Bethesda Garden

An artistic use of light in a residential setting best describes this backyard and pool area in suburban Washington, D.C., but it almost didn’t come to pass. Although the clients had hired lighting designer Debra Gilmore for the interiors of their Bethesda, Md., home, they hadn’t realized that they could call on her expertise for the exterior landscape lighting as well. By the time Gilmore was back on the project, several months had elapsed since the interiors were complete, and a landscape plan was already in place. Construction of a stone retaining wall—as a good portion of the site around the patio and pool is a steep, sloped area—was well under way, so her task was to find the “moments” in the architectural landscape where it would make the most sense to add light. “It takes a big budget to spread light out over a large area,” Gilmore explains. “So our approach is to delineate by area.”

With the view from the client’s kitchen window and back steps in mind, Gilmore decided to first concentrate her lighting efforts on the water feature at the retaining wall on the far side of the backyard. The waterfall is composed of four flagstone slabs of differing lengths, ranging from 2-feet-long to 5-feet-long, that cantilever from the wall in a staggered formation. With input from a lighting manufacturer that she had collaborated with before, Gilmore developed a custom high-output white LED striplight with a damp-listing to graze the stone wall. Each linear LED array is housed in an extruded acrylic channel, which fits into a ¾-inch-wide-by-5/8-inch-tall edge detail on the underside of the flagstone slabs. Halogen accent fixtures with adjustable stems, located in the bed of river rocks below the waterfall, provide an endcap of