Ladder Effect - the idea that if you put anything resembling a ladder in front of a person, they will climb it.
A 2007 report entitled Review of Fall Safety of Children Between the Ages of 18 Months and 4 Years in Relation to Guard and Climbing in the Built Environment” studied children’s ability and eagerness to climb. The report was commissioned by the National Association of Home Builders (NAHB) Research Center to clarify conflicting interpretations of guard climbing studies and injury data. The prohibition of ladder effect railings was originally included in the 2000 International Residential Code. Section R316.2 - “guardrails…shall not be constructed with horizontal members or other ornamental pattern that results in a ladder effect.” In 2001, that language was removed and currently, neither the International Building Code nor the International Residential Code refer to or restrict the use of horizontal members in a guardrail creating a ladder effect.
Over 40 peer-reviewed studies were consulted for the report covering the areas of children’s physical development and their interaction with the built environment. The report concluded that there isn’t a “completely safe” built environment and for the most part, children are going to be children – curious and adventurous. Climbing is involved in children’s physical, psychological, and social development. In fact, the more complex and difficult a barrier design may be to discourage climbing, the greater the challenge that is presented to the determined child.
The NAHB Research Center also analyzed Consumer Product Safety Commission (CPSC) data collected by the National Electronic Injury Surveillance System (NEISS). Following a thorough, scientific analysis, the review of the NEISS data reached the following conclusions:
- Falls from porches, balconies, open-sided floors, and floor openings protected by handrails, railings, or banisters, among young children aged 18 months to 4 years account for an estimated 0.032-percent of injuries in that population.
- The incident rate is approximately 2.5 per 100,00 children.
- There is inconclusive data to assign causality or the physical situation that led to the reported injuries.
The International Code Council recognized the above and in the 2015 International Building Code commentary, Section 1015.4 states
“The provisions of guards are to minimize accidental falls through or over a guard. Opening limitations do not prohibit the use of horizontal members or ornamentation infill as guard components. Research has shown that no practical design for guard infill, including solid panels, can prevent climbing; but good design practices can greatly reduce the opportunity for small children to “climb” the guard.”
Thus, while the IBC doesn’t prohibit horizontal members, they encourage responsible design solutions to discourage climbing. The Americans with Disabilities Act Accessibility Guidelines recommend installing additional handrails in instances where children are the primary users of the building or facility; with a handrail at 28-inches above the adjacent walking surface, in addition the three standard rails at 4-inches, 36-inches, and 42-inches.
Local codes, ordinances, regulations, and laws vary across jurisdictions. Some may adopt more restrictive provisions than the IBC, specifically addressing ladder effects in railings.
While proper adult supervision can be more effective than design restrictions to safeguard children, consider providing guards without horizontal members. Research, studies, and statistics suggest that it may make little difference, however, consider evaluating your design from the child’s perspective, especially where children are ever present and at play.
Disclaimer: The viewpoints expressed in this article are solely those of the author(s) and have not been approved by, reflective of or edited by other individuals, groups, or institutions. This article is an expression by the author(s) to generate discussion and interest in a particular topic. Though the article may cover specific legal and professional practice concepts, it should not be construed as professional advice. Always seek the advice of a professional licensed in your state for questions pertaining to the interpretation of laws and regulations.
About the author
Joshua Rubin, AIA, LEED AP is the technical director for Perkins&Will in their Washington, DC office and is responsible for creating a culture of technical excellence. Joshua sees himself as a teacher – tasked with creating an environment wherein the staff are empowered to ask questions, think critically, to be curious, and to fail successfully.
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