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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.

Review Current Activities

In August 2021, the California Energy Commission approved a resolution adopting the 2022 Energy Code, commonly known as Title 24. The 2022 Energy Code went into effect on January 1, 2023, following 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. 

NGA’s Energy Code Consultant, Dr. Tom Culp, Birch Point Consulting, Co-Vice Chair ASHRAE Std. 90.1, presented at the virtual Fall 2020 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 Group B Hearings 

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 represent NGA and the Glazing Industry Code Committee (GICC) at the ICC hearings, advocating on behalf of the glass industry. Read a summary of code changes relevant to glass and glazing. 

ICC 2024 – 2026 Building Code Development Cycle 

[May 2023] The International Code Council (ICC) will publish the 2024 I-Codes in late 2023 or early 2024. Looking ahead to the next edition, ICC published the schedule for the 2024-2026 Code Development Cycle. Upcoming dates of note are: 

  • June 1, 2023: Deadline to apply to join code development committees. 
  • October 16, 2023-January 8, 2024: Code change submittal period for Group A Codes. Group A includes the Fire Code, the Building Code’s fire safety and egress provisions and the Wildfire-Urban Interface Code. See the full schedule. 

The Code Hearings schedule is: 

  • 2024 Committee Action Hearings – Group A #1 - April 7–16, 2024 in Orlando, FL 
  • 2024 Annual Conference October 20–23, 2024, Expo October 20–21, 2024 and Committee Action Hearings –- Group A #2 October 23–31, 2024 in Long Beach, CA 
  • 2025 Committee Action Hearings – Group B #1 - April 27 – May 6, 2025 in Orlando, FL 

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. 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. 
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.

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. 

First round draft of 2024 IECC went out for public review in Fall 2022. 

IECC also moving very aggressively with strong steps towards electrification and net-zero.  Adding similar topics as ASHRAE 90.1:  

  • New on-site renewable energy requirement, even higher than 90.1, and option to use off-site renewables if can’t do on-site.  
  • New additional energy credits requirements. 
  • New thermal bridging requirements. 
  • Tighter air leakage and increased testing.

Have Codes Questions?

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