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Editor's Notes

• #2: 10/13/05 draft Changes agreed upon at 10/11/05 meeting not yet incorporated into this draft: Early slide with compelling photos of elevated tasks and trenches and other dangerous conditions to get the audience’s attention. Better photo of tilt up wall panel and photo of prefabricated plumbing tree instead of steel stairs (Jack Donovan to send) on DfCS prefabrication example slide. Photo of permanent anchorage point on roof (John Mazourik) and cad drawing showing anchorage point locations (walter jones). This presentation introduces the design for construction safety concept and demonstrates why it is important as one piece of a holistic approach to enhancing construction site safety. The presentation was developed by the Design for Construction Safety workgroup within the OSHA Alliance Program Construction Roundtable. The Roundtable is a collection of non-profit professional organizations and individual companies who are participating in the Alliance Program.
• #3: Designing for construction safety (hereafter referred to as DfCS) represents a change from custom and practice whereby the design professional (that is, architects and/or engineers), and typically the project owner (that is, the client), become involved in facilitating construction site safety at the earliest stages of a project’s life cycle. DfCS is defined as the deliberate consideration of construction site safety in the design phase of a construction project. Many of you may be familiar with the term constructability, which usually refers to the idea of incorporating construction expertise into the design process to ensure the design is cost effective and buildable. Designing for construction safety can be viewed as ensuring the constructability review includes the safety aspects of the project. It is important to note that the designing for construction safety concept applies only to the design of the permanent facility, that is, to the aspects of the completed building that make a project inherently safer to build. The designing for construction safety initiative does not focus on how to make different methods of construction engineering safer. For example, it does not focus on how to use fall protection systems, but it does include consideration of design decisions that influence how often fall protection will be needed. Similarly, DfCS does not address how to erect safe scaffolding, but it does relate to design decisions that influence the location and type of scaffolding needed to accomplish the work. Design professionals (i.e. architects and design engineers) are in a position for decision-making and influencing to help improve construction safety in these and many other areas. For example, when the height of parapet walls is designed to be 42”, the parapet acts as a guardrail and enhances safety. When designed into the permanent structure of the building and sequenced early in construction, the parapet at this height acts to enhance safety during initial construction activities and also during subsequent maintenance and construction activities, such as roof repair. Without this consideration, constructors are solely responsible to design, prepare, and implement other temporary safety measures even if the design hinders the ease in which they are utilized.
• #4: Unfortunately, as many of us know, construction is one of the most dangerous industries to work in. In the U.S., construction typically accounts for just under 200,000 serious injuries and 1200 deaths each year. The fatality rate is disproportionally high for the size of the construction workforce. But statistics like these do not tell the whole story. Behind every serious injury, there is a real story of an individual who suffered serious pain and may never fully recover. Behind every fatality, there are spouses, children and parents who grieve every day for their loss. Because we all recognize that safety is an inherently dangerous business, all of us—including architects and engineers--must do what we can to reduce the risk of injuries on the projects we are involved in.
• #6: Mike recommends deleting this slide. The referenced article was written before I knew about the DfCS concept and was intended to show that designers cannot affect safety!
• #8: which results in fewer site conditions that lead to accidents (root causes)
• #9: The earlier safety is incorporated into the schedule the more influence it will have on the total project! One of the reasons that the DfCS concept is so compelling is that all safety professionals know that it is much more effective to design safety into a process than it is to try to manage safety within a process that is inherently unsafe. This chart has been adapted from the construction management literature. The ability to influence safety is on the vertical axis and the project schedule is on the horizontal axis. The chart shows that by including construction site safety as a consideration (along with production, quality, project scope, etc.) early in the project’s life cycle, one has a greater ability to positively influence construction site safety. This concept is in contrast to the prevailing methods of planning for construction site safety, which do not begin until a short time before the construction phase, when the ability to influence safety is limited.
