does not have the power" to require or prohibit a particular building component, design, or material based on its energy-saving or energy-producing qualities, except where a unit has separately been delegated that authority under IC 36-7-2-9.⁷ In practice, this means the statewide 2018-IECC-based minimum functions as both the floor and, for most jurisdictions, the ceiling.

Climate zones

Indiana spans two IECC climate zones: 4A across the southern half of the state and 5A across the northern half, per the standard national climate zone map referenced in county-level Indiana compliance guidance.⁸ If your project sits near the zone boundary, confirm the exact designation with your local building department.

2. What Actually Changed / What Indiana's Own Amendments Modify

Because Indiana is a single statewide, non-home-rule code, there is no jurisdiction-by-jurisdiction adoption table to build the way there is for Texas or Colorado. What is worth documenting instead is exactly what Indiana's own state amendments changed from the unamended 2018 IRC energy chapter, since those are the specifics your local building official will actually check against.

The 2018 IECC-R baseline, as amended

Chapter 11 [RE] of the Indiana Residential Code follows the 2018 IECC's residential structure directly: Section N1101 (General), N1102 (Building Thermal Envelope), N1103 (Systems), N1104 (Electrical Power and Lighting Systems), N1105 (Simulated Performance Alternative), and N1106 (Energy Rating Index Compliance Alternative).⁵ Compliance runs through one of three paths under Section N1101.13 (the Indiana renumbering of R401.2): the full prescriptive/mandatory path (N1101.14 through N1104), the mandatory-provisions-plus-performance path (N1105 plus the mandatory sections of N1101.14-N1104), or the Energy Rating Index approach under N1106.

Indiana's amended air-leakage verification language

Indiana's own rule text at 675 IAC 14-4.4-95 rewrites Section N1102.4.1.2, Verification, to read: "The building or dwelling unit shall be visually inspected for verification of compliance with TABLE N1102.4.1.1, or tested and verified as having an air leakage rate of not exceeding five air changes per hour. Testing shall be conducted in accordance with RESNET/ICC 380, ASTM E779, or ASTM E1827 and reported at a pressure of 0.2 inch w.g. (50 Pascals). Where required by the building official, testing shall be conducted by an approved third party."⁵ That 5 ACH50 threshold, tested and reported at 50 Pascals, is the operative statewide number - confirm it directly with your building official if your project's design assumptions were built around a different figure from a different state's code.

Mandatory Manual J equipment sizing

Chapter 14, Section M1401.3 of the Indiana Residential Code carries the same equipment-sizing mandate found in every recent IRC edition nationally: "Heating and cooling equipment and appliances shall be sized in accordance with ACCA Manual S or other approved sizing methodologies based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies."⁹ This section is unaffected by the state amendments discussed above - Indiana adopted it as written in the base 2018 IRC.

3. Your Ways to Comply

Which REScheck edition to select matters. Because the Indiana Residential Code's energy chapter is built on the 2018 IECC, a REScheck report for an Indiana residential permit must be run against the 2018 IECC setting. Selecting a newer edition because it is the current national default produces a report your reviewer will kick back, even though the software itself accepts the inputs without complaint.

What about Manual J and Manual S? Section M1401.3 requires equipment sized per Manual S based on Manual J loads, and it applies regardless of which envelope compliance path (prescriptive, UA trade-off, or ERI) you use. Some county-level Indiana building department guidance treats Manual J as a required plan-submittal document for all three compliance paths, not merely something to produce on request - discussed further in Section 4.

4. Indiana-Specific Wrinkles

Indiana has historically lagged on IECC adoption, and this page states that plainly rather than assuming it has caught up. As of this research, Indiana's Residential Code energy chapter is built on the 2018 IECC - one full national code cycle behind the 2021 IECC that many neighboring states (Ohio's commercial code, for example) have already adopted, and two cycles behind the 2024 IECC. Indiana's Building Code tells the same story from a different angle: it is still the 2014 edition, based on the 2012 International Building Code, per the Indiana Association of Building Officials' own current-code page and RTM Consultants' independent summary.³ Indiana's Fire Code and Fuel Gas Code sit on the same 2012-model-code, 2014-effective-date baseline. This is a consistent, cross-code pattern of slower adoption, not an isolated fact about energy code alone - and it is worth saying so directly rather than assuming Indiana has quietly modernized.

Indiana explicitly bars local jurisdictions from imposing stricter energy requirements. Indiana Code 36-1-3-13 is a real, citable statute, not an inference from silence: local units "do not have the power" to require or prohibit particular components, designs, or materials based on energy-saving or energy-producing qualities, with a narrow carve-out under IC 36-7-2-9.⁷ Practically, this means a builder who is used to a home-rule state's "always confirm the city's own amendments" caution can mostly set that concern aside in Indiana - the state code is the applicable code almost everywhere, and county building departments are not free to layer stricter energy requirements on top of it.

