addressing construction worker safety in the design phase

Ž .Automation in Construction 8 1999 643–649www.elsevier.comrlocaterautcon

Addressing construction worker safety in the design phaseDesigning for construction worker safety

J. Gambatese ) ,1, J. HinzeUniÕersity of Washington, Seattle, WA, USA

Accepted 29 October 1998

Abstract

Facility designers can positively influence construction site safety by integrating safety considerations into the designprocess. Although their potential influence on safety has been documented, designers typically lack knowledge of and limittheir involvement in construction worker safety. This research effort involved the accumulation of suggestions for improvingconstruction worker safety while in the design phase. Using these design suggestions, a design tool has been developed toassist designers in identifying project-specific safety hazards and to provide best practices to eliminate the hazards. Althoughuse of the design tool is voluntary in the United States, it is one resource which can be used by designers to fulfill their

Ž .obligations required by the Construction Design and Management Regulations in UK. q 1999 Elsevier Science B.V. Allrights reserved.

Keywords: Construction worker; Design; Hazards; Injuries; Safety

1. Introduction

In the past decade, construction worker safety hasbecome a major concern of the United States con-struction industry. This is due in part to the highcosts associated with construction worker injuries,including the costs of workers’ compensation insur-ance, the indirect costs of injuries, the increasedchance of liability suits, and also the rise in criminalprosecutions of employers who allow work in unsafe

) Corresponding author1 Present address: Department of Civil and Environmental En-

gineering, University of Nevada, 4505 Maryland Pkwy, Las Ve-gas, NV, USA.

conditions. While many construction parties mightultimately bear a portion of these costs, the responsi-bility has primarily been placed on the employer,typically the general contractor.

Through the highly litigious nature of the U.S.construction industry, many parties have beenbrought into litigation regarding worker injuries. Thisis especially true of owners, a party to the construc-tion project which is often viewed as possessing themost resources. As a result, many owners have be-come more concerned about safety performance ontheir projects. Increased concern is evident in con-tract language which has tended to become moreproactive on safety. It is also evidenced through theincreased role that owners now play in monitoring

0926-5805r99r$ - see front matter q 1999 Elsevier Science B.V. All rights reserved.Ž .PII: S0926-5805 98 00109-5

( )J. Gambatese, J. HinzerAutomation in Construction 8 1999 643–649644

project safety during construction. In addition, own-ers commonly award contracts to firms who havedemonstrated the ability to deliver projects safely.

Despite the changes that have taken place in pastyears, there remains one party that has not beeninvolved in safety. This party is the designer. Safetyhas been a topic which, all too often, is overlookeduntil the start of the construction phase. This practiceignores the effect that designers have on constructionsafety. Perhaps no one has previously considered therole that designers play in influencing constructionsafety.

Designers play a very real role in influencingconstruction worker safety. It is the design thatdictates how a project will appear and how a particu-lar project or its components will be assembled. Themethods of assembly are often not recognized asbeing dictated by the designers. In reality, designersinfluence many decisions about how constructiontasks are undertaken. Unfortunately, designers havenot been cognizant of their influence and, as aprofession, they have not acknowledged the impor-tance or relevance of their role in safety. Somedesigners have stated that, in order to minimize theirliability exposure, they deliberately avoid addressingconstruction safety.

In the United States, designers are being encour-aged by some owners to specifically address con-struction worker safety in their designs. Designerinvolvement in the U.S. has largely been a voluntaryeffort. A clear shift from this is occurring in GreatBritain where recently enacted legislation, titled

Ž .Construction Design and Management Regulationsw x1 , has imposed an obligation on designers to ad-dress safety during the construction phase.

A common problem designers mention when theirinfluence on safety is intimated is that they lack theskills and training to address construction workersafety. While they might admit that their designsimpact safety performance, they contend that they donot know how to change their designs to improve orensure safety. This brings up the need for a centralbody of knowledge available for designers to addresssafety in their designs.

Some designers, especially those in design–buildfirms, already address construction worker safety intheir designs. These designers, of course, work withtheir fellow colleagues who are responsible for con-

struction of the project. By working together in thesame firm, they begin to appreciate each other’sconcerns. For example, the construction personnelmight alert the designer of how a particular connec-tion could hinder worker safety. Good ideas will beremembered and used on subsequent projects. It isunfortunate that this design knowledge is not accu-mulated and stored in a central location for alldesigners to access. The development of a centralbody of knowledge is an important first step inimproving the way that safety is addressed by de-signers. This body of knowledge must then be sharedby some means with the design community.