• #10: The idea that decisions by design professionals do influence jobsite safety is not an unproven concept. Various researchers have show that design can influence construction site safety, both positively and negatively. For example, a 1996 paper by Professor John Smallwood showed that 50% of general contractors interviewed identified poor design features as affecting safety. A European study published in 1991 found that 60% of accidents studied could have been eliminated or reduced with more thought during design (European Foundation 1991). Researchers in the UK found that design changes would have reduced likelihood of 47% of 100 construction accidents studied (Gibb et al 2004). In the U.S., Professor Mike Behm found that design was linked to accidents in approximately 22% of 226 injury incidents in OR, WA and CA and to 42% of 224 fatality incidents between 1990 and 2003 (Behm 2004).
• #11: Need to acknowledge John Gambatese publication as source? This graphic depicts the typical DfCS process. The key component of this process is the incorporation of site safety knowledge into design decisions. Ideally, site safety would be considered throughout the design process. It is recognized, however, that a limited number of progress reviews for safety may be more practical. The required site safety knowledge can be provided by one or more possible sources of such safety constructability expertise, including trade contractors, an in-house employee, or an outside consultant. In the future, perhaps state and federal OSHA employees may provide such expertise. One question that sometimes is raised is whether the work product of a DfCS project looks different from that on standard projects. For now, the answer is “no.” That is, drawings and technical specifications on DfCS projects will likely at least initially look the same as typical documents, but they will reflect an inherently safer construction process. Eventually, it is hoped that construction documents resulting from a DfCS process will include safety enhancing details and notes that are not currently found on standard plans and specifications.
• #14: The University of Wisconsin at Whitewater has developed a construction safety curriculum.
• #15: Note to speaker: Insert specific examples related to your trade here. Need to replace steel stairs photo with plumbing tree or joist assembly. Need to replace concrete wall panels with better photo. Let’s take a look at a few specific examples of designing for construction safety. Reducing the hazards associated with working at heights is one area where DfCS can make a lot of difference. On the broad level, the use of prefabricated components such as prefabricated walls and the bridge segments and steel stairs shown here, reduces the number of activities that must be performed above the ground and therefore reduces the risk of fall-related injuries. Prefabrication can occur on site by site workers or off-site by specialty vendors.
• #16: Need to replace one photo of anchorage point with cad drawing showing anchorage point locations. Need to add photo of permanent anchorage point on roof. Identifying and/or designing needed anchorage points for fall protection systems such as body harnesses and lanyards is an example of how designers can use their understanding of structural engineering principles to make it easier for workers to use fall protections systems efficiently, both during construction and future maintenance. Specifically, designers can: Design floor perimeter beams and beams above floor openings to support lanyards Design lanyard connection points along the beams Note on the contract drawings which beams are designed to support lanyards, how many lanyards, and at what locations along the beams. The idea of identifying anchorage points on construction drawings is in accordance with Appendix C to Subpart M (Fall Protection) from the federal OSHA standards for Construction: (h) Tie-off considerations (1) “One of the most important aspects of personal fall protection systems is fully planning the system before it is put into use. Probably the most overlooked component is planning for suitable anchorage points. Such planning should ideally be done before the structure or building is constructed so that anchorage points can be incorporated during construction for use later for window cleaning or other building maintenance. If properly planned, these anchorage points may be used during construction, as well as afterwards.”
• #17: The previous examples did not affect the appearance or performance of the completed structure. Another set of potential DfCS decisions do result in a final design that is slightly different than what might have resulted had DfCS not occurred, but only those changes that do not unduly compromise the aesthetics or performance of the completed structure should be pursued. One example is including a parapet roof that is at 1.0 m (39 in.) high. Such roofs serve eliminate the need for additional guardrails during roofing and rooftop HVAC appliance installation and prevent the need for fall protection during future maintenance. Another example is designing upper story windows to be at least 1.0 m (39 in.) above the floor level. Having the window sill at this height allows it to function as a guardrail during construction. Skylights are another example. Specifically, designers can: Design permanent guardrails to be installed around skylights. Design domed, rather than flat, skylights with shatterproof glass or strengthening wires. Design the skylight to be installed on a raised curb.
