The critical care unit consists of four major zones, each housing a primary function or set of interrelated functions.
  1. The Patient Care Zone consists of patient rooms and adjacent areas; its primary function is direct patient care.
  2. The Clinical Support Zone consists of functions closely related to direct patient care; not only inpatient rooms but also in other areas of the unit.
  3. The Unit Support Zone refers to areas of the unit where administrative, materials management, and staff support functions occur.
  4. The Family Support Zone refers to areas designed to support families and visitors.
Design for an optimally functioning unit will consider the requirements of daily workflows. Designers must also look to the long term. An effective ICU design must be flexible enough to accommodate changing care practices and advances in technology over the unit’s lifespan.
For prescriptive descriptions of the ICU, the most current edition of the FGI Guidelines provides square footage requirements for selected rooms. Several Society of Critical Care Medicine members have consistently participated in the development of the FGI Guidelines over the course of its numerous additions. The National Fire Protection Association code defines specific limitation on exiting and smoke compartment size.
The traditional design of critical care units has been influenced by reliance on a single paper medical record, central monitors, and regulations promoting a single, centrally located workstation from which all beds within the unit can be observed. These conditions are changing as information systems allow the digital record to be in multiple places at once, interdisciplinary care teams become more prevalent, nursing moves closer to the bedside, families become more involved in patient care, technology advances, and functions that had been centralized become decentralized.
Unit design begins with an in-depth analysis of patient care and support functions, workflow, and hospital policies (for example, those governing visitation and family involvement in care). An inventory of equipment and supplies, both current and future, will help to determine space requirements. The Clinical and Unit Support Zones are those spaces within the unit that directly support clinical and administrative staff. The design should reduce travel distances for staff, placing frequently needed spaces, equipment, or materials as close as possible to the site of use. The Family Support Zone should meet the needs of families and visitors while avoiding disruption to care processes.
The efficient unit is small enough for care providers to be fully aware of all activities on the unit or pod, yet large enough to permit efficient staffing. Whether a centralized or decentralized design is chosen, caregivers must be able to observe patients from many points within the unit. Research of the Society of Critical Care Medicine Design Competition-winning units suggests that there is no single ideal geometry for ICU layout. Published suggestions have proposed units or patient room groupings ranging from a minimum of six beds, for reasons of efficiency and economy, to a maximum of eight to 12 beds for reasons of observation. If there is a need for > 12 beds, consider arranging them in multiple pods.

Ref: Thompson DR, Hamilton DK, Cadenhead CD, Swoboda SM, Schwindel SM, Anderson DC, Schmitz EV, St Andre AC, Axon DC, Harrell JW, Harvey MA, Howard A, Kaufman DC, Petersen C: Guidelines for intensive care unit design. Crit Care Med 2012, 40: 1586-1600.