Are you a homeowner or building manager?
Find a Contractor »

ACCA Fights and Wins at Code Hearings

Posted on:

ANSI and ACCA Logos

ACCA was successful in getting nearly all of its code proposals approved during the first stage of the code development process. A summary of the Code Action Hearings (CAH) conducted by the International Code Council (ICC) last week is shown below. This includes some code proposals that we fought against (and won), including other observations.

Win – International Residential Code (IRC) – Mechanical

ACCA’s proposal to delete two exceptions under M1401.3, Equipment and appliance sizing, based on ACCA Manual S – 2023®, Residential Equipment Selection, was approved. The exceptions are no longer needed due to the new Manual S ® which is now specified by the 2024 edition of the IRC.

In addition, ACCA’s proposal to add Manual Zr®, Residential Zoning Systems, was approved. This was needed since the residential code does not have any guidance to address the design of zoned duct systems, such as what to do with bypass air when one or more dampers are closed.

Win – International Swimming Pool & Spa Code (ISPSC)

ACCA won a “double” approval, Manual SPS®, HVAC Design for Swimming Pools and Spas, which is recognized in two different places in the ISPSC. ACCA proposed adding Manual SPS ® to Section 326, Indoor Air Quality, and the Pool & Hot Tub Alliance (PHTA) proposed adding SPS to Section 325.5 for equipment room ventilation. It should be noted that the current 2024 edition of the International Mechanical Code (IMC) also specifies Manual SPS ® for dehumidification of indoor pools and spas.

Loss – ACCA IRC Proposal for Attic Stairs Rejected

For two consecutive code change cycles ACCA has proposed adding a requirement for a pull-down staircase or similar permanent attic access be required. The proposal was rejected again during the recent code action hearing for the 2024 IRC. Once again, the committee cited cost issues and clearance concerns that did not justify installing pull-down stairs if HVAC equipment is in attics for new construction. It should be noted that a majority of committee members represent building associations. ACCA’s proposal was based on a 2020 amendment to the Georgia building code, supported by one of ACCA’s Allied Contracting Organizations (ACO), the Conditioned Air Association of Georgia (CAAG).

Win – A New Hope?

The Virginia Plumbing & Mechanical Inspectors Association (VPMIA) testified in support of ACCA’s proposal during the hearing. Immediately following the code committee’s rejection, they approached ACCA staff and requested we work with them to propose a similar amendment for their state’s 2024 code adoption process.

Based on the above, ACCA will contact its ACO network to determine if there is interest in developing similar amendments to other state codes. It is hoped that such an effort will demonstrate to the ICC (and home builders) that this concern is not only a Georgia and Virginia issue but also applicable to other areas of the U.S. where HVAC and other equipment is installed in attics.

Wins – ACCA Fights Other Proposals

Return Air Paths: ACCA joined others in opposing several IRC proposals that tried to align existing mechanical requirements with the recent changes to the International Energy Conservation Code (IECC). The proposed 2024 IECC is not yet approved due to outstanding appeals. One such IRC proposal would have prohibited using framed existing building cavities for return air paths. Ducted returns are preferred, but this would be overly burdensome and costly based on widespread use of building cavities for return air systems. When used properly and sealed properly this methodology is acceptable. The committee rejected this proposal.

Cooling Systems: ACCA and others testified on a proposal adding a new section for “Cooling Systems” to the International Mechanical Code (IMC). The proposal would require interior spaces for human occupancy to maintain an indoor temperature at or below 80°F. The proposal was jointly submitted by several southern U.S. jurisdictions such as Phoenix and Tucson, AZ, and Miami, FL. The reason for this proposal was that the International Building Code (IBC) requires minimum heating of spaces for the safety of occupants (not less than 68°F), but is silent on requirements for cooling, despite the negative impacts on humans. It was noted that the IBC would be the appropriate place for this requirement, and not the IMC. ACCA pointed out that the proposal needed to specify a wet bulb requirement to go with the dry bulb criteria, and that it may be difficult to enforce in some areas of the country. After discussion, the IMC committee unanimously rejected the proposal. There may be a renewed effort to further revise the proposal and ACCA staff was approached to assist in this effort.

Hydrogen Blends: Another proposal of interest was to revise the International Fuel Gas Code (IFGC) to allow for “Hydrogen Admixtures” which blend higher amounts of hydrogen to fuel gas such as natural gas.  The proposal would designate higher blends of hydrogen with natural gas and have it treated the same as natural gas defined by the IFGC. This would potentially allow for natural gas to be blended with up to 20% hydrogen without any additional adjustments or modifications to the equipment. However, the proposal was rejected by the committee as the research report supporting this has not yet been released, plus a new test gas must be added to the ANSI Z21 family of gas appliance safety standards. The IFGC already has coverage for 100% hydrogen systems.

What’s the Next Step?

The ICC code change cycle has just begun its 3-year process. The decisions made at the code hearings will be posted online and open to comment from 16 May to 8 July. These comments can provide new insight to support code proposals that were rejected at the hearing and keep them “alive” for another round of committee action. The previous process had gone to a public comment phase with a hearing that did not include the applicable code committee, the public comment hearing went straight to ICC member online governmental ballot. The new process gives proponents and others another opportunity to engage the committee making the decisions, which will then be followed by a combined public comment hearing process. This new second committee action hearing will take place October 23 – 31, 2024, in Long Beach, CA, in conjunction with the ICC annual business meeting and expo. ACCA and its Codes Subcommittee will determine responses to some of the above reported actions and issues.

All of these efforts will result in the publication of the 2027 editions of the I-Codes.

For additional information and background please contact ACCA’s Manager of Codes & Standards at

David Bixby

Posted In: ANSI, Manual S

Looking for an ACCA QA Accredited Contractor?

Are you a homeowner or building manager?


join now

PLUS It's Risk Free!