• #19: Marvin will replace photo with site plan. Here is a DfCS example that involves sitework rather than an actual structure. This photo is associated with a site on which a construction worker was killed (electrocuted) when the drill rig he was operating got too close to the overhead power lines. The project environmental engineer specified that groundwater monitoring wells were to be dug directly under the power lines. If the construction safety were considered in the design phase, the engineer would have either a) specified that the wells be dug in another position away from the overhead power lines, and/or b) informed the construction company through the plans, specifications, and bid documents of the hazard and provided the necessary contact information such that the construction company could have contacted the power company prior to arriving on site. Clearly, the constructor had a responsibility for his employee and the design for construction safety concept in no way suggests that employers do not have primary responsibility for the safety of their employees. But this case illustrates that simply considering the safety of site workers during the design phase can result in easy decisions that have a major influence on a project’s inherent level of risk.
• #21: Americans generally consider themselves ahead of the rest of the world with regards to managing the safety of workers, but in designing for construction safety, the U.S. is lagging. Australia and several countries in Europe have had DfCS-related laws and/or initiatives for several years. The United Kingdom passed into law the Construction (Design and Management) Regulations (CDM), which became effective in 1995. Other European countries have since followed with similar regulations. The CDM regulations place requirements for addressing construction worker safety and health on design professionals. The crux of the CDM regulations affecting the design profession is that they place a duty on the designer to ensure that any design avoids unnecessary foreseeable risks to construction workers. Two specific examples from the CDM text are: Designers shall “ensure that any design…includes among the design considerations adequate regard to the need (i) to avoid foreseeable risks to the healthy and safety of any person at work carrying out construction work….” and “The design shall include “adequate information about any aspect of the project or structure or materials … which might affect the health and safety of any person at work carrying out construction work….”
• #22: It is recognized that many design professionals lack the necessary knowledge of construction safety and site operations to adequately design for construction safety. Fortunately, researchers, government offices and practitioners have developed tools that assist designers in designing for construction safety. Safety researchers sponsored by the Construction Industry Institute developed over 400 design suggestions that could be used by design professionals to minimize or eliminate safety hazards in their designs. These design practices were incorporated into a computer design tool titled “Design for Construction Safety Toolbox”, which can be purchased from the CII. The design suggestions are categorized according to project components, such as project layout, structural framing, and foundations. The Health and Safety Executive in the United Kingdom (the equivalent to the US’ OSHA) has developed several documents that help designers comply with the requirement that they design for construction safety. These documents are available on the website shown here. Safety professionals in Australia have created a tool called Construction Hazard Assessment Implication Review (CHAIR). CHAIR’s goal is to identify risks in a design as soon as possible in the life of a project and considers construction, operations, and maintenance activities. This process specifies that all stakeholders review the design in a prescribed and facilitated method to ensure that the occupational safety and health issues of these stakeholders are considered in the design phase of the project. Hecker et al (2004a, 212) described a Life Cycle Safety (LCS) process whereby construction worker safety is considered along with safety in operability, maintainability, and re-tooling in the conceptual and design phases of a newly constructed manufacturing facility. Trade contractors familiar with similar facilities were utilized to provide construction safety input during the conceptual and design phases of the project. While it is believed that these tools are practical and helpful, it is recognized that case studies are needed to verify the value of these tools and to identify ways to improve them.
• #23: Before ending the prepared portion of this session, I would like to summarize the presentation by reminding you that construction is too hazardous for any entity involved in a project to reject the possibility of contributing to a safer jobsite, including architects and engineers. The presentation showed there are strong ethical and practical reasons for design professionals to consider the safety of workers while performing their design, and there are several sets of tools to assist in designing for construction worker safety. The members of the OSHA Construction Alliance Roundtable Workgroup hope you will join us in promoting this important initiative.