College Station TX Energy Code Multifamily: 2024 IECC, Local Amendments, and When to Study First

If you are building multifamily inside the City of College Station, Texas, you are on the 2024 International Energy Conservation Code with local amendments, in effect since January 1, 2026. The City Council adopted the 2024 International Codes and the 2023 National Electrical Code on November 13, 2025 (listed as Ordinance 4646 in the City's code adoption history), replacing the 2021 codes that had applied since June 1, 2022. That puts College Station with Irving, Frisco, Plano, and McKinney on the 2024 IECC, while Dallas, Arlington, Denton, Grand Prairie, Houston, and San Antonio are still on the 2021 edition. With Texas A&M in town, much of College Station's multifamily is student housing, and Bryan sits right next door with its own code adoption, so check which city the permit address is in before anyone prices a package.

This page is the College Station Energy Code door for multifamily developers. For the statewide Texas commercial code path (the 2015 IECC floor, ASHRAE pairings, and why mid-rise is not HERS-first), see ASHRAE COMcheck Texas multifamily. For the Texas study door, see energy code feasibility study Texas. Other Texas city doors already live: Houston Energy Code multifamily, Austin Energy Code multifamily, Dallas Energy Code multifamily, San Antonio Energy Code multifamily, Fort Worth Energy Code multifamily, El Paso Energy Code multifamily, Corpus Christi Energy Code multifamily, Arlington Energy Code multifamily, Plano Energy Code multifamily, McKinney Energy Code multifamily, Frisco Energy Code multifamily, Denton Energy Code multifamily, Irving Energy Code multifamily, and Grand Prairie Energy Code multifamily. Program, testing, and modeling context: ENERGY STAR Multifamily New Construction, blower door testing for multifamily buildings, and multifamily energy modeling.

What Code Applies in College Station Right Now

Per the City of College Station Building Codes page and the adopted ordinance (primary sources; confirm with the City before you file):

• The City's Building Codes page lists the 2024 IBC, IRC, IPC, IMC, IFGC, IECC, IPMC, IFC, IEBC, and ISPSC, the 2024 NFPA 101 Life Safety Code, and the 2023 NEC, all in effect January 1, 2026, with local amendments posted for each code.
• The same page states that energy conservation design requires 2024 IECC COMcheck compliance reports for multi-family and commercial building permits. Plan for a COMcheck in the permit set, not as an afterthought.
• The City's code adoption history lists the 2024 International Codes and 2023 NEC as adopted November 13, 2025, effective January 1, 2026, Ordinance 4646. The 2021 codes before them took effect June 1, 2022 (Ordinance 4352).
• The ordinance amends Chapter 103, "Buildings and Building Regulations," Article III, "Technical Codes," of the Code of Ordinances. Section 103-139 carries the energy code amendments. The Construction Board of Adjustments and Appeals recommended the package unanimously on October 28, 2025, and the staff summary lists 11 IECC amendments.

College Station is in Brazos County, climate zone 2A (hot, humid), the same zone as Houston, Austin, San Antonio, and Corpus Christi, and one zone warmer than Dallas-Fort Worth. A climate zone 3A package from Irving, Frisco, or Plano is on the same edition but the wrong zone, so rerun it rather than copy it.

What College Station's Local Amendments Change in the 2024 IECC

The City's 2024 IECC amendments that matter most for apartment projects:

• Commercial envelope air leakage exception (C402.6). The amendment adds an exception: the thermal envelope air leakage is considered acceptable when the items in Table R402.5.1.1 that apply to the method of construction are field verified. Where the code official requires it, an approved third party, independent from the installer, inspects and approves the envelope and insulation installation.
• Residential air leakage testing exception (R402.5.1.2). The same field verification of the Table R402.5.1.1 items is accepted for building envelope tightness and insulation installation, again with an independent third party where the code official requires one.
• Duct testing exception (R403.3.7). Duct tightness is considered acceptable when listed sealing details are field verified, including UL listed mastic or at least two wraps of UL 181 listed tape at core to collar connections, mechanical clamps, and 4 inch metal sleeves at splices.
• Ducts outside conditioned space (R403.3.3). Supply and return ducts in unconditioned spaces may use R-6 insulation when paired with an air conditioner of at least SEER 16.
• Electric resistance heat (R403.14, added). Electric resistance heat may be the primary heating source for residential use not exceeding 500 square feet. That matters for studio and micro-unit layouts.
• Interior lighting controls (R404.2) deleted, and on-site sealing of electrical and communication boxes is accepted with approved sealants (R402.5.5).
• Verification of the ERI path (R406.6). The code official may require that R406 compliance be verified by an approved third party.
• Administrative changes. References to the ICC Electrical Code mean the NEC as adopted by the City, the IECC appeals sections (C109 and R109) are deleted, and the residential certificate (R401.3) is rewritten to list heating, cooling, and water heating equipment types and efficiencies.

The amendments do not delete the R408 additional efficiency options. The City's staff summary points out that the 2024 edition offers more than 50 R408 design options, so plan which credits you will use on the residential provisions.

