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Building Codes

NGA works with standards and codes bodies to promote and defend the use of glass in the built environment.

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In August 2021, the California Energy Commission approved a resolution adopting the 2022 Energy Code, commonly known as Title 24. The 2022 Energy Code will go into effect on January 1, 2023, following expected approval by the California Building Standards Commission. NGA’s advocacy team has been providing feedback on proposed changes to the teams developing the Title 24 update over the last two years. Overall, the new version of Title 24 will make significant advancement towards the state’s energy efficiency and climate change goals while also meeting their cost effectiveness requirements.

This includes new provisions that will push towards electrification and decarbonization, including a new prescriptive requirement for PV and battery storage systems on both new nonresidential and multifamily buildings. For the fenestration requirements in nonresidential buildings, there are no changes to the window area limits and only small updates to the curtain wall and fixed window U and SHGC. On the residential side, there are no changes to the window requirements in single family homes since they were just updated last cycle, but there will be a brand new separate standard covering multifamily buildings of all heights. To address the product differences in 1 story to 50+ story multifamily buildings, it lists separate fenestration requirements for curtain wall / storefront, AW class windows, and all other windows.

The pandemic has brought about a lot of changes to the way we occupy our existing building stock. Rehabilitating existing buildings to meet these new demands requires flexibility in the Existing Building Codes. Currently, California’s Existing Building Code has only one path for building rehabilitation: prescriptive path. The American Institute of Architects has called for California to adopt the three different compliance paths--prescriptive, work area and performance--that are now incorporated into the International Existing Building Code. Doing so would undoubtedly provide greater flexibility in the design and rehabilitation of California’s existing building stock. This effort is slated for California’s mid-term code cycle in early 2022.

NGA’s Energy Code Consultant, Dr. Tom Culp, Birch Point Consulting, Co-Vice Chair ASHRAE Std. 90.1, presented at the virtual DOE Building Energy Codes Program in the panel discussion “Looking to the Future - What's in Store for ASHRAE Standard 90.1.” Tom’s presentation focused on the onsite renewable energy requirements in 2022 ASHRAE 90.1. Other topics covered in this session are thermal bridging, envelope back-stop and HVAC metrics. Watch a recording of the session. See the full program and download presentation slides at

The International Code Council (ICC) is considering changes to the code development process based on issues presented to the Board Committee on the Long-Term Code Development Process (Blue Ribbon Committee). The board has approved two updates so far- cost impact and assembly consideration. NGA submitted public comments to the ICC Board in support of a proposal to use ANSI Consensus Procedures for future development of IECC. Read the comments

ICC 2021 Group A Online Governmental Consensus Vote (OGCV) opened October 15 and closed November 1, 2021. The final outcome of the proposals (what will end up in the next official Group A codes) is now final.

ICC Group B Hearings 

The International Code Committee (ICC) Committee Action Hearings for updates to Group B of the model building codes was held March 27 to April 6 in Rochester, New York.  

Group B  

  • Admin (Chapter 1 of all the I-codes except the IECC, IgCC and IRC) 
  • IBC Structural provisions in Chapters 15 – 25 and IEBC structural provisions 
  • IEBC non-structural provisions 
  • IgCC Chapter 1 
  • IRC Building provisions Chapters 1-10  

NGA Code Consultants Thom Zaremba and Nick Resetar of Roetzel & Andress and Tom Culp of Birchpoint Consulting will represent NGA and the Glazing Industry Code Committee (GICC) at the hearing, advocating on behalf of the glass industry. 

