Keeping Up with the Codes

A History of Building Codes

Building codes have existed for quite some time. Depending on how you define them, you could assert building codes first entered the scene around 1750 BC with the Code of Hammurabi. Out of the 282 rules contained within that legal text, six relate to the construction of a home. We’ve come a long way from those ancient days in Mesopotamia; however, I might argue the spirit of the law has remained true over all this time.

The most commonly accepted building and construction codes across jurisdictions in the United States are the ones published by the International Code Council, or ICC. Before this one-source approach, the United States had regional-based codes:

  • Building Officials Code Administrators International (BOCA) on the East Coast and throughout the Midwest
  • Southern Building Code Congress International (SBCCI) in the Southeast
  • International Conference of Building Officials (ICBO) primarily throughout the West Coast and across a large strip of the middle of the country to most of the Midwest

The ICBO published the Uniform Building Code (UBC), Uniform Plumbing Code (UPC) and Uniform Mechanical Code (UMC). Some state codes—such as the Mechanical and Plumbing Code of The California Building Standards Code (“Title 24”)—are based on the UMC and UPC respectively. The UBC was replaced in 2000 by the new International Building Code (IBC) published by the ICC.


An Exception to the ICC: National Electrical Code

With minor exceptions across the country, most jurisdictions have adopted at least a small number of the building and construction codes written by ICC. However, if you’re an electrical engineer, contractor or enthusiast, you might be thinking about the National Electrical Code (NEC). This is one of the most interesting exceptions in the code world. The NEC is published by National Fire Protection Association (NFPA) rather than ICC. Their list of codes and standards total more than 300 and are numbered to easily identify them. In addition to the NEC (or NFPA 70), they also publish many codes and standards related to fire protection such as NFPA 72® National Fire Alarm and Signaling Code® and NFPA 13 Standard for the Installation of Sprinkler Systems. Although ICC used to have its own electrical code—the International Electrical Code—it has been replaced by the NEC as the standard for electrical codes.

You’ll rarely see a jurisdiction adopt by ordinance anything from NFPA other than the NEC. The reason for this is most of the codes and standards, such as those relating to fire alarms and fire sprinklers, are adopted by reference. Instead of adopting all the codes and standards that relate to a community, the ICC codes simplify the process and include language that will lump in these other codes and standards by referencing them. For example, section 101.4.1 of the IBC states that the International Mechanical Code (IMC) “shall apply to the installation, alterations, repairs and replacement of mechanical systems…” Instead of needing to adopt the IMC, it is essentially adopted by extension when the IBC is adopted since it is referenced in the IBC.

Over time, the content present in a code will become outdated. This is typically not due to an error or omission, but to the changes in construction technology and methods, a need to update technical definitions, feedback from the public and/or the results of research related to the current rules and regulations. Let’s look more closely into those four categories for an update to a code section.


Changes in Construction Technology and Methods

One of the most common residential permit applications our Building Code Services team has seen over the past few years is for photovoltaic (PV) solar energy systems. Did you know the rules for these systems were not in the residential code (IRC) until 2012? Keep in mind, PV systems for homes in the U.S. started gaining steam in the 1990s.

The construction industry is constantly looking to find ways to integrate technologies into homes, so it is important for the codes to stay on the forefront to allow for clear direction and expectations on how certain parts of a home are to be installed—while keeping everyone safe. Other examples of construction technology updates over the years include:

  • modular construction
  • structural insulated panels
  • engineered trusses and similar engineered wood products
  • spray foam insulation
  • strengthening concrete additives
  • integrated weatherproofing in exterior sheathing
  • fiber cement siding
  • high-efficiency windows
  • high-efficiency gas-fired appliances
  • heat pumps
  • plastic plumbing piping (such as PEX)
  • CSST gas piping
  • GFCI and AFCI circuit protection
  • concrete-encased electrodes (“ufer”)

One large update in this category for the 2021 IBC relates to energy storage systems (ESS) in dedicated use buildings. It is becoming more common to use facilities for the storage of modern battery ESS connected to the electrical grid. The implications for the flexibility of energy usage in our community are enormous; however, the increase in density of lithium-ion battery storage that is constantly charging and discharging was not explicitly covered in previous codes. The IBC determined this guidance needed to be added and decided on the occupancy classification for this type of installation: F-1 or Moderate Hazard.

The other large update is the expansion of the definition and regulation of Type IV construction, which had historically been referred to as “heavy timber.” As many new variations of heavy timber construction were entering the construction world, a more expansive list of regulations was required. No longer does heavy timber just relate to the rough-sawn wood beam construction we saw a century ago; this construction type has, for a few code cycles, lumped in buildings constructed with cross-laminated timbers (CLT). Type IV buildings now include Type IV-A, IV-B, IV-C, and IV-HT, with most of these differences relating to the protection of combustible structural members.

What will the future hold for construction technology such as 3D-printed homes? Without question, ICC will need (and is now actually discussing how) to address a common-sense standard for this and other future construction methods.


Technical Definition Updates

Although it appears tedious to drill down into the details of the definition of terms and clarifying code sections, this could be the most important update to the codes. Codes, by nature, are technical publications; each word, phrasing, or even punctuation could result in a completely different interpretation. One of my favorite examples of this is in Chapter 1 of the IBC, the chapter that relates solely to the administration of the code, where there are uses of the words “shall” and “may.” It is a minor difference on the surface, but a huge implication on a code section depending on which of these terms is present.

Updates to the 2021 IBC definitions (which all definitions are in Chapter 2) include the definitions for atriums, change of occupancy, impact protective system, mass timber, nailable substrate, penthouse, puzzle room and structural members. Other sections throughout the rest of the code have been modified to achieve more clarity, such as section 424 changing from “Children’s Play Structures” to just “Play Structures” (the idea is to include items like rock climbing walls that might not be just for children). Although the technical definition changes are too numerous to list here, each one was intentionally altered for a specific reason.


Feedback from the Public

ICC has a robust and long-established code development process. It involves people from the building community who fall into the categories of General Government (such as a building official or inspector), User (such as a building owner or private inspection agencies) or Producer (such as a general contractor or distributor). These individuals make up the committees that preside over the Committee Action Hearings. Members of ICC can submit changes to the code based on any number of reasons. Most often this is based on an experience in their local community. After a number of hearings and discussions, this is put to a vote by those eligible. Lastly, this is confirmed by the ICC Board to ensure it is in lockstep with the spirit of the codes.

One of the most discussed codes from the ICC is the International Energy Conservation Code (IECC). This code was born out of a need for the efficient management of energy it takes for a building’s systems to function properly. Over the years, there have been strong opinions, both for and against increasing regulations on a building’s energy efficiency. There is an obvious overall benefit to our community with increases in energy efficiency; however, the cost burden is typically shouldered by developers and contractors. For more news about the IECC, visit ICC’s dedicated webpage to the IECC.


Results of Research

Although ICC does not overtly state which studies or research cases have an impact on codes changes, said information has a cumulative impact on the members of the committee. Typically, these individuals are involved and up to date on the research being conducted in the construction industry which, in turn, affects their decisions on these code changes.

One example of this is the testing done for the determination of non-combustible protection for mass timber members. ICC worked with the American Wood Council (AWC) to confirm this approach matched the testing results (see AWC’s Technical Document 10). Simply stated, to provide a better protection of structural elements in a Type IV building, they need to be protected to a certain extent from fire. These sections (IBC 703.6 and 703.7) allow for flexibility in how to achieve that fire rating (through the attachment of gypsum panels or similar).



All told, there are fifteen building safety codes in the ICC family. Not all of them are adopted by all jurisdictions, nor is it required they are adopted altogether. Some of these codes only apply to specific regions of the country such as the International Wildland Urban Interface Code, which governs the design regulations to protect life and property from wildland fires and their effects. Another example is the International Private Sewage Disposal Code, which provides regulations for sewage disposal that is not a part of a utility system, most commonly a septic system. Here in the U.S., it is estimated around 26 million homes (one-fourth of all homes) are served by a septic system.

It is a colossal undertaking to implement the variety of necessary code changes; making it a wonder this can be done in a three-year period. It is entirely thanks to those involved in the committees and hearing processes for ICC (and NFPA) who devote their time—largely uncompensated—to help usher these changes through in a timely manner.

The Building Code Services team at GBA is committed to staying up to date on the most current changes to help ensure a safe environment for building occupants and to ensure a streamlined, efficient construction process with clear expectations on what the code requires.

Contact Us
Let’s Create Something Remarkable Together
We will bring the complete team to meet your needs and move your project forward. Contact GBA today.
Reach Out
Careers at GBA
It’s More Than Just A Job
GBA is a place where passionate, ambitious people come to learn & grow.
Explore Opportunities