With $99 billion in healthcare construction spending expected in the coming year, according to Dodge Data & Analytics’ “2021 Dodge Construction Outlook,” those pursuing new hospitals will likely face a decision on the type of floor plan to use on inpatient units. Some may seek solutions to place care teams closer to patients to enhance productivity and patient satisfaction, leading them to consider an open core model that distributes care team work areas along corridors within patient wings. This inpatient design can support caregiver performance and well-being by increasing daylight, visibility, and collaboration and reducing travel distances, while also improving the patient experience by making care teams more visible and accessible.

NBBJ designed its first open core hospital at the Great River Medical Center in Iowa in the early 2000s. The 144-bed replacement hospital in West Burlington developed an open core layout to create clusters of patient rooms with core support for intensive care unit (ICU), step down, and medical/surgical beds along a single corridor that enhanced staffing flexibility and minimized the need to transfer patients when census dropped. Since then, the approach has been refined through numerous projects around the country, including the next generation of open core design NBBJ has under construction. Here, insights and lessons learned from these projects are shared to underscore when an open core layout is appropriate for a healthcare system.

What is open core?
When it comes to designing the overall layout of a hospital, healthcare systems and designers have most commonly utilized a “racetrack” design with patient rooms wrapped around the exterior and offstage functions situated in a central block. This decision was largely due to historic regulations from the National Fire Protection Agency requiring windows in every inpatient room but not in staff support spaces. Open core is a fundamentally different solution. It meets the window requirement but challenges the racetrack paradigm by moving the major support functions (break rooms, staff lockers, conference rooms, offices, and all elevators) into a centralized hub that connects to multiple patient wings.

While most of the support areas are consolidated in the hub, some items most frequently accessed by staff, such as medication and medical supplies, are systematically deployed along the wings. The wings, specifically, are double loaded with patient rooms on both sides of a central corridor. The standard 8-foot-wide inpatient corridor is increased to 16 feet to accommodate circulation on one side and a clinical zone on the other; the clinical zone houses decentralized team workstations and supply/equipment alcoves. Each caregiver workstation typically has two seated positions and two walk-up positions that give direct visual sight lines to four patient rooms and maximize clinicians’ visibility of patients and of one another.

Advantages and trade-offs
The open core concept offers distinct advantages over traditional racetrack designs in terms of staff performance and well-being and the patient experience. For example, with nurses’ stations designed around enhanced sight lines, open core creates a high-performance environment that allows caregivers to see the entire wing at all times. This enhanced visibility supports rapid team response during emergencies and promotes team collaboration during normal operations by making work areas and caregivers more accessible to one another.

Staff well-being, a critical factor given the increasing prevalence of caregiver burnout and feelings of isolation, is an important focus of open core designs. Off-stage support zones, which are typically windowless spaces in racetrack designs, benefit from daylight and views by being on the building perimeter in the support hub. Open core layouts also reduce the distance traveled by nurses by putting patients and key supplies near their work areas. Most importantly, open core enables nurses to spend less time walking and more time providing direct care to patients.

Just as valuable, open core can enhance the patient experience. With care teams more visible and located closer to rooms, patients in open core hospitals have reported higher confidence in their care and reassurance that their caregivers are nearby.

Yet open core is not for every hospital. With these advantages come certain trade-offs, which hospitals need to consider. For example, although open core layouts are typically no larger than racetrack layouts, the shape of the open core floor plate is inherently more elongated than a racetrack design and usually requires about 15 percent more exterior surface area than a comparable racetrack layout. This increased exterior surface enables more daylighting opportunities for patient and staff areas, but it also requires a larger investment in exterior cladding.

Additionally, while open core projects can be accomplished with standard structural layouts, the structural system is often shifted to a non-orthogonal grid to further improve caregiver sight lines. On a new building project, the cost and return-on-investment calculation for this shift varies from project to project based on the building material (such as steel versus concrete) and the types of programs underneath the stack of inpatient floors, but it can result in a costlier structural system than racetrack. In cases where a non-orthogonal grid is utilized above and floors with orthogonal grids (such as operating rooms and emergency departments) are stacked below, a set of transfer beams has to be incorporated to resolve the differences between the two grid systems. Furthermore, open core is typically not suitable for renovation projects as it can be difficult to accommodate the grid.

Key considerations
Over the course of the past two decades, NBBJ’s approach to the design of open core hospitals has evolved by building on prior project experience and addressing the needs of specific clients. From this body of experience come several lessons and key considerations that can be critical to the success of the model.

Open core introduces not only layout changes but also significant operational changes that affect the care team as well as materials management, pharmacy, dietary, electronic medical records, and housekeeping. The success of the approach is tied to the effective alignment of every work stream. Using full-scale room mock-ups can help elicit detailed input from every department on design options for patient rooms and work areas and create hands-on ownership and buy-in around the design direction. This can be particularly useful for open core designs, where many elements may be unfamiliar to staff. For instance, staff frequently anticipate that open core will not enable ICU-level visualization of patients, but mock-ups can help illustrate the sight line performance.

With patient rooms located in proximity to work areas, open core also requires hospitals to review and resolve the issue of visual and acoustic privacy. Cubicle curtains can be used for visual privacy but do little for acoustic privacy and can be a hygienic concern unless sanitized consistently. Patient room doors work for acoustic privacy, but visibility needs require them to be transparent or glazed. A layered approach can be an effective solution, such as using disposable cubicle curtains and glazed doors, or doors with integral blinds or e-glass that can become opaque, to provide visual privacy.

Another key design consideration with open core is the location and contents of personal protective equipment cabinets and the amount of casework in patient rooms, which will vary greatly from institution to institution. NBBJ’s experience has shown that having adjacent supply alcoves outside each patient room can reduce overstocking and hoarding of supplies in and around the patient rooms.
Depending on the orientation and design of the facility, the increased daylighting that is a feature of open core may require additional design measures, too. For example, matte-finish flooring may be required to reduce potential glare from the additional daylight in patient wings. Using daylight modeling during the design process can help identify such considerations.

What’s next for open core?
The past 20 years of projects demonstrate the positive impact open core can have on staff, patients, and performance. Whether open core makes sense for a specific hospital project depends largely on its location, needs, and goals—but the layout has proven useful on a range of projects from community hospitals to academic medical centers to major Veterans Affairs facilities. As the healthcare landscape evolves and new projects are designed, we see open core continuing to adapt to address the challenges and opportunities caregivers encounter.

Ryan Hullinger AIA, NCARB, is partner and global healthcare practice leader at NBBJ (Columbus, Ohio). He can be reached at rhullinger@nbbj.com.