In Brief
Design professionals can be held liable for construction safety even though they do not show authority, demonstrate control or are not contractually obligated to address safety.
Implementing prevention through design (PTD) on construction projects could help eliminate hazards associated with construction activities.
Implementing PTD not only reduces construction incidents, but also yields great benefits for project parties relative to schedule, morale, constructability, cost and quality.
Prevention through design (PTD), also known as design for construction safety, is the concept of protecting construction workers who build the designs by addressing their safety through the design process. Toole and Carpenter (2011) define PTD as "safety constructability." PTD is not related to managing safety of construction sites during construction, rather, its steps should only be conducted during the design phase of constructing a facility, whether by addressing safety in the design explicitly or by communicating hazards to contractors that cannot be reduced or eliminated.
PTD can have a significant influence on construction projects by reducing the number of injuries and fatalities. PTD is the most effective way to eliminate hazards associated with construction activities as shown in the hierarchy of controls (Figure 1, p. 54). The hierarchy of controls is defined by Tymvios (2013) as "a means to understand the importance of considering safety early in the lifecycle of a project." Figure 1 clarifies the five levels of control:
elimination;
substitution;
engineering control;
administrative control;
PPE.
Consider a typical example of a guardrail on a multistory construction building. Guardrails not only take a long time to install, but they also are not reliable. On a particular project, two fatalities occurred due to a broken guardrail on the seventh floor of the building during construction (CBC News, 2012). Conversely, guardrails can be installed using PTD concepts, for example, specifying holes in steel frames at 21 and 42 in. above the floor slab so that temporary guardrails can be attached using cables. In this case, a guardrail is not needed; the cables can act as a guardrail. The design delivers several economic and safety advantages. It is:
inexpensive;
easy to design (minimal design effort);
quick to install;
safe to build;
highly efficient.