Remaining schedule

  • May 9: Results of the Committee Action Hearing will be posted on the ICC website
  • June 20: Deadline for online receipt of public comments
  • August 4: Public Comment Agenda will be posted on the ICC website
  • September 14-21: Public Comment Hearing, in person in Louisville, KY
  • Early October: Online Governmental Consensus Vote open for two weeks
  • Approximately November: Final Action posted following Validation Committee certification of Online Governmental Consensus Vote and ICC Board confirmation

Key to Abbreviations used in the Model Building Codes:

  • CAH Committee Action Hearing
  • GICC Glazing Industry Code Committee (within NGA)
  • IBC International Building Code
  • ICC International Code Committee
  • IEBC International Existing Building Code
  • IECC International Energy Conservation Code
  • IgCC International Green Construction Code
  • IRC International Residential Code
  • Group A & Group B the ICC divided the model building codes into 2 parts for the purposes of reviewing code provisions. 
  • PCH Public comment hearing
  • OGCV Online Governmental Consensus Vote

Learn more about the codes in NGA’s Guide to the Glass and Glazing Requirements of the Model Building Codes.

The 2024 IECC is now being developed with a consensus committee process similar to ASHRAE and ASTM to allow more technical consideration of proposals. This process is well under way with multiple committee meetings occurring every week considering different proposals. There are several proposals potentially affecting both residential and commercial fenestration criteria that will be heard in the coming months. NGA is well represented with our code consultant Tom Culp holding a voting position on the main commercial consensus committee as well as chairing the Envelope and Embodied Energy subcommittee. The committee actions will result in a second draft of the 2024 IECC for public review in late summer or early fall.  
Also, the ICC Code Correlation Committee recently met and confirmed that the final results of the residential 2021 IECC includes a “NR” or no requirement for SHGC for residential fenestration in zone 5 in the main U-factor criteria table. This corrects and removes an erratum that incorrectly stated that there was a 0.40 maximum SHGC in zone 5 in the U-factor table. The 0.40 SHGC was added to the R-value table by one proposal, but not in the main U-factor table, which remains as no requirement. This decision also removes a potential conflict for the Energy Star program, as a maximum SHGC of 0.40 in this northern zone can actually hurt energy efficiency, as confirmed by LBNL’s updated energy savings analysis.

2024 IECC Update

The International Energy Conservation Code (IECC) residential and commercial consensus committees are wrapping up their review of over 400 proposals in the first round of development of the 2024 IECC. In this new process, NGA’s consultant Tom Culp holds a voting position on the commercial consensus committee – the only one in the fenestration industry – and also chairs the commercial envelope subcommittee.

Over the winter and spring, there have been multiple calls each week of the various residential and commercial committees and subcommittees discussing, modifying, and voting on proposals affecting all aspects of the energy code. All approved proposals will result in a new revision of the IECC that will go out for a 2nd public review later this summer, and then the second round of public comment proposals will be considered by the committees and result in the final 2024 IECC.

So far, the residential committee strongly approved a GICC proposal to update residential fenestration requirements that was modified in a consensus proposal together with WDMA, FGIA, the New Buildings Institute, and 2050 Partners.

The commercial committee has approved new default U-factors for different spandrel assemblies, incentives for higher performance fenestration under expanded new “additional energy efficiency credits” requirements, tighter air leakage requirements, new requirements for on-site renewable energy including BIPV, and new thermal bridging requirements similar to ASHRAE 90.1.

The committee has rejected proposed envelope backstops that would restrict design flexibility, separate fenestration U-factors for midrise and high-rise residential occupancies, and a proposal that would have allowed NFRC ratings at actual project sizes to be used in the performance path. Dr. Culp will be reporting on the full details at NGA Glass Conference: Chicago and to the Glazing Industry Code Committee.

The consensus committees (including NGA’s consultant Tom Culp on the commercial consensus committee) are currently voting on the overall package of proposals. All items that achieve over 2/3 consensus approval will go out as the next draft for public review and comment this fall.  Any public comments and proposals will be reviewed by the committees over the winter and spring, and result in the final 2024 IECC.
Just this week, Aug. 16, the commercial committee approved their package of proposals on the second ballot; the residential committee will likely need a few more weeks to finalize their package of proposals.
One item of particular interest: our GICC proposal REPI-28 updating residential fenestration requirements that was negotiated together with the New Buildings Institute, WDMA, FGIA, and 2050 Partners was strongly approved and received no negative votes or comments. While it is possible for additional public comments to come in this fall, this gives high confidence that our proposed residential fenestration requirements are essentially complete and will be in the 2024 IECC.

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