The Impact and Application of Evidence-Based Design

Posted by Douglas Elting on September 27, 2013


“We Shape our Buildings and Then They Kill Us.”

by Douglas V. Elting, AIA, ACHA, EDAC

Too often the way healthcare facilities are designed can cause significant harm. It is no secret that the way that architects and engineers design buildings has a significant impact on the lives of the occupants. These impacts can range from the simple and unnoticed to dramatic and life changing.

I have heard several definitions for Evidence-based Design (EBD). The official definition is “Evidence-based design is a process of basing decisions about the built environment on credible research to achieve the best possible outcomes.” (Oxford English Dictionary, 2000).

For us, the best definition is to “design a space so that doing the right thing feels natural.”

For thousands of years, healthcare professionals and designers have tried to do the right thing. Many of the design decisions were base on empirical evidence and good sense. Basic principles of large amounts of natural light, good ventilation and good hygiene were evident in Roman hospitals and in the work of Florence Nightingale. We have learned a lot since then. Sometimes, we have learned so much that we have lost sight of those three basic concepts.


What Should We Do to Make it Easier for Our Patients to Heal?

First, remove the known impediments to healing. Human beings heal faster if they have adequate rest, so design the hospital so it is quiet. Pathogens are spread through contact with contaminated persons and objects. Remove as many of these objects as possible, and make the rest easy to clean. Or, build them out of naturally antimicrobial materials.

The majority of patient falls occur on the way to or from the toilet. If you make the opening to the toilet four to five foot wide, caregivers or family can assist the patient. Reduce the number of steps by placing the toilet on the same side of the room as the bed. Give the patient control over their environment, and respect their privacy to reduce stress. Human beings are still similar to their ancestors; they are comforted by views of nature projected from comforting spaces.

Application of Evidence-based Design

Obviously, the proper application of Evidence-based Design is far more complicated than I have made it sound. There are thousands of interactions and processes in a healthcare environment that make it difficult to discern whether or not design changes have indeed resulted desirable outcomes. Many times, the best outcomes are a result of multiple factors working in conjunction with each other.

The positive impacts of EBD can be compromised by a clinical culture out of sync with its work environment. Since the turn of the last century, medical schools have largely ignored the built environment as having an impact on patient outcomes. Physical obstacles to proper safety procedures such as narrow toilet doors, poorly located electrical receptacles or medical gas outlets have been considered sacrosanct due to fear of capital expenditures. Hospital management, many times has focused on management programs, posters and monitoring systems in an attempt to overcome these hurdles. Hospital culture returns to old habits as soon as the pressure is off.

Often we castigate a nurse or technician for a pharmaceutical error resulting in harm to a patient and no one thinks to test for the number of foot candles of light above the compounding area. Instead, we live with a series of errors, damaged patients and tarnished careers for the wont of a two dollar light bulb. (Buchanan, T.L., K.N. Barker, et al. (1991). “Illumination and Errors in Dispensing.” American Journal of Hospital Pharmacy 48(10): 2137-45.)

Obviously, we have to do better. We need a different focus. We need to step away and observe what is happening from a broad perspective. Are we placing a privacy curtain between the patient and the sink and wondering why our hospital acquired infection rate does not change after we mandate hand washing?

How Do We Get Started?

Hospitals must be willing to share with the design and planning professionals their performance data. It may sound like airing out dirty linen, but the team is on your side, and we cannot help you if we are kept in the dark. The information must be mined, analyzed, and compared to known performance data from comparable institutions. Together, the hospital, and the design and planning professionals, must identify shortfalls and determine achievable goals and objectives. Together, we must define success.


The next steps are logical and sequential. Once consensus is reached and the goals and objectives are defined, the team must use their resources to create options and scenarios that utilize the best known scientific evidence to achieve, or exceed, the stated goals and objectives.

As early as possible, design solutions together with cost estimates must be compared to determine the return on investment (ROI). Keep in mind that evidence-base design does not consist of a “check list” of items for you to simply select those with the highest ROI or lowest cost and be successful.

Science and Art

Hospitals are highly complex, interactive institutions. Thus, it complicates the ability of researchers to isolate separate design features or acts that can be scientifically identified as positive or negative influences. Evidence-based design is both a science and an art. It consists of the science of implementing proven concepts and the art of understanding the intricate interactions that can occur between disparate concepts.

The tendency of design professionals is to place as many “good EBD features” as possible into each of their designs. It then becomes difficult to determine why a particular solution is successful or why it falls short of expectations.

“Technology, including the ability to combine building information modeling (BIM), integrated project delivery (IPD), and real time location systems (RTLS) with dynamic predictive analysis, will allow simulation of evidence-based design scenarios.“

This upfront investment has the capability to provide some comfort in decisions made affecting the design and operations and the facility will perform as predicted. The same system can be used after occupancy for proof of concept, and to provide a basis for further modifications or adjustments as healthcare services continue to evolve.

What We Have Learned about Evidence-based Design

• With evidence-based design, your patients will be more comfortable, exhibit less stress, heal faster and remain loyal supporters of your hospital.
• Your hospital will operate more efficiently and effectively and with a greater degree of safety for patients, their families and your staff.
• You will have reduced patient and staff injuries and hospital acquired infections. Together with lower operating expenditures, this will improve the hospitals financial performance.

To err is human. To have the evidence before you to do the right thing and choose not to is just dumb.

Douglas V. Elting, AIA, ACHA, EDAC
Managing Principal
Visions in Architecture