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

If you are building multifamily inside the City of Frisco, Texas, you are on the 2024 energy code, and the version you file against is the one Frisco adopted in June 2026. The City first moved to the 2024 International Energy Conservation Code by Ordinance 2026-01-05, adopted January 6, 2026, then repealed and replaced it with Ordinance 2026-06-42, adopted June 2, 2026. The City lists the 2024 IECC with amendments as effective June 2, 2026. The biggest commercial change in the June ordinance: Frisco deleted Section C405.15 Renewable Energy Systems in its entirety. That puts Frisco with Plano, McKinney, and Austin on the 2024 edition, while Dallas, Arlington, Houston, San Antonio, and El Paso sit on the 2021 IECC and Fort Worth and Corpus Christi on the 2015 IECC. Teams get caught when they price a 2021 IECC package, read the January 2026 text instead of the June 2026 text, or copy a McKinney filing that still carries the renewable requirement.

This page is the Frisco 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, and McKinney 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 Frisco Right Now

Per the City of Frisco Adopted Codes page and the City's adopted ordinances (primary sources; confirm with the City before you file):

• The City lists the 2024 International Energy Conservation Code (IECC), with amendments, effective June 2, 2026, under Ordinance 2026-06-42. The rest of Frisco's 2024 package (IBC, IRC, IMC, IPC, IFGC, IFC, IEBC, IPMC, and ISPSC) is listed as effective March 1, 2026.
• Ordinance 2026-06-42 amends Division 5 (Energy Conservation), Article IV, Chapter 18 of the Frisco Code of Ordinances. It adopts the 2024 IECC save and except the City's own deletions and additions in Exhibit A, and repeals Ordinance 2026-01-05 in its entirety. It took effect on passage and publication.
• The codified text is Section 18-223 of the Frisco Code of Ordinances, which now points to Exhibit A of Ordinance 2026-06-42.
• Ordinance 2026-01-05, adopted January 6, 2026, had replaced Ordinance 2022-11-57 of November 15, 2022, which put Frisco on the 2021 IECC.

Frisco sits in Collin and Denton counties, climate zone 3A (warm, humid), the same zone as Plano, McKinney, Dallas, Fort Worth, and Arlington. Same zone and the same edition as Plano and McKinney, but different local amendments. Do not copy a neighboring city's package.

What Frisco Changed in the 2024 IECC

The Frisco amendments in Exhibit A that matter most for apartment projects:

• C405.15 Renewable Energy Systems is deleted. The model 2024 IECC commercial provisions require renewable energy, on site or off site. Frisco removed the section entirely in the June 2026 ordinance; the January 2026 text did not delete it. Plano made the same deletion from July 1, 2026. McKinney kept the requirement with a one-year off-site agreement option. Three neighbors on the same edition, two different answers.
• Alternative compliance (C104.1.2 and R104.1.2). A building certified by a national, state, or local accredited energy efficiency program and determined by the Energy Systems Laboratory to comply may, at the Building Official's option, be considered in compliance. ENERGY STAR certification of energy code equivalency is considered in compliance. On the residential side, each 1- and 2-family dwelling is still tested for air and duct leakage regardless of path.
• Wall insulation enclosed on all sides (C402.2.8 and R402.2.14). Insulation in walls must be totally enclosed by framing, gypsum, sheathing, netting, or another approved material.
• Independent third-party testing on residential provisions. Mandatory air leakage and duct leakage testing may only be performed by certified individuals who are independent third parties with no employment or financial interest in the builder. Third-party inspection agencies must register annually with Development Services, hold RESNET, ICC, or BPI certification (others at the Building Official's discretion), and are subject to random review of site procedures, test results, and permit documentation.
• Required inspections (R107.2). A visual air sealing inspection alone cannot demonstrate compliance, all homes are tested for air tightness, and matching AHRI certificates, ACCA Manual J and Manual D, and an approved HVAC commissioning report are required on site.
• Ducts and ventilation (R403). Framing cavities may not be used as ducts or plenums (with a sealed interior return exception), ductwork is sealed with mastic, supply and return plenums are sheet metal, outdoor air intakes sit at least 60 inches from roofing below them, and exhaust-only ventilation needs an approved controlled source of filtered relief air.
• Residential envelope and ERI. An attic roofline option (U-0.035, or R-30 air-impermeable insulation below the roof deck when equipment and ducts are inside the envelope), field-sealed outlet boxes allowed in lieu of NEMA OS 4 boxes, R404.2 interior lighting controls deleted, and a replaced ERI table for climate zone 3 of 57 from September 1, 2025 to August 31, 2028, then 55 from September 1, 2028 (not including on-site power production).

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. With C405.15 deleted in Frisco, the study should not carry a renewable energy line item that the City no longer requires, and should not assume it away on a McKinney site.
• Garden-style and townhome projects. Three stories or less usually lands on the residential provisions, where Frisco's third-party testing, inspection documentation, duct, and ventilation amendments drive the testing plan and the HVAC submittal package.

Proof From ECC Studies (Method, Not Frisco Invoices)

ECC does not publish a Frisco or Texas dollar-per-square-foot average, and we do not have a Frisco 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 Frisco 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 Frisco price.

Common Mistakes on Frisco Multifamily Energy Filings

• Pricing a 2021 IECC package. Frisco is on the 2024 IECC. Dallas and Arlington are still on the 2021 IECC.
• Reading the January 2026 text. Ordinance 2026-06-42 repealed Ordinance 2026-01-05 in its entirety. The June text is the one that deletes C405.15.
• Copying a McKinney filing. McKinney is also on the 2024 IECC but kept the renewable requirement with a one-year off-site option. Frisco deleted it.
• Using the builder's own tester. Frisco requires mandatory air and duct leakage testing by certified, independent third parties, through agencies registered annually with Development Services.
• Leaving HVAC paperwork for the end. Matching AHRI certificates, Manual J and Manual D, and an HVAC commissioning report are part of the required inspections on the residential side.
• 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, the alternative compliance option, and the testing plan, then the paperwork follows.

When to Study First

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

1. Confirm the permit address is inside the City of Frisco and on the 2024 IECC as amended by Ordinance 2026-06-42 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 drop the C405.15 renewable line item that Frisco deleted
4. Decide whether an accredited program path, such as ENERGY STAR Multifamily New Construction, is worth using for alternative compliance
5. Model envelope, window, ventilation, and HVAC packages side by side for climate zone 3A, and line up a registered third-party testing agency early
6. Produce the COMcheck reports, performance models, and test results 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 Frisco energy code for multifamily is the 2024 IECC with the City's own Exhibit A amendments, adopted by Ordinance 2026-06-42 on June 2, 2026 and listed by the City as effective that day. Frisco deleted the C405.15 renewable energy requirement, kept alternative compliance through accredited programs and ENERGY STAR equivalency, and requires independent third-party testing on the residential provisions, all in climate zone 3A. This is the Frisco city-code door, not the statewide Texas code-path page, not the Houston, Austin, Dallas, San Antonio, Fort Worth, El Paso, Corpus Christi, Arlington, Plano, or McKinney 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.