Evidence-based design: A natural corollary to evidence-based medicine, evidence-based design (EBD) uses research and project experience to develop appropriate individual design solutions. In health care design, testimony is accumulating that natural materials, daylight and views of nature appear to affect healing outcomes in measurable ways.

"The whole field of evidence-based design is a new and emerging area," says Jocelyn Stroupe, IIDA, AAHID, Director of Healthcare Interiors and Principal, OWP/P Architects, Chicago, Illinois. "There's just so much more awareness right now from our health care clients and they like to do anything possible to help their patients heal faster and enable their staff to deal with the work-related stress."

Anjali Joseph, Director of Research at the Center for Health Design says, "In hospitals, many studies have shown that people do prefer natural environments over urban environments, and many studies have also shown that people prefer views with nature." She adds the center is working on ways to help architects who are conducting, or interpreting the type of primary research that is the hallmark of evidence-based design.

Leading architects are bringing nature indoors via hardwoods and other natural materials to the benefit of patients, their families and even staff. While occupant-centered and evidenced-based design are becoming accepted practice in health care, the knowledge is pertinent to any building used for living, working, playing or learning. Architects who ignore this growing body of knowledge may be missing a point of competitive advantage.

According to Katrina Barnett, AIA, of Radelet-McCarthy in Pittsburgh, Pennsylvania, her firm not only used hardwoods in the public spaces of several Pittsburgh hospitals, but also in patient care areas, "to make the patients feel more comfortable. The hardwood, a natural material, gives them an impression of something that is less institutional looking; it adds some warmth to the space."

Scott McFadden, Vice President and Director of Design at Maregatti Interiors, echoes that sentiment, saying that when his firm has used hardwoods, "We were trying to create an environment that felt very home-like and very friendly and we were trying to use materials that people would be comfortable with, products they maybe even have in their own home. Natural materials like wood and stone really do seem to help people feel more comfortable and heal as if they are in a more home-like environment."

In her health care designs, Ana Maregatti says she is "trying to evoke confidence, trust and comfort. We know that confidence goes with longevity and the materials we're selecting have to have longevity. That's why we're going to use natural materials like wood: it's been since the beginning of life. It's a material that gives you something you can count on."

Design Considerations
A hardwood product's durability, sustainability, life-cycle costing, environmental certification potential and aesthetics are all important design considerations.

Durability

Pro basketball is played on maple floors; freight trains run on oak rail ties; American hardwoods are durable under intense usage. However, some hardwoods are stronger than others and not all species are equally suited for all applications. The toughest commercially available American hardwood is hickory, and it is five times denser than aspen, one of the "softer" hardwoods which is not used for flooring. In descending order of durability on the Janka hardness scale, hickory, hard maple, red and white oak, birch, ash, walnut and cherry are the woods generally used for flooring and they all offer more than sufficient durability in active settings. The other American hardwood species work well in furniture, cabinetry, trim and architectural detailing.

In the 120,000-square-foot Lewis and Clark State Office Building for the Missouri Department of Natural Resources, Houston-based Berkebile, Nelson, Immenschuh and McDowell (BNIM) Architects specified locally harvested oak as a durable, sustainable flooring material for high-traffic areas such as the four-story atrium lobby and elevator areas. "We used solid white and red oak for flooring in the common areas," explains Kimberly Hickson, AIA, Principal and Manager of BNIM's Houston, Texas, office. "With any wood, if we are specifying it for flooring, we are looking at it for its durability."

In March, 2005, the Lewis and Clark building achieved LEED-Platinum status, one of only 14 other buildings in the U.S. that met the LEED-NC Platinum requirement of a minimum of 52 out of a possible 69 points.

American cherry was chosen for durability at the Hansen Center at Mary Margaret Community Center, Batesville, Indiana. "Primarily we used cherry because we needed it to function well, to hold up well, in a place that can be pretty abusive and we wanted to get the warmth of the richness of the color and the grain," says McFadden of Ana Maregatti Interiors. Cherry also was used for the bump rails that protect hospital walls from damage from equipment and medicine carts and patient guernies.