What is an Engineering Judgment (EJ)?

An engineering judgment (EJ) is a report issued by a credible organization that provides an assessment of component substitutions or installation deviations from a tested assembly. Engineering judgments, occasionally referred to as engineering analyses or engineering evaluations, are developed by engineers with expert knowledge and experience with the test method.


In lieu of conducting a new test of the proposed wall assembly, an expert will analyze the proposed assembly, the requested substitutions or installation deviations, any data associated with testing and judge its theoretical performance to determine if it also would meet the performance requirements of the test method.


Their analysis considers the individual characteristics of each component material, similarities of the proposed assembly to tested assemblies, and the risks associated with the change. Manufacturers or builders seeking approval of the change submit the engineering judgment and other supporting information either to the Authority Having Jurisdiction (AHJ) for approval or to their accredited third-party certification agency for use as evidence for consideration of changes to their Design Listings.


Engineering Judgments and Code Compliance

Engineering Judgments are permitted by the International Building Code, Section 104.11 and Section 703.2.2 when accepted by a building official. Section 104.11 states that an alternative material, design, or method of construction shall be approved where the building official finds that the proposed alternative meets all the following:

  1. The alternative material, design, or method of construction is suitable and complies with the intent of the provisions of this code,
  2. The material, method, or work offered is, for the purpose intended, not less than the equivalent of that prescribed in the code as it pertains to the following:
    • Quality
    • Strength
    • Effectiveness
    • Fire resistance
    • Durability
    • Safety

Section 703.2.2 allows the use of engineering judgments when based on a comparison of building elements, components, or assemblies designs having fire resistance ratings as determined by the test procedures set forth in ASTM E119 or UL 263.


ASTM E119 Large Scale Horizontal Fire Resistance Test
ASTM E119 Large Scale Horizontal Fire Resistance Test
ASTM E119 Large Scale Vertical Fire Resistance Test
ASTM E119 Large Scale Vertical Fire Resistance Test


Why use an Engineering Judgment?

Fire testing provides crucial information about the performance of an assembly, but it may not always be the best option when unforeseen circumstances arise. Engineering judgments are often used when:

  • A relatively minor deviation from a tested assembly is needed, such as substituting components in a tested assembly with a similarly performing component
  • Field conditions have made it impossible to install the assembly exactly as it was tested
  • Mistakes during the construction result in an assembly that does not match the tested assembly
  • No specific test can determine the as-built condition

Engineering judgments are developed by experts, including accredited third-party agencies, to prevent these circumstances from halting a project or creating an unsafe building. These are then submitted to AHJs or added new options to Design Listings of a Listing Report, such as an ICC-ES Evaluation Service Listing (ESL). Once approved, these options enable manufacturers far more flexibility to substitute products and components and offer alternate installation details to their customers and professional designers.


Manufacturers who value proactive solutions will often navigate the complexity of fire assembly testing by working with an accredited third-party agency before running the tests. An experienced agency will discuss the client’s needs and goals to build a test plan which details the assemblies that should be tested and the assemblies that should be approved through engineering judgments. The test plan minimizes the amount of large-scale testing, which typically results in a much faster and less expensive path to code compliance.

About ICC NTA, LLC: As an accredited third-party agency and part of the International Code Council(ICC) Family of Solutions,ICC NTAprovides code evaluation, inspection, engineering, plan review, and product testing services, as well as independent quality and standards compliance verification for building product manufacturers. With offices, testing labs, and training facilities in Nappanee, Indiana and Bryan, Texas, ICC NTA serves residential and commercial builders, code officials, manufacturers, and suppliers throughout the building industry.


Lieburn, Brian and Lorraine Ross. “Engineering Judgments: The Good, The Bad, The Useful.” 2019 Annual Conference Educational Sessions. October 2019. Las Vegas, Nevada. https://www.iccsafe.org/wp-content/uploads/Engineering-Judgements-The-Good-The-Bad-The-Useful.pdf. Accessed 06/30/2022.

“SAF NFPA 285 Course.” YouTube, uploaded by Southern Aluminum Finishing Co, Inc., 12 May 2022, https://www.youtube.com/watch?v=bjgt5E4xOIs&ab_channel=SouthernAluminumFinishingCo%2CInc. Accessed 06/24/2022.

NFPA 285 Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Wall Assemblies Containing Combustible Components. National Fire Prevention Association, 2019.