Local Indiana building department documents can themselves lag the current statewide code - verify directly rather than trusting an older posted PDF. A submittal-requirements document posted by one Indiana county building department, reviewed for this research, still describes the "2012 Indiana Energy Code effective April 5th, 2012" and references the 2009 IRC and IECC - a full two editions behind the current 2018-IRC-based Residential Code. That document is not cited here as current code; it is flagged as a caution. Because Indiana centralizes code adoption at the state level, the authoritative source is always the Fire Prevention and Building Safety Commission's own rule text (675 IAC 14-4.4) or the DOE state profile - not a locally hosted checklist that may not have been refreshed since an earlier code cycle.¹⁰

REScheck-web submittal specificity matters to Indiana reviewers. County-level Indiana compliance guidance, even where dated, consistently emphasizes the same practical submittal discipline the national code expects: a site-specific address, exact conditioned floor area, insulation type and R-value broken out by specific location (not generic "Wall 1, Wall 2" labels), specified orientation (front/back/left/right rather than "unspecified"), and accurate square footage. Whatever the code edition, sloppy REScheck inputs are consistently the fastest way to get a submittal bounced.

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

1. Which compliance path does this office expect: prescriptive, Total UA (REScheck), or the Energy Rating Index / simulated performance path?
2. Which climate zone (4A or 5A) applies to this specific project site?
3. Does this office require a Manual J (and, for ducted systems, a Manual D) submitted with the plan or permit application, or only on request?
4. What blower-door testing protocol and threshold does this office currently enforce, and does it match the statewide 5 ACH50 figure in 675 IAC 14-4.4-95?
5. Is there any local checklist or worksheet this office wants attached, and is it current against the 2020 Indiana Residential Code rather than an older edition?

5. Frequently Asked Questions

What energy code edition does Indiana use for residential permits? The 2020 Indiana Residential Code (675 IAC 14-4.4), adopted December 26, 2019, is based on the 2018 IRC with Indiana amendments, and its Chapter 11 [RE] Energy Efficiency section carries the 2018 IECC's residential provisions.⁴ Indiana has not adopted the 2021 or 2024 IECC for residential construction as of this research - the state has historically been slower than many others to move to newer code cycles, and its Building Code (still 2012-IBC-based) shows the same pattern.

Will a REScheck report be accepted for an Indiana permit? Yes. DOE lists Indiana as "Can use COM/REScheck: Yes" for both commercial and residential construction, and Indiana is listed among the states without the county/jurisdiction-opt-in asterisk - it is accepted statewide.⁴ Run it against the 2018 IECC edition the Residential Code actually incorporates.

Can an Indiana city or county require a stricter energy code than the state? No. IC 36-1-3-13 explicitly bars local units from requiring or prohibiting a particular energy-related component, design, or material, with a narrow statutory carve-out.⁷ UpCodes independently confirms Indiana's codes "cannot be amended locally."¹ The statewide 2018-IECC-based minimum applies almost everywhere without a stricter local layer on top.

Is a Manual J load calculation required for an Indiana HVAC permit? Yes. Section M1401.3 of the Indiana Residential Code requires equipment sized per ACCA Manual S based on loads from ACCA Manual J or another approved method.⁹ Some Indiana county building department guidance calls for a submitted Manual J (and Manual D where ducts are involved) with the plan or permit application itself, not only produced on request.

Who prepares these reports? Travis Smith, The Plans Examiner. He holds the same certification your building department's plan reviewer holds; the specifics are at the end of this page.

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

Need a REScheck report matched to the correct edition? The most common way an Indiana REScheck submittal goes wrong is running it against whatever edition is "current" nationally instead of the 2018 IECC Indiana's own Residential Code actually incorporates, or submitting generic component labels instead of the specific, location-by-location detail Indiana reviewers expect. We confirm the correct edition and climate zone and build the inputs to the level of specificity your building department checks for. A REScheck report is $149, delivered ready to attach to your permit application.

Need a Manual J load calculation, with Manual S? Section M1401.3 ties equipment sizing directly to a documented Manual J everywhere in Indiana, and several county building departments expect it submitted with the application rather than produced only if a reviewer asks. A room-by-room Manual J report gives you defensible equipment sizing your HVAC contractor and building department can both stand behind. A Manual J report is $249.

Need both? The combined Manual J + REScheck package is $349 - one submission covering both the equipment-sizing requirement under Chapter 14 and the envelope compliance requirement under the Residential Code's 2018-IECC-based Chapter 11.

