Mobile/transportable medical units are used throughout the U.S. to provide easy, and sometimes free, access to medical and dental services, including screenings, diagnostic imaging, minor procedures, and non-emergency services. These units can be used to bring care to underserved areas or to temporarily house services during construction projects at a host medical facility.

While the medical services offered to patients in these units are often the same as those offered in permanent building structures, these mobile environments aren’t regulated by building and fire codes that require owners to maintain buildings and equipment within designated parameters. The Facility Guidelines Institute’s (FGI) Guidelines for Design and Construction of Hospitals and Outpatient Facilities is one such design standard adopted by authorities having jurisdiction (AHJ), but unless a mobile/transportable unit is part of a state-licensed medical facility, the guidelines generally aren’t applied. Previous editions of the guidelines outlined some design requirements for mobile units, but they didn’t provide the patient safeguards necessary for when interventional therapies are provided inside these units that they do when the same procedures are done inside a regulated medical facility.

To remedy this, members of FGI’s Health Guidelines Revision Committee (HGRC) decided to revise the chapter for mobile/transportable units during the 2018 revision cycle. The primary goal of these changes is to ensure patient safety for all medical services provided in this setting and to assign responsibility for assuring these requirements are met. The American Institute of Architects Academy of Architecture for Health (AIA-AAH) has three representatives on the 2018 HGRC who offered input on this topic throughout the comment period. All revisions to this chapter have been completed and will now be voted on for final approval by the HGRC. The following is an overview of some of the major revisions to the mobile/transportable medical unit chapter.


Creating consistency

Similar to other code committees, the HGRC is moving away from patient safety design standards based on the setting where medical services are provided and toward the idea of basing these standards on the types of services provided. The idea is that if minimal design requirements are necessary to complete a safe medical procedure inside a building, then why shouldn’t the same design standards apply to a mobile/transportable unit? The task group didn’t agree with older editions of the guidelines that mitigated requirements for mobile/transportable units due to the small size of the unit or its limited occupancy and instead wanted to find a way to scale reasonable requirements based on the services provided.

Fortunately, another guidelines task group had developed a classification of room types based on the procedures performed in the rooms and the acuity of the patient. The task group adapted this classification system to designate three different classes for mobile/transportable units based on increasing levels of medical intervention. Class 1 medical units are for services such as diagnostic radiography, fluoroscopy, mammography, CT scan, ultrasound, MRI, and other imaging modalities. Class 2 units can be used for diagnostic and therapeutic coronary, neurological, or peripheral angiography procedures and endoscopic procedures. Class 3 units provide locations for invasive procedures when the patient requires physiological monitoring and active life support.

Some variations to the design standards for Class 1 and Class 2 medical procedures, such as minimum clearances around the procedure table or between equipment, may be permitted if the owner completes a safety risk assessment regarding the acuity of the patients and the intensity of the medical procedures being provided and has the assessment and any alternative arrangements reviewed and approved by the AHJ.

Certain requirements were also outlined for each class, such as ventilation or electrical design. For example, Class 1 units that require positive or negative ventilated areas must meet ASHRAE 170, and all areas of Class 2 and Class 3 units must meet all of ASHRAE 170 ventilation and filtration requirements. Also, some required supporting spaces, such as clean and soiled utility rooms, storage rooms, and holding areas, are permitted to be provided in a host facility if the support areas are readily accessible to the mobile/transportable unit. If not, then they must be supplied within the unit, otherwise medical services cannot be provided from the unit.


New accountability standards

After clarifying mobile/transportable design standards for the three classes of medical units, the task group turned to the question of who should be held accountable to ensure these units meet all the conditions and requirements described in the guidelines. Since mobile/transportable units aren’t regulated for design, construction, or maintenance by any building or fire authority, the task group decided to offer several ways these units could be considered “certified” for initial installation. These include a process in which the professionals who designed the unit sign and seal the manufacturer’s construction documents, thus accepting legal responsibility for compliance (similar to the 2014 edition of the guidelines); using a third-party, nationally recognized testing laboratory certification or labeling of the unit (similar to a piece of medical equipment); or choosing other certifying means acceptable to the AHJ such as professional association certifications.

After initial installation, the host facility or the medical unit owner is responsible for keeping records of all maintenance items, as is required for any piece of medical equipment or patient care area. Each time the mobile/transportable unit is relocated to another facility for service and then returned to its original location, retesting of all systems must be completed and a written record maintained by the host facility, indicating continued compliance with applicable codes and standards.


Safer future

The guidelines provide minimum design standards for safety to patients receiving medical services, whether these services are provided inside a building or a mobile/transportable unit. Previous editions of the guidelines allowed a lower patient-safety standard in mobile units based on their size, but patient safety shouldn’t be compromised regardless of where or how medical services are provided.

By developing a tiered arrangement based on the degree of the interventional services provided, these revised standards aim to deliver reasonable design and maintenance requirements so the physical environment is safe, all while allowing this facility type to remain an important means of providing temporary healthcare services.

These recommendations will be voted on by the HGRC in April. Those approved will be added to the draft manuscript of the guidelines, which will receive another vote by the HGRC this summer, with publication of the final 2018 edition planned for late 2017.

The views expressed in this article are those of the authors and not the official position of the HGRC.

Skip Gregory, NCARB, is a healthcare code consultant based in Tallahassee, Fla., and chaired the mobile/transportable medical unit task group for the 2018 Health Guidelines Review Committee. He can be reached at Deborah Smith, AIA, is a registered architect and medical planner at Flad Architects (Tampa, Fla.) She is a member of the 2018 Health Guidelines Review Committee and can be reached at