2. Literature search

Ideas on how to design for construction workersafety have not been well-publicized in the past.Literature discussing the subject is sparse. Researchand publications on construction worker safety hasmainly focused on the constructor’s role becauseOccupational Safety and Health AdministrationŽ .OSHA places the responsibility for safety on theemployer’s shoulders. The importance of the de-signer’s role in safety has only been briefly men-tioned. There is evidence of a need to educate and

w xinvolve the design community 2 , and to eliminatethe ‘hands off’ attitude designers often express to-

w xwards construction worker safety 3 .A recent study on the role of designers in con-

struction worker safety provides the most relevantinformation about design decisions concerning safetyw x4 . The study consisted of surveying design firmsand firms conducting constructability reviews regard-ing their involvement in safety. Conclusions from thestudy indicate that ‘‘for safety of construction work-ers to be addressed by designers on a regular basis oras an integral design function on all projects, adramatic change must occur in the mindset of thedesign profession.’’ The authors recommend that‘‘one of the means by which designers can becomemore responsive to the safety needs of constructionworkers is through education. Designers must bemade aware of the various means by which theirdesign decisions impact the jobsite safety conditionsfor construction workers. Such an educational pro-cess could begin with a compilation of the various

( )J. Gambatese, J. HinzerAutomation in Construction 8 1999 643–649 645

design approaches that have successfully addressedconstruction worker safety on past projects.’’

3. Research methodology

The main objective of this research was to searchfor and develop design suggestions or ‘best prac-tices’ which could be implemented in the designphase in order to improve safety during construction.The accumulated design suggestions would form thedatabase of knowledge for a design tool to facilitatetheir implementation.

To fulfill the objective of compiling design sug-gestions, the research effort focused on the construc-tion community itself. The goal of this effort was tocompile as many design suggestions as possible. Allsafety suggestions applicable to the design phase ofany type and size of project were recorded. Nodesign suggestions were discarded based on cost,schedule, relative risk reduction, or other design orconstruction performance criteria.

Although designing for construction worker safetyhas only recently been publicized, it was anticipatedthat some ideas have been developed and are cur-rently in use. Existing design suggestions were soughtfrom two resources: construction industry literatureand personnel. As part of the literature search de-scribed above, academic research and industry workpresented in various publications were reviewed forapplicable design suggestions. All design suggestionsfound were extracted and noted.

In addition to the literature search, constructionindustry personnel were contacted to solicit existingdesign suggestions. In-person and telephone inter-views were conducted to directly access their knowl-edge and gain from their past experiences. Majorpublic and private parties involved in constructionprojects, including owners, designers, constructors,design-builders, and construction managers, were in-terviewed. In order to reflect the entire breadth of theconstruction industry, firms of various design andconstruction disciplines were targeted. So that haz-ards of all types would be addressed, the interviewsfocused on firms of various sizes and on personnelinvolved in a diversity of projects. Personnel em-ployed at a variety of levels within a firm wereinterviewed to gain information which reflected vari-ous levels of work experience.

In addition to the search for existing best practicesto improve construction site safety, the research ef-fort included the development of additional designsuggestions. Three resources were accessed for de-veloping additional design suggestions: worker safetymanuals, safety design manuals and checklists, andthe research team’s personal knowledge and experi-ence.

It was felt that additional design suggestions couldbe developed from a review of typical constructionsite hazards and the safety measures prescribed toeliminate or reduce those hazards. The first sourceutilized to develop design suggestions was workersafety manuals, such as the OSHA, Army Corps ofEngineers, and other state construction safety manu-als. These manuals were created to provide guidancefor safety practices and conditions on constructionsites, and to direct and regulate construction sitesafety. In reviewing these manuals, an attempt wasmade to develop design suggestions which wouldeliminate the need to apply the safety measures orthe dangers experienced during implementation ofthe safety measures.

Another source of suggestions was safety designmanuals and checklists. Many large companies, aswell as state and national agencies, use safety designmanuals or checklists to address safety in terms ofthe ‘end-user’, such as the office worker, motorist, orplant operator. A review of these manuals and check-lists by the researchers focused on applying thetechniques used for enhancing end-user safety tosafety during construction.

4. Research results

To date, the research effort to collect designsuggestions has been very successful. Since the startof the research in early 1994, over 400 design sug-gestions have been accumulated. All of the designsuggestions are included in the final working versionof the design tool.

