Throughout this three-part series, we’ll explore the topic of flexibility in architecture. The first article examined the main reason for flexibility: change.

In this second article, we present three types of flexibility (adaptability, transformability, and convertibility) and how the healthcare field benefits from each.

The third and final article will study incorporating flexibility into the design process, along with specific architectural responses to various flexibility strategies. To view part one of the series, please visit: To read part three of the series, please visit:
Does flexibility in modern architecture apply to healthcare?
Historically, efforts toward flexible architecture have focused on building typologies outside of the healthcare sector, which tend to be less regulated and are less influenced by operational processes. Two modern theories by Peter Eisenman and Mies van der Rohe recognize infrastructure elements such as columns, vertical circulation, and floor penetrations as fixed and unchangeable components.

In van der Rohe’s open plan theory, certain elements contain the infrastructure that is fixed between start-state and end-state conditions. Other components, such as the skin and interior partitions, are less dense and easily removed or adjusted to compensate for a defined range of functions.

Eisenman’s theory focuses on section, not plan. His blurred zone concept prioritizes the control of the void: These are spaces that can be used for future expansion and growth. The blurred zone creates an interstitial space between levels and the opportunity to use the void for different conditions on each floor.

Healthcare facilities face more challenges in providing a flexible built environment than other types of architecture. Healthcare institutions no longer can afford for individual spaces to have one particular function throughout the lifespan of a facility; they must be flexible to respond to a variety of potential changes.

As a result, an increasing number of healthcare institutions are focusing on flexibility when designing their buildings to prevent early facility obsolescence. The ability to accommodate changing standards of care and space requirements reduces service disruptions, medical complications, and the need for capital expenditures to construct new facilities.

Although it is impossible to predict what future needs will be, there are several drivers of change (discussed in the first article of this series) that can be analyzed when designing for flexibility: increasing or decreasing volume, changes in service lines, changing patient mix and standards of care, increasing or decreasing size, and medical discoveries.

It is important to note that change is an indispensable element for flexibility. As Georgia Institute of Technology professor Craig Zimring, PhD, explains, “Flexibility is not an innate architectural quality, but the ability of the built environment to accommodate change between a defined start-state and end-state.”
Flexibility Types
Flexibility is defined within three types:

  • Adaptability
  • Transformability (including two subsets – moveable and responsive)
  • Convertibility

Each type of flexibility not only refers to the amount of change that occurs in the built environment, but addresses the degree of permanence of that change as well.


The capacity of the built environment to support multiple functions without altering the architecture is called adaptability. Different processes are accommodated through movable partitions, repositionable furniture, and other aspects of the environment that are able to change to accommodate the user or occupant.

The changes do not result in a permanent change to the space, and therefore the space can flex between the start-state and end-state with ease. The function changes, but the container does not.

Labor, Delivery, Recovery, and Postpartum (LDRP) rooms are an example of adaptability within healthcare architecture. The rooms can accommodate the different processes required for the more private and clinical stages of labor and delivery, as well as the more public processes of postpartum, including family visits.

The physical changes required to accommodate multiple uses are minimal, performed by the clinical staff, and are not permanent.


Through transformability, the interior or exterior space can be altered in response to external or internal stimuli without construction. Although this type seems to be the most common in general architecture, it is the least utilized in healthcare environments.

Transformability is both permanent and temporary. The ability to go back and forth between a defined start-state and end-state is permanent, but the states themselves are not. This type of flexibility does not require construction, although some user interaction might be involved. Within transformability, two subsets exist: moveable and responsive.

Movable structures are capable of being repositioned within the environment. The structure or object is not changed, but may be taken to entirely new surroundings. The resulting change is not permanent, but may require a greater effort or cost than other types of flexibility.

Also a subset of transformability, responsiveness addresses a facility’s ability to react to an outside condition, such as a weather emergency or viral outbreak.  The changes often are temporary and perhaps more labor-intensive than adaptable solutions, but allow for a greater scope of change.


This last flexibility type addresses a much broader scope than any other type and, as a result, is becoming increasingly used in the healthcare sector. Convertibility accommodates changing functions through a certain amount of construction. It reduces construction cost and time by anticipating the potential future needs.

Changes to the built environment that occur under convertibility responded to larger time and spatial scales. The resulting change is, more often than not, permanent.

Acuity-adaptable rooms use convertibility to facilitate change from regular inpatient rooms to intensive care rooms. The rooms are designed with the appropriate clearances for medical equipment and the ability to access additional medical gases and electricity, although not initially utilized.

When the facility identifies the need, the rooms can be converted with minimal construction effort, reduced time, and lower cost.


Designing for flexibility
Incorporating each type of flexibility into a building’s design should begin in the early planning phase of a project. These early decisions result in reduced cost as well as increased ease of implementation and potential for greater impact.

Additionally, as a project evolves it becomes increasingly difficult to incorporate these strategies.

The decision to incorporate flexibility strategies into a design can originate from a project’s
leadership, be it the owner, owner’s representative, a system’s CEO or board, or facility or project managers in charge of construction projects. They also may be suggested by the design team as a way to add value to the design.

Important resources during this process include initial feasibility studies, future projections, and area trends, as well as any long-term growth plans the institution might already have in place. Other valuable resources include the knowledge of frontline staff—nurses and doctors who can identify areas for improvement or environments where constant change is needed and difficult to achieve.

Regardless of how flexibility is brought forth as a design consideration, establishing specific flexibility goals is paramount to a project’s visioning process. Solidifying objectives into guiding principles assures that all team members are on the same page and understand what the team is trying to accomplish.

Once specific goals are determined, the design team can proceed in one of two ways. The first: research and explore a list of specific flexibility strategies to use. In this case, the team can review a pre-determined list of strategies and evaluate them based on compliance with the established flexibility goals, the site constraints, programming requirements and funding available.

The second: A design team can work with requirements for “known stages” established by the hospital. The determined start-state and end-state of the built environment will allow the design team to then creatively and innovatively produce specific strategies to achieve flexibility.

All three types of flexibility—adaptability, transformability, and convertibility—are applicable to healthcare facilities and are necessary for facilities to implement in design projects to lengthen the lifespan and future usability of the built environment.

Each type uniquely addresses the concerns rising from the unpredictability of the future that all modern healthcare institutes face. By preparing for potential end-states with specific design strategies, a facility can increase its flexibility in the future.

Robert J. Farrow, AIA, FHFI, LEED AP, is Principal and Senior Vice President at HKS Inc.; Amaya C. Labrador, Assoc. AIA, CDT, EDAC, is an Intern Architect at HKS Inc.; and Joshua D. Crews, Assoc. AIA, EDAC, is an Intern Architect at CDH Partners Inc. For more information, please visit