An estimated 75% of healthcare construction projects involve an expansion or renovation of an existing hospital. The healthcare construction industry is currently experiencing tremendous growth because of advancing technology, outdated healthcare facilities, an aging population, and increasing competition among healthcare providers. Because of this increasing demand—and the fact that an estimated two million infections are acquired in U.S. hospitals each year that kill approximately 90,000 patients, according to the Centers for Disease Control and Prevention—it is critical that care is taken to ensure that an infection-free environment is maintained during hospital construction projects. The construction manager plays a leading role in educating owners and the entire project team on mandatory guidelines to avoid the spread of infections during a project.

Infection Control Risk Assessment Defined

Over the years, many national agencies have released specific guidelines for hospital demolition, construction, and renovation projects that build infection prevention and safety into the planning process. However, the American Institute of Architects' 2006 Guidelines for Design and Construction of Hospital and Health Care Facilities dictate what is mandatory today and require that an infection control risk assessment (ICRA) be conducted prior to any healthcare construction project.

ICRA is a multifaceted, long-range plan that identifies and mitigates the risk of construction dust and debris causing contamination and infections in patients, hospital staff, and construction workers during a healthcare construction project. Each ICRA is project-specific and presents a diverse range of issues and challenges.

Designing a Project-Specific ICRA

The first step in conducting an ICRA is to get the entire project team—the owner, construction manager, engineer, and architect—to determine the risk level during each phase of construction. Key elements that affect the infection control construction plan include hospital traffic flow, disruption of healthcare services, project duration, and patient population in construction areas. It also needs to be determined whether solid wall or plastic protective barriers are necessary, how air-handling systems will be affected, and if the water systems will be affected
An important step to remember in dust and debris control is to wipe all wheels on the debris-moving cart before entering or exiting a construction zone. Photo courtesy of Skanska USA Building Inc.

Risk area classifications are based on the complexity of the project—number of workers and proximity to patients. There are four major risk groups in ICRA, one being the lowest risk area and four being the highest. These classifications dictate what level of precaution needs to be taken in each phase of the project:

  • Group One (Low-Risk Area). A classified low-risk area is a nonpatient care area. Examples of group one areas include offices within a hospital or medical records areas.

  • Group Two (Medium-Risk Area). A medium-risk group area has visiting outpatients and patient waiting rooms, and is not occupied by patients during weekends or off-hour shifts. Group two areas include radiology departments, as well as medical and surgical patient care areas.

  • Group Three (Medium-High Risk Area). High-risk areas include hospital cafeterias, emergency departments, intensive care units, nurseries, and laboratories.

  • Group Four (Highest-Risk Area). The fourth and highest-risk group includes areas of a hospital where the most sensitive patients are located. Examples include operating rooms, labor and delivery rooms, isolation intensive care units, and pharmacies.

Once all factors have been considered and each construction phase has been designated a risk group classification, the project team will then devise a plan for before, during, and after construction. The risk group a construction phase is classified under will determine which methods and materials will be used to maintain a safe and healthy environment
A plastic barrier with a permanent barrier behind it is a vital deterrent against spreading infection through dust and debris. Photo courtesy of Skanska USA Building Inc.

Methods of Infection Control

Dust and debris must be prevented from becoming airborne. For example, Aspergillus is typically associated with construction-induced air pollution at hospitals and can cause pneumonia and even death in immunocompromised patients.

One way to control dust and debris is to use physical wall barriers to isolate all construction and renovation projects from other hospital areas. Smaller projects generating minimal dust require fire-rated plastic sheeting, and the areas where these projects are conducted should be sealed at full ceiling height with at least two-foot overlapping flaps on doorways. For larger projects generating moderate to heavy construction dust, temporary barriers, similar to the ones mentioned above, must be constructed first. Once this happens, semipermanent barriers, which will last the extent of the project, can be constructed. Semipermanent walls consist of rigid, dust-proof, and fire-rated materials such as drywall and have caulked seams to ensure a tight seal. For extra-large and dusty projects, or for high-risk areas, an additional sectioned-off changing room is erected outside of these wall barriers. This room is for storing tools and changing clothing such as jumpsuits and shoe covers that workers need to wear in clean areas.

Dust and debris control is also achieved through the use of large adhesive “walk-off mats” placed at the openings of the barriers to collect dirt and debris from construction workers' shoes. These mats are like a giant notepad, in that sheets are ripped off and disposed of once they have been used.

A final precaution against dust and debris getting airborne is the use of carts with tightly fitted covers to remove construction debris via predesignated traffic routes. It is important to remember to wipe all wheels on the cart before entering or exiting a construction zone. Also, if chutes are used to direct debris outdoors, the chute opening must be sealed when it is not being used.

It is equally important to control airflow throughout the hospital to avoid airborne infection, paying particular attention to the heating, ventilation, air conditioning, and refrigeration systems. All construction areas must be negatively pressurized, which means fan units will continuously direct air, along with dust and dirt, back into the construction area. Air must be continuously flowing from clean areas to dirty areas. Alarm devices make sure that construction areas are negatively pressurized at all times.

Ideally, exhaust from construction areas is directed outside without recirculation. However, if air has to be exhausted into an interior space, fan units that negatively pressurize the construction zone must have their exhaust filtered by a high-efficiency particulate air (HEPA) filter. HEPA-filtered vacuum cleaners should also be used to clean up workspaces and to clean off construction workers' clothes before they leave construction areas.

It is important that construction workers understand their role and the importance of infection control measures before entering the construction site. For example, Skanska USA Building Inc., provides internal employee training sessions to educate its staff on infection control. Everyone needs to be aware of what to do in case of an unplanned loss of electric power, water, or air supply so that patients and the public will not be at risk.


Many professionals initially spend a lot of time planning and setting up infection control barriers and equipment when projects get off the ground. However, soon after the work begins, these same professionals do not maintain their environment. As projects progress, it is vital to continuously monitor the construction area according to the ICRA to ensure that a safe, infection-free environment is maintained at all times.

Most healthcare facilities have a full-time ICRA practitioner whose sole responsibility is to monitor the construction site and produce a daily report. Skanska also assigns a full-time employee to monitor, maintain, and report the status of all construction areas. If a deficiency is found, even if it is as minor as a temporary door gasket that needs to be replaced within the week, a responsible construction manager will not let the deficiency go to the next business day. Skanska's policy is for workers to stop what they are doing and remedy the deficiency immediately.


One of the reasons healthcare construction projects are more expensive than other types is because owners need to budget for an efficient infection control program. The construction manager, architect, engineer, and client need to preplan the infection control budget together. Project managers are constantly trying to reduce costs wherever possible, but qualified professionals know that you cannot skim when it comes to infection control. Enough money must be in the overall budget, as well as on-site, to maintain these conditions. Skanska advises clients to set aside approximately 1% of their overall budget solely for infection control. However, depending on how many different classifications and challenges a project presents, 1% may not suffice.


Working on a construction project in a hospital can be incredibly taxing, and a strict time schedule and budget pressures will most likely be part of the equation. However, with extensive planning and preparation, and proper training of workers and teamwork, a successful infection-free environment can be achieved. HD

Christopher I. Gilbert is a Senior Project Manager at the Philadelphia office of Skanska USA Building Inc.