Building Codes

ACCA helps contractors comply with building codes. And we help code officials understand HVAC.

The purpose of building codes are to guide government agencies in meeting their minimum obligations to protect the general welfare of the population they serve. Codes are designed to prevent damage to property, as well as injury or death to persons, and these objectives are accomplished by applying accumulated knowledge to the avoidance, reduction, or elimination of definable hazards.

Codes generally apply to the built environment and, when adopted by the pertinent authority, become lawful requirements that mandate compliance. An authority may write its own code document or may adopt other code documents. Different states and/or municipalities are free to adopt different codes.

Standards are usually regarded only as recommendations that do not have the force of law, unless the standard is adopted by the authority having jurisdiction. It is common for sections of a local code to refer to nationally recognized standards. In many instances, entire sections of the standards are adopted into the code by reference, and then become legally enforceable.

There are three main organizations in the United States who write codes that impact the indoor environment industry: IAPMOICC and NFPA.

Current Activities

There are no current code activities. Please check back frequently for updates.

Information for Contractors

Codes 101 Brochure

This brochure covers the basics of codes and standards and is aimed at providing contractors with a general understanding of these issues so that they can become more involved in the code development processes that affect the HVAC industry. Download it.

Residential System Design Review Form

ACCA has crafted an easy-to-use evaluation of HVAC system design elements in the pertinent building codes. Download it.

Computing Infiltration Loads based on a Target Envelope Leakage Requirement

This Technical Note shows how to convert a maximum code allowable leakage limit (say, 3 or 5 ACH 50 per the ICC International Energy Conservation Code) to a Manual J infiltration CFM value, and then to the infiltration load contributions (Btuh) for sensible heating, sensible cooling, and latent cooling. It also discusses the use of blower door data for one or more test points. Download it.

ACCA Codes Committee (committee members only)

Get involved in ACCA’s Codes Committee and make a difference in the development and adoption of good building codes. For more info about becoming involved in the Codes Committee and ACCA's building code efforts, contact

Information for Code Officials

Brochures for Code Officials

ACCA has developed several brochures which help code officials verify residential load calculations, duct design and equipment selection in accordance with Manuals J, D, and S. While it’s not practical for code officials to verify every single aspect of these submissions, these brochures offer checklists for a simplified verification process. Download them.

Load Calculation Software

An important warning notice for code officials about the dangers of inappropriate load calculation software. Download it.

ICC PMG Membership Council

Visit the International Code Council's (ICC) Plumbing Mechanical Gas (PMG) Membership Council webpage for other resources like CodeNotes, High School Technical Training Program Toolkit, and technical partners information.

Video Training for Code Officials

ACCA has developed a three-part video series that aims to help code officials better understand the three main aspects of a proper residential HVAC system design: a load calculation, selecting the appropriate equipment, and proper duct sizing.  The basis for the videos are the code-referenced ACCA Manual J, Manual S, and Manual D.  The videos do not comprise a design course, but instead provide an overview of the design process and presents ACCA-recommended verification points.  This will better enable code officials to verify that a system was designed correctly.


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ACCA in Building Codes

For years, ACCA's technical manuals and standards have been an integral part of the national model building codes' requirements for proper HVAC design.  The following model codes currently reference, or have in the past referenced, ACCA's various design manuals and standards:

  • IAPMO's Uniform Mechanical Code
  • IAPMO's Uniform Swimming Pool, Spa, and Hot Tub Code
  • ICC's International Residential Code
  • ICC's International Energy Conservation Code
  • ICC's International Mechanical Code

To see the detailed references in each model code, including section excerpts, please see the document for the specific cycle:

ACCA Codes Development Position Statement

The model building codes are intended to ensure that our buildings are safe, sustainable, affordable, and resilient; they contain the minimum safeguards for their construction. Though the distinct code-promulgating organizations have different procedures for the development of their various codes, they all include provisions for the call for, publication of, discussion about, and voting on public code change proposals. These code change proposals are (ideally) intended to refine the codes by addressing gaps or moving them forward in their stated mission. 

In practice, however, the various players in the code development arena (code officials, design professionals, code consultants, trade associations, builders/contractors, manufacturers/suppliers, and government agencies) may submit code change proposals that are intended to give a specific process, product, or organization special consideration in the administration of a code. 

As a national trade association that represents more than 60,000 professionals and 4,000 businesses in the indoor environment and energy services community, ACCA does not support changes to the model codes that would limit a designer's options to provide quality service to their customer. ACCA recognizes that any aspect of a building system may be installed incorrectly due to subpar field practices. However, these installation issues should be addressed through the development of consensus standards on the specific issue, and not by code banning a viable design alternative.


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