Residential vs Commercial Split for Multifamily

The 2024 IECC draws the line by building type and height. Group R-2, R-3, and R-4 buildings three stories or less above grade plane fall under the residential provisions. Taller apartment buildings, and the nonresidential portions of any building, fall under the commercial provisions, where the 2024 IECC commercial chapter or its ASHRAE 90.1-2022 alternative applies.

• Mid-rise, podium, and mixed-use projects. Retail, amenity, lobby, corridor, and parking areas follow commercial documentation, and the City expects a 2024 IECC COMcheck with the multifamily permit. Ask the Building Official early how the C402.6 field verification exception will be applied to dwelling unit enclosures before you drop blower door testing from the budget.
• Garden-style, student housing, and townhome projects. Three stories or less usually lands on the residential provisions, where the local testing exceptions, the R-6 duct option with SEER 16 equipment, the 500 square foot electric resistance allowance, and the R408 credit menu can all change which package is cheapest.

Proof From ECC Studies (Method, Not College Station Invoices)

ECC does not publish a College Station or Texas dollar-per-square-foot average, and we do not have a College Station energy-code invoice to present as your number. We cite other studies as proof of method, and we label them that way.

On our 267-unit Cromwell, CT study (CS68), two buildings up to six stories (272,036 square feet) were filed on IECC commercial provisions using ASHRAE 90.1-2019 Appendix G. The recommended all-electric tier came in at about $35.23 per square foot net and captured a $1,500 per unit Energize CT incentive ($400,500). Those are Connecticut outcomes on an earlier ASHRAE year, not College Station invoices. They show the order: lock the path and edition, rank the packages, then document the winner.

On a 112-unit Revere, MA study (CS57), a seven-story mixed-use building kept dwelling units on a Massachusetts Stretch HERS path and still called for a COMcheck report for all common and support areas, plus ASHRAE 62.1 ventilation calculations and lighting power density calculations. The recommended ductless package landed at about $42.52 per square foot net. Those are Massachusetts outcomes. We cite them as proof that mixed-use paperwork splits before modeling hours, not as a College Station price.

Common Mistakes on College Station Multifamily Energy Filings

• Pricing a 2021 IECC package. College Station has been on the 2024 IECC since January 1, 2026. A package drawn for the 2021 codes that applied from June 1, 2022 needs to be rechecked.
• Copying a DFW 2024 package. Irving, Frisco, Plano, and McKinney are on the same edition but in climate zone 3A with different local amendments. College Station is climate zone 2A.
• Pairing the wrong ASHRAE year. The 2024 IECC commercial alternative is ASHRAE 90.1-2022, not 90.1-2019.
• Leaving the COMcheck out of the permit set. The City asks for 2024 IECC COMcheck compliance reports on multifamily permits.
• Assuming the testing exceptions remove all third-party work. The field verification exceptions still allow the code official to require an approved third party, independent from the installer, and the ERI path can require third-party verification too.
• Buying COMcheck or ERI hours before the path is locked. The study should settle residential vs commercial, 2024 IECC vs ASHRAE 90.1-2022 for commercial areas, testing vs field verification, and the R408 credits, then the paperwork follows.

When to Study First

Settle the College Station path before anyone buys REScheck, COMcheck, ERI, or whole-building modeling hours:

1. Confirm the permit address is inside the City of College Station (not Bryan or unincorporated Brazos County) and on the 2024 IECC as amended under Section 103-139 for your filing date
2. Lock the residential vs commercial split (three stories or less for Group R-2 / R-3 / R-4 on the residential provisions, and commercial documentation for nonresidential areas)
3. For each commercial portion, pick 2024 IECC commercial or ASHRAE 90.1-2022, and plan the COMcheck the City asks for
4. Ask the Building Official whether field verification or testing will be accepted for envelope and duct leakage on your building type, and whether a third party is required
5. Model envelope, window, ventilation, and HVAC packages side by side for climate zone 2A, including the R-6 duct with SEER 16 option and R408 credits, and compare the prescriptive, performance, and ERI paths
6. Produce the COMcheck reports, performance models, and test or verification records against the locked plan

That comparison is what a free feasibility study produces. For the Texas study method, see energy code feasibility study Texas. For how modeling works on apartment buildings in general, see multifamily energy modeling. If the path is already chosen and you need COMchecks, modeling, inspections, or testing, see ECC services.

Bottom Line

The College Station energy code for multifamily is the 2024 IECC with local amendments in Section 103-139 of the Code of Ordinances, adopted November 13, 2025 and in effect January 1, 2026. Those amendments add field verification exceptions for envelope and duct leakage, allow R-6 ducts with SEER 16 equipment, allow electric resistance heat in spaces of 500 square feet or less, delete interior lighting controls, and let the code official require third-party verification, all in climate zone 2A, and the City asks for a 2024 IECC COMcheck on multifamily permits. This is the College Station city-code door, not the statewide Texas code-path page, not the other Texas city doors, and not the Texas study door. Lock the split, the edition, and the testing plan first, then buy the paperwork that matches the plan.