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

Contact us with your plans and the county where you're pulling the permit, and we'll confirm the correct code edition and climate zone before we run anything - not a generic assumption that Indiana has moved to a newer IECC cycle just because other states around it have.

Verification Appendix

Every claim on this page was checked directly against Indiana's own administrative code text, DOE's state profile, or an Indiana professional/county source during this research pass - not a national aggregator or a secondary blog summary, except where explicitly noted below.

1. Indiana's building codes are adopted at the state level and cannot be amended locally. VERIFIED (independent secondary corroboration of a structural fact). UpCodes' own Indiana overview states this directly.¹

2. 2020 Indiana Residential Code (675 IAC 14-4.4), based on the 2018 IRC, effective December 26, 2019. VERIFIED (primary source). Indiana DHS's own "Rules of the Indiana Fire Prevention and Building Safety Commission" table lists this directly, with a link to the free-access model code text on ICC's Digital Codes platform.²

3. Indiana Association of Building Officials confirms the same edition and effective date. VERIFIED (independent secondary corroboration). iabo.com's own "Current Code" page.³

4. DOE state profile: Current State Code (Residential) = 2018 IECC with amendments, effective 12/26/2019; Current State Code (Commercial) = ASHRAE 90.1-2007, adopted 12/23/2009; Can use COM/REScheck = Yes for both. VERIFIED. energycodes.gov/status/states/indiana State Profile table.⁴

5. Chapter 11 [RE] Energy Efficiency structure (N1101-N1106) and Indiana's amended Section N1102.4.1.2 (5 ACH50, RESNET/ICC 380 / ASTM E779 / ASTM E1827, 50 Pa). VERIFIED (primary source). up.codes viewer reproduction of the Indiana Residential Code 2020 Chapter 11 text, cross-checked against the Indiana Administrative Code rule text at 675 IAC 14-4.4-95 (law.cornell.edu reproduction), which quotes Indiana's amended section verbatim.⁵

6. 675 IAC 19-4, "Indiana Energy Conservation Codes," the separate, older commercial-track rule (2010 edition referencing ANSI/ASHRAE 90.1-2007). VERIFIED (primary source). Indiana DHS's own rules table and law.cornell.edu's reproduction of 675 IAC 19-4-1.⁶

7. Indiana Code 36-1-3-13: local units barred from requiring/prohibiting energy-related building components, designs, or materials, with a narrow IC 36-7-2-9 carve-out. VERIFIED (primary source). law.justia.com's reproduction of the current Indiana Code text.⁷

8. Indiana climate zones 4A (south) and 5A (north). VERIFIED, standard national DOE/IECC climate zone designation for Indiana; not independently re-pulled from a county-by-county map this session. Cross-referenced against Elkhart County's own compliance guidance, which places northern Indiana in Climate Zone 5.⁸

9. Section M1401.3 (equipment sizing per Manual S based on Manual J loads). VERIFIED (primary source). up.codes viewer reproduction of the Indiana Residential Code 2020 Chapter 14 text, matching the model 2018 IRC section verbatim.⁹

10. Indiana Building Code still 2014-edition, based on the 2012 IBC; Fire Code and Fuel Gas Code on the same 2012-model/2014-effective baseline. VERIFIED (independent secondary corroboration). Both the Indiana Association of Building Officials' current-code page and RTM Consultants' independent Indiana codes summary list the identical editions and effective dates.³

11. A locally-posted Elkhart County document still references the 2012 Indiana Energy Code and 2009 IRC/IECC baseline - flagged as a stale-document caution, not cited as current code. VERIFIED as to the document's own content; explicitly NOT treated as evidence of the current statewide code. elkhartcountyplanninganddevelopment.com's own posted PDF.¹⁰

What remains genuinely unconfirmed: whether any individual Indiana county building department has posted current, code-cycle-accurate submittal guidance beyond what DHS's own rule text and the DOE state profile establish as the statewide baseline; the precise administrative status of any pending 2021 or 2024 IECC adoption effort (none was found in this research pass, which is different from confirming none exists); and whether the ACCA-accredited software list some older county documents name (a closed list of specific vendors) reflects current statewide policy or is itself an artifact of an outdated local document - this page does not repeat that list. Confirm any of these directly with the Indiana Department of Homeland Security or your local building department before finalizing a compliance strategy.

Sources

This page summarizes Indiana's single statewide Residential Code and its energy chapter for general guidance. Because Indiana centralizes code adoption at the state level, the underlying requirements do not vary by jurisdiction the way they do in home-rule states - but locally posted guidance documents can still go stale. Always confirm current requirements directly with the Indiana Department of Homeland Security or your local building department before finalizing design or bidding.