All of the targeted resources proved to be valu-able sources of design suggestions. Table 1 revealsthat the majority of suggestions came from safetydesign manuals and checklists. A good proportionalso came directly from the researchers and researchteam members and through interviews with industry


Table 1Design suggestion sources

Ž .Source Number of %suggestions

Safety design manuals and checklists 140 35.4Researchers and research team members 98 24.8

Ž .Interviews in-person, telephone 80 20.3Ž .OSHA CFR, publications, data 34 8.6

Journal articles and periodicals 29 7.4Other 14 3.5Total 395 100

personnel. Safety design manuals and checklists typi-cally address hazards during the startup, operation,and maintenance phases of a project. This resourcewas particularly fertile due to the close relationshipbetween the construction and startup phases, and theconstruction and maintenance phases. As a result, thedesign tool will also be useful for improving safetyin the startup and maintenance phases.

The relative success of the interview process canbe attributed to the construction industry’s interestand willingness to improve safety. This process re-vealed that personnel in construction and design–build firms were able to contribute a substantialamount of information. These types of firms aredirectly affected by construction worker accidentsand injuries, and their personnel know the inherenthazards in specific designs. Personnel in architecturaland consulting engineering firms were not as knowl-edgeable concerning design suggestions, possibly re-sulting from a lack of formal education about con-struction worker safety and their minimal involve-ment in overseeing jobsite safety.

On-site personnel and others who frequently visitjobsites provided the most design suggestions. Theseindividuals are involved in day-to-day constructionactivities and regularly address jobsite hazards. Simi-lar design suggestions were offered by personnelwho are involved in the design and construction ofsimilar types of facilities.

The great diversity of the construction industryled to the accumulation of design suggestions whichreflect all types of design disciplines, project compo-nents, and jobsite hazards. With respect to designdisciplines, as shown in Table 2, the most significantnumber of suggestions address the structural and

architectural features of work. Suggestions may re-late to more than one design discipline.

The accumulated design suggestions can also besorted according to what project component is af-fected. Table 3 reveals that piping was addressedmost often, followed by electricalrinstrumentationand mechanicalrHVAC components. Similar to thedesign disciplines described above, each suggestionmay apply to more than one project component.

Components typically designed by the structuralŽengineer foundation, structural framing, slab-on-

grade, floor, roof, stairs, ladders, ramps, walkways,.platforms were addressed a total of 145 times

Ž .36.7% . Similarly, components typically within theŽarchitect’s scope of work furnishings, finishes, pro-

ject layout, structure planrelevation, doors, win-.dows, handrails, guardrails , together with the work

schedulersequence, were addressed a total of 120Ž .times 30.4% . These percentages are echoed in the

significant number of suggestions which relate to thestructural and architectural disciplines shown in Table2.

All types of construction site hazards are ad-dressed by the design suggestions. The majority ofthe suggestions, as shown in Table 4, relate tohazards that may result in falls, followed by electri-cal shocks, cave-ins, and explosions. Many falls onconstruction sites occur due to the structural andarchitectural scope of work—the design of beams,columns, walls, stairways, ladders, etc. Thus, the

Table 2Design disciplines addressed by design suggestions

Design discipline Number of Percentage ofatimes addressed recorded suggestions

Structural 131 33.2Architectural 120 30.4Pipingrplumbing 76 19.2MechanicalrHVAC 68 17.2Electricalrinstrumentation 67 17.0Civilrtransportation 64 16.2Construction management 56 14.2Other 23 5.8Total 605

aSince design suggestions may address more than one designŽdiscipline, these numbers expressed as a percentage of the 395

.recorded suggestions exceed 100%.


Table 3Project components addressed by design suggestions

Project component Number of Percentage ofatimes addressed recorded suggestions

Piping 69 17.5Electricalrinstrumentation 56 14.2MechanicalrHVAC 54 13.7Structural framing 47 11.9Stairs, ladder, ramp 43 10.9Work schedulersequence 40 10.1Roads, paving, flatwork 32 8.1Slab-on-grade, floor, roof 30 7.6General conditionsr 26 6.6special provisionsEarthwork, sewer, etc. 24 6.1Furnishings, finishes 20 5.1Structure planrelevation 19 4.8Door, window 16 4.1Project layout 15 3.8Foundation 14 3.5Tank, vessel 14 3.5Technical specifications 13 3.3Walkway, platform 11 2.8Contract drawings 10 2.5Handrail, guardrail 10 2.5Total 563

aSince design suggestions may address more than one projectŽcomponent, these numbers expressed as a percentage of the 395


resulting large number of suggestions related to fallsis expected based on the large number of suggestionsrelated to structural and architectural disciplines andcomponents noted in Tables 2 and 3.

The construction site hazards addressed by thedesign suggestions are distributed in a manner simi-lar to OSHA’s fatality statistics. OSHA’s analysis of

w xconstruction fatalities from 1985 to 1989 5 revealedŽ .that the majority of fatalities 33% were due to falls

from elevation. This is comparable to the percentageof suggestions recorded that relate to fall hazardsŽ .33.7% . Similarly, the percentage of suggestionsrecorded that relate to electrical shock hazardsŽ .14.9% , is close to OSHA’s reported electrocutionsthat amounted to 17% of all fatalities. AlthoughOSHA statistics show that ‘struck by’ and ‘caughtinrbetween’ hazards are responsible for 22% and18% of the fatalities, respectively, similar high per-centages are not reflected in the distribution ofrecorded suggestions. This is probably due to theadditional categories that are reflected in Table 4,

many which might be regarded as subsets of struckby and caught inrbetween.

The following is a sample of the design for safetysuggestions recorded:

Ž .1 Suggestion: design components to facilitatepre-fabrication in the shop or on the ground so thatthey may be erected in place as complete assemblies.

Purpose: reduce worker exposure to falls fromelevation and being struck by falling objects.

Ž . Ž2 Suggestion: design parapets to be 42 in. 1.07.m tall.Purpose: while the Uniform Building Code stan-

Ž .dards require parapets to be just 30 in. tall 0.76 m ,modifying the design to increase the parapet height

Ž .to 42 in. 1.07 m would also satisfy OSHA guardrailrequirements. This modification eliminates the needto construct guardrails during construction, and alsoduring future roof maintenance operations.

Ž .3 Suggestion: design beam-to-column double-connections to have continual support for the beamsduring the connection process by adding a beam seat,extra bolt hole, or other redundant connection point.

Purpose: continual support for beams during erec-tion will eliminate falls due to unexpected vibrations,mis-alignment, and unexpected construction loads.

Table 4Construction site hazards addressed by design suggestions

Construction site hazard Number of Percentage ofatimes addressed recorded suggestions

Falls 133 33.7Electrical shock 59 14.9Cave-in 53 13.4Explosions 52 13.2Fire 41 10.4Toxic substances 33 8.4Work area 31 7.8Environmentrclimate 28 7.1Vehicular traffic 25 6.3On-line equipment 20 5.1Struck by objects 20 5.1Worker issues 18 4.6Obstructions 17 4.3Heavy equipment 12 3.0Confined spaces 10 2.5Caught inrbetween 6 1.5Lighting 5 1.3Total 563

aSince design suggestions may address more than one jobsiteŽhazard, these numbers expressed as a percentage of the 395



Ž .4 Suggestion: allow adequate clearance betweenthe structure and overhead power lines. Bury, dis-connect, or re-route existing power lines around theproject before construction begins.

Purpose: overhead power lines which are in ser-vice during construction are hazardous when operat-ing cranes and other tall equipment.

Ž .5 Suggestion: design and schedule a permanentstairway to be constructed at the beginning, or asclose as possible to the start, of construction.

Purpose: timely erection of permanent stairwayscan help eliminate fall and other hazards associatedwith temporary stairs and scaffolding.

Included in the research effort was the compila-tion of the recorded design suggestions into a designtool. The main objective of the design tool was toprovide a simple means by which a designer couldbe alerted of project-specific construction safety haz-ards, and be introduced to a variety of design sugges-tions which would eliminate or reduce the identifiedhazards. To fulfill this objective, a computer pro-gram, titled Design For Construction Safety Tool-Box, was created.

The program allows the user to access the sugges-tions by focusing on the project in one of three waysor paths: project components, construction site haz-ards, or project systems. Regardless of the pathtaken, the user has complete access to all of thedesign suggestions. All of the topics within eachcategory can be independently addressed. By select-

Ž .ing a topic component, hazard, or system , theprogram narrows its focus to only safety concernsand design suggestions regarding the topic chosen.After selecting a topic, the program presents ques-tions about the project. Answers to the questionsguide the program’s search for applicable safetyconcerns and design suggestions. The program thenpresents safety concerns and various design sugges-tions to mitigate those concerns.

5. Conclusions

Although interest in construction worker safety inthe United States has expanded to owners of con-struction projects, this interest has not spreadthroughout the design community. Except for thoseemployed in design–build firms, designers are typi-

cally not involved in the safety watch. Designerstypically distance themselves from the responsibilityfor construction worker safety mainly because oftheir lack of knowledge of safe designs and thepossibility of increasing their liability exposure. To-day’s design codes and regulations in the U.S. reflectthis attitude, and worker safety rests on the construc-tors’ shoulders. Currently, no national reference stan-dards exist to bridge the gap between existing designstandards and construction worker safety.

In Great Britain, the CDM Regulations have suc-cessfully addressed the need for designers to focuson worker safety, and outline mandatory steps foraction. The CDM Regulations direct the designer toparticipate in the identification and reduction ofhealth and safety risks. ‘‘The Regulations are notprescriptive; they avoid setting standards. Emphasisis placed on identifying hazards and the assessment

w xof risk 6 .’’ The CDM Regulations require designersto play a role in the identification of risks, withlimited guidance on how this assessment is to bemade. ‘‘Many designers currently lack skills in de-signing to avoid or reduce health and safety risk andthey feel uncomfortable and threatened by thew x w xR egulations 7 .’’ ‘‘The challenge facing designersis the ability to seek out and discover or developother techniques or construction methods to producethe same or similar results than a more inherently

w xhigh risk option 6 .’’ ‘‘It is suggested then that thedesigner develops a methodical approach to record-ing the design considerations with reasoned out-

w xcomes 6 .’’Complimenting the British effort, this research

takes that next step in addressing construction workersafety. In an effort to provide designers with therequired knowledge and tools, design suggestionshave been accumulated which provide designerspractical examples of how to design for constructionworker safety. A workable software package hasbeen developed which can effectively and efficientlyaddress project-specific hazards on all types andsizes of construction projects. The design tool will beuseful not only for improving safety in the construc-tion phase of a project, but also during the startup,maintenance, and de-commissioning phases.

While designer involvement in constructionworker safety in the U.S. is voluntary, the CDMRegulations are mandatory. The Design For Con-


struction Safety ToolBox is one resource which canbe used by designers to fulfill their obligations re-quired by the CDM Regulations in Great Britain. Itis interesting that this research seems to have thesame general objective as the CDM Regulations.There is little overlap in the actual work, and in fact,the efforts are highly complimentary.

6. Recommendations

Consideration of construction worker safety bydesigners can eliminate common safety hazards andreduce worker injuries. These benefits lead to areduction in project costs and liability potential. Al-though these points are widely understood and ac-cepted, a gap exists between constructors and design-ers in their knowledge of and commitment to jobsitesafety. As a result, information on designing forconstruction site safety must ultimately be drawnfrom the construction personnel and transferred tothe designers. Designers must be educated regardingdesigning for construction worker safety. It shouldbe recognized that construction workers are uniquefacility users and their safety warrants the attentionof designers.

Addressing safety in the construction phase notonly requires soliciting and publishing design sug-gestions, but also requires designers to change theirtraditional mindset. This requires a major educationeffort in the design community. In the United States,because of the possible increased liability exposure,designers may be reluctant to employ these safetydesigns. However, this reluctance will be diminished

when owners, those employing the designers, insistthat designers address construction safety concerns.Thus, owners must provide the initial impetus, byrequesting or requiring through contract terms, thatdesigners consider construction worker safety in theirdesigns.

Distribution and use of the design tool will helpfoster this change in the construction industry. Ex-tensive use of the tool will generate additional designsuggestions which can then be cycled back into thesoftware in future versions. Continued use of the toolwill also lead to further development of the program’sfunctionality to better fit the needs of the designcommunity.

References

w x Ž .1 The Construction Design and Management Regulations, SIŽ .3140 HMSO 1994 .

w x2 R.E. Raggs, J. Cunningham, Safety and efficiency in steelconstruction—the Broadgate experience, Civil EngineeringŽ . Ž .London May 1988 35.

w x3 S. Morpurgo, Accident prevention at dam construction sites,Ž . Ž .International Water Power and Dam Construction 44 8 1992

13.w x4 J. Hinze, F. Wiegand, Role of designers in construction worker

Ž . Ž .safety, J. Construction Eng. Manage. 118 4 1992 677–684.w x5 U.S. Department of Labor, Occupational Safety and Health

Administration, Analysis of Construction Fatalities—TheŽ .OSHA Data Base 1985–1989 1990 .

w x Ž .6 R. Joyce, The Construction Design and Management Regula-Ž .tions Explained, Thomas Telford Publications, London 1995 .

w x7 J. Jeffrey, I. Douglas, Safety performance of the UK construc-tion industry, Proceedings of the Fifth Annual Rinker Interna-tional Conference Focusing on Construction Safety and Loss

Ž .Control, Univ. Florida 1994 pp. 233–253.

addressing construction worker safety in the design phase

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