Do all DFW cities use the same energy code?
No. The cities we checked name different editions of the International Energy Conservation Code (IECC). Dallas and Southlake list the 2021 edition. Highland Park and Frisco list the 2024 edition. Fort Worth lists the 2015 energy codes. This table reflects city pages read in November 2026.
A window that suits a house in Frisco may need a second look for Fort Worth, and the reverse can also be true. Always check the city where the house stands.
| City | What its page names | Where we read it |
|---|---|---|
| Dallas | Chapter 59: 2021 International Energy Conservation Code with Dallas Amendments | City code page, Building Inspection |
| Highland Park | 2024 IECC compliance signed by an energy consultant with ICC certification (plan checklist) | Residential builders packet |
| Southlake | 2021 International Energy Conservation Code, Ordinance 1247 | Residential guidelines, February 2026 |
| Frisco | 2024 IECC, with amendments, effective 06-02-2026 | Adopted Codes page |
| Fort Worth | The 2015 Energy Conservation Codes | Building & Energy Codes page |
| Texas (statewide) | Chapter 11 of the 2015 IRC for residential, effective Sept. 1, 2016; DOE lists the 2015 IECC | SECO and DOE pages |
We did not confirm a code edition for Plano, University Park, Westlake or other nearby cities, so they are not listed. The pages we found were blocked or unclear. Do not assume.
What does Texas require statewide?
Texas names the 2015 edition for residential construction. The State Energy Conservation Office (SECO), part of the Texas Comptroller, says it adopted Chapter 11 of the 2015 International Residential Code as the state’s residential energy standard, effective Sept. 1, 2016. The U.S. Department of Energy’s Texas page lists the current state code as the 2015 IECC.
SECO also describes how it reviews codes. Its adoption page says residential review runs on a six-year cycle, and that a new code takes effect not earlier than nine months after adoption. It adds that a municipality or county may adopt local amendments.
We did not confirm that Texas has adopted a newer statewide residential code since 2016. Check the SECO site for the current status.
Why do some cities list a newer edition?
Cities can adopt their own editions and amendments. Highland Park’s packet says the Town uses the 2024 IRC and 2024 I-Codes with local amendments. Frisco’s page shows its 2024 IECC took effect on 06-02-2026. Fort Worth’s page explains that the International Code Council publishes new codes on a three-year cycle and the city typically adopts new codes every other cycle.
Details vary, so treat each city page as its own source. If two pages in one city seem to conflict, call the building office.
What does an energy code mean for windows?
The energy code covers the building shell, which includes windows and doors. Two numbers do most of the work. U-factor measures how fast heat flows through the whole window. SHGC measures how much solar heat passes through the glass. Lower is better for both in a hot climate like DFW, but the exact limits depend on the code and the compliance path.
Fort Worth gives a clear example of the process. It says buildings that are heated or cooled must comply with the envelope provision “to ensure that energy isn’t wasted through the enclosing walls, windows and doors,” and that an envelope compliance report is required if you change the exterior walls, windows or doors.
Highland Park’s builders packet asks plans to show window and door sizes with SHGC and U-factor, with limits of SHGC under 0.25 and U-factor under 0.35. We explain that checklist in our post on Highland Park permits. We do not give window limits for the other cities here, because we did not read a published limit on their pages.
How do you read the numbers on a real window?
Use the NFRC label. The National Fenestration Rating Council label lists U-factor and SHGC for the specific product. See the glossary entry for the NFRC label and our guide to reading an NFRC label.
The label also shows visible transmittance and air leakage. Our entries on Low-E coating and the energy star climate zone explain two other terms you will see in a quote.
We do not print an ENERGY STAR number for DFW here. We did not open a current official ENERGY STAR page that shows it as text. Look up your zone on the ENERGY STAR site.
What should you ask before you order?
Ask your designer and the city. These five questions keep a permit on track:
- Which code edition does my city enforce today?
- Does my scope need an energy compliance report or a signed energy review?
- Do I need rated U-factor and SHGC for each unit on the plans?
- Who supplies the NFRC data, and in what format?
- If my plan changes, who resubmits?
Honey Rock works with Jada, Bertrand and Sun Windows. Makers publish ratings in different places and for different samples, so ask for the sheet for your exact configuration. Our pillar on energy-efficient windows in Texas covers the full picture.
Does the date of your permit matter?
It can. Frisco’s page, for example, shows its 2024 IECC with amendments took effect 06-02-2026. Codes have effective dates, so ask which edition applies to your permit date and your plan submittal. Ask in writing, and keep the answer with your drawings.
Next step
If you are choosing windows for a DFW build or remodel, send the address and the plans through /contact-us or call (214) 484-9982. For the wider story, read energy-efficient windows in Texas. This post is not legal advice. Your city’s building office decides what applies.
Questions people ask
What energy code does Dallas use?
The City of Dallas code page lists Chapter 59: 2021 International Energy Conservation Code with Dallas Amendments. The page says 2021 International Code Council codes took effect May 12, 2023. Check Dallas Building Inspection for amendments that affect windows.
Does Texas have one statewide energy code?
Yes, but cities can name their own editions. The Texas Comptroller's State Energy Conservation Office says it adopted Chapter 11 of the 2015 IRC for residential construction effective Sept. 1, 2016. The U.S. Department of Energy lists the current state code as the 2015 IECC.
Do window changes trigger energy code paperwork?
In Fort Worth, yes in some cases. The city says that if changes are made to the exterior walls, windows or doors, an envelope compliance report is required. Other cities handle it differently, so ask your city's building office.
Are energy code limits the same as ENERGY STAR numbers?
No. A code sets a legal minimum for a permit. ENERGY STAR is a voluntary label with its own criteria by climate zone. Read both, and check the NFRC label on the exact window you plan to buy.
Terms on this page
Sources
- City of Dallas: Current City Code
- Town of Highland Park: Residential Builders Packet
- City of Southlake: Residential Accessory and Addition Guidelines
- City of Frisco: Adopted Codes
- City of Fort Worth: Building & Energy Codes
- City of Fort Worth: Building & Energy Codes (envelope report)
- Texas Comptroller, SECO: Single-Family Construction
- U.S. Department of Energy: Building Energy Codes Program, Texas
Written by Honey Rock Window and Door and checked against the sources above on October 2, 2026. Product specifications and city rules change, so check the linked page before you act.
