Human Factors in Building Code Expansion

“Have We Stagnated?” (STRUCTURE, December 2025), highlights a familiar trend: regulatory volume has grown dramatically. The engineering provisions of the 1967 Uniform Building Code filled roughly 280 pages, whereas today’s IBC ecosystem—including referenced standards such as ASCE 7, ACI 318, and the NDS—exceeds 2,000 pages. This raises a fundamental question: does an expanded code necessarily translate into better engineering and improved public safety?

Many engineers doubt it. Each new edition seems to introduce additional layers of provisions, exceptions, and cross‑references. Entire webinar programs now exist simply to help practitioners navigate increasingly complex changes to the building codes and standards.
A common justification for code changes is that modern buildings are more sophisticated, and therefore the codes governing them must expand accordingly. Fair enough. But structural drawings for buildings designed many decades ago often shows careful design and detailing and a knowledge of engineering fundamentals that rivals, or in some cases exceeds, what our profession does today using advanced analytical tools based on years of research (current powerful computer programs as opposed hand calculations using obsolete slide rules). So, this narrative is incomplete. Technical demands alone cannot explain the growth in regulatory volume—especially when most structures designed today are not fundamentally different from those of decades past.

A more convincing explanation lies in the human factors that shape how groups of individuals work and how building codes are written, maintained, and applied. Behavioral economics deals with how people respond to incentives, make tradeoffs, and rely on mental shortcuts. To illustrate this, we begin with a field far removed from structural engineering—business forecasting—and then draw parallels to building codes.

Time‑series forecasting models are widely used in business and can be evaluated against real‑world outcomes. In their study “Simple versus Complex Forecasting: The Evidence” (Journal of Business Research, 2015), Green and Armstrong compared 97 forecasting methods. Their conclusion was striking in that complex models rarely outperform simpler ones and often perform worse.

Yet complexity persists. These authors identified several human‑driven reasons:

The key insight is that complexity grows not because it improves outcomes, but because people are incentivized to behave in ways that favor it. Parallels exist in our building codes.

Structural engineers who serve on building code and standards committees know the dedication and public‑spiritedness of their colleagues, particularly those who have preceded them and may have personally encouraged them to get involved in support of the profession. These committees invest enormous amounts of volunteer time with the shared goal of improving the practice and better protecting public safety.

Yet individuals operate within a human‑systems environment that has a momentum of its own that sweeps those involved along like a strong river current. Swimming against the current is often a losing proposition. As a result, building codes evolve not only through perceived technical necessity or as a result of unprecedented storms and earthquakes, but also through the way people reason, make compromises, and respond to incentives in group settings.
Based on our own experience with committee work, the following human factors often drive building code expansion.

Risk Aversion and Fear of Omission. In engineering, the consequences of omission—real or perceived—are often far more feared than the costs of over‑specification. This asymmetry encourages the addition of provisions “just to be safe.” These layers accumulate over time. We are all guilty of this in one way or another, particularly in the writing of general notes and specifications for our design work. We all add language but rarely delete it. If we started from scratch, a lot could be deleted.

Patch‑Based Changes. Committees tend to favor incremental fixes over holistic revision. Imagine the reaction a newer member would get for suggesting a fresh alternative to the existing provisions—better to keep quiet! When a problematic issue arises, the natural response is to add language that serves as a patch closely following the status quo. Deletions and rewrites are less common, which is understandable given the limited resources of volunteer committees and the time such holistic revisions would take, not to mention the need to meet code cycles and deadlines. As the forecasting study showed, complex systems often grow through small, individually rational adjustments that collectively degrade overall effectiveness over time.
Legacy Provisions and Institutional Memory Loss. Once a provision enters the building code, it can become difficult to remove for several reasons. Committee membership changes, institutional memory fades, and the original basis for older provisions can be lost. Code credibility is maintained by following the status quo as much as possible. However, without periodic critical review, outdated requirements persist.

Battles Won and Lost. Building code changes are often driven by groups advocating for new provisions—requirements or allowances that favor particular new design checks, products, or systems. Once a proposal is introduced, positions harden, debate unfolds, and a final decision is eventually reached. The practitioner, who played a minor or negligible part in the process, then adapts to the new equilibrium. But the process doesn’t end there. Each new provision may create incentives for additional proposals in response, while the constituency that supported the original change remains firmly in place. Over time, these accumulated battles produce a predictable code expansion.

Incentives That Reward Complex Expansion. Complexity is often mistaken for rigor. Researchers gain prestige when their sophisticated work enters building codes and is cited in commentary. Practitioners can also benefit by becoming “experts” simply because they can navigate intricate provisions. Some firms can gain competitive advantage from complexity that raises barriers to entry and justifies higher fees. As in forecasting, complexity persists not because it improves outcomes, but because it aligns with the incentives of those who produce it.

Meaningful reform requires addressing the human environment in which building codes are produced. We offer three principles as a practical starting point for an improved path forward.

Make Deletion a First‑Class Activity

Most code cycles assume additions, whereas deletions are secondary, or non-existent. This mindset guarantees expansion as noted above. Committees can counter this by beginning each cycle with a review of provisions suitable for consolidation or removal. Establishing deletion targets can create the discipline needed to keep codes concise and focused on technical necessity and public safety.

Prioritize User’s Perspective

Technical correctness is necessary but not sufficient. Each proposed code change should be evaluated for its impact on user comprehension by addressing the following questions. Does it meaningfully improve public safety relative to the additional costs (engineering and/or construction cost)? Does it increase the engineering work by merely attempting to enhance so‑called code “accuracy”? Does it increase the number of steps required and the overall time required to apply the provision while also introducing the possibility of errors in implementation through unjustified complexity? Does it force the user to navigate multiple documents to answer a single question? Do structural engineers welcome the change as an improvement long needed? If the benefits do not clearly outweigh the added burden, the proposal should not advance.

Align Incentives with Usability

Our industry leaders can elevate usability as a measure of engineering excellence. Committees should be recognized for streamlining provisions and improving navigability. Incentives can be tied to quantifiable indicators such as reductions in word count and decreases in navigational complexity per McLean and Huston (2018) in “Navigational Complexity within Building Codes: Quantification and Affirmation,” (ASCE Journal of Professional Issues in Engineering Education and Practice). When usability becomes an explicit and rewarded outcome, committee behavior will shift in that direction.

Our profession has long accepted, reluctantly for many, building code expansion as an inevitable by-product of technical progress. However, human factors often contribute to code volume, such as risk aversion, incremental patching, legacy accumulation, and incentives that reward expansion over clarity.

Recognizing this phenomenon opens the door to meaningful reform. It asks our profession to value clarity as highly as safety, treat usability as a form of engineering rigor, and acknowledge that a code that few practitioners can fully navigate cannot achieve its purpose.
The opportunity for change is significant: to reverse decades of code expansion and build a regulatory framework that is both technically robust and genuinely usable.■