The Future of Evidence-Based Design

Sunlight has a number of positive effects. It provides people with Vitamin D, and has even been shown to ward off depression. But can it make us smarter or more productive? Evidence points to yes. Students who are fortunate to be in a classroom with large windows and skylights perform better on tests than those in rooms with very little natural light — between 7 percent and 18 percent better, according to research conducted more than a decade ago in the Daylighting in Schools study, administered by the Pacific Gas and Electric Co. Test scores go up even higher if the windows are operable. This is valuable information for an interior designer or architect hired to create an educational facility, and could potentially improve teaching and learning, as well as the productivity of the space and client satisfaction. Evidence can be a powerful tool used to inform designers’ and architects’ decisions.

Evidence is Based on Research

Traditionally associated with healthcare architecture, evidence-based design (EBD) is making inroads into being part of the process for designing schools, office spaces, hotels, restaurants, museums, prisons, and even residences. In short, EBD is when decisions about physical space are based on research and data.

“EBD took hold in hospital design because of the existing evidence-based medicine culture,” says David Watkins, FAIA, founding principal of Houston-based WHR Architects, and co-author of Evidence-Based Design for Multiple Building Types (2008).

Watkins suggests that EBD, less formally, already occurs in designing other building types. “We use facts to inform our designs,” he states, noting that rational experience, building codes and guidelines, as well as existing practices, such as post-occupancy evaluations, all provide designers with solid information that directs design decisions. His goal, through authorship and his practice, is to make it apparent that EBD cuts across all aspects of building design, and he pushes for a cultural shift in industry thinking, to include EBD as part of design services. In his book, Watkins defines EBD as “a process for the conscientious, explicit, and judicious use of current best evidence from research and practice in making critical decisions, together with an informed client, about the design of each individual project.” Watkins aims to broaden the healthcare-focused definition to include all building types and built environments.

It makes sense that EBD has its roots in healthcare, where lives are at stake and legal implications are palpable, outcomes are fragile, and decisions need to be justified by hard data. Watkins says, however, that this need for justification is becoming more commonplace in most other building designs. “Clients take risks when they make decisions, often having to defend their decisions to a board or their supervisors,” he says. It then trickles down, where the building professionals are held to a higher accountability for their design solutions.

After hospitals, schools are probably the second most obvious building type for using EBD, according to Watkins. In addition to the 1999 daylight study, there’s a growing collection of information linking colors with student behavior; classroom layouts with effective teaching; and finish materials with safety, all helping to improve the way education facilities are designed. A 2009 Herman Miller study showed that the adaptability of classrooms — such as seating, furniture, and operable windows — actually heightened the learning experience.

 “There is no single area of design that couldn’t benefit from this kind of knowledge and information,” says Amy Lopez, IIDA, AAHID, principal in Charge of Marketing and Business Development, WHR Architects, Houston. “Substantiated research can help all designers make better informed decisions.”

EBD in Green Design

Where EBD is making major strides is in green design, suggests Linda Nussbaumer, Ph.D., CID, ASID, IDEC, professor of Interior Design at South Dakota State University and author of Evidence-Based Design for Interior Designers (2009). “There’s a clear connection between sustainable design and the need to collect evidence,” she says. Thanks to the eco-friendly bandwagon, there is a rapidly growing body of performance data on mechanical systems, lighting, building orientation, water and energy usage, and indoor air quality. Often the results show links between these things and the well being of facility users. This trend will continue as manufacturers of green materials invest heavily in research, as more clients seek LEED certification, and as the USGBC requires measurable results.

In an effort to pair evidence with interior design, Nussbaumer has researched and written extensively about multiple chemical sensitivity, a medical condition sometimes exacerbated by exposure to products such as synthetic fabrics, paints, and petroleum-based building materials. As part of an interior designer’s responsibility to protect the health, safety, and welfare of building occupants, clearly any evidence linking a material with user discomfort — or worse, illness — should directly inform design choices.

Nussbaumer echoes Watkins’ hope that EBD eventually becomes a standard part of the design process. “We need to research what other designers have done and learned about similar situations before jumping into design ideas,” she says. As part of the pre-design process, she recommends “digging through articles and observing the project users.” But for it to be evidence-based design, beyond just gathering information and conjecture, is to do what the healthcare design field has done and follow a somewhat structured process.

Rob Tannen, director of User Research and Interaction Design at Bresslergroup, a product development firm in Philadelphia, advocates the use of EBD in interiors. He explains, “EBD has three main components: doing the research, testing, and seeing the results.” It’s similar to the scientific method, learned by most people in grade school, where experimentation and outcomes either support or disprove the hypothesis. Tannen adds that there’s no hard and fast rule for information gathering; EBD allows for multiple research methods. He recommends a balance of objective quantitative studies, with interviews and observation.

The Future of EBD
Rosalyn Cama, FASID, EDAC, interior designer and author of Evidence-Based Healthcare Design (2009), expects EBD to eventually become as common in the built environment as green design recently has, where it’s automatically part of the process. “In the future, I don’t know how you’re going to be an interior designer and not use EBD for accountability,” she says. In healthcare facility design, it’s not at all uncommon to see EBD included in RFPs as a project requirement. Just as sustainable design has added “LEED-AP” to the business cards of interior designers everywhere, right after IIDA and CID, The Center for Health Design recently created EDAC, short for Evidence-Based Design Accreditation and Certification. “It won’t be long before interior designers are doing research and looking for data on all types of facilities,” Cama says. She believes that clients will expect interior designers to know the evidence-based ins and outs of what they’re being hired to design.

As construction costs rise, codes increase and human-centered considerations flourish, clients will demand accountability and data-proven justification for most design decisions. Interior designers, in their effort to remain both competitive and innovative, will seek strategies that allow their expertise to shine. Technology will improve the ease and availability of existing research, and will improve digital user-feedback and data gathering systems. It’ll be a group effort. “Evidence-based design is going to have to be embraced by our whole profession and those who contract our services,” Cama says. Eventually all interior designers will open their windows, let in sunlight, and become more productive and smart, using evidence-based design.

David Whitemyer, AIA, is director of Production & project manager for Christopher Chadbourne and Associates in Boston, MA. This article is used (in part) with the permission of the International Interior Design Association, where it first appeared in their publication Perspective. The full text of the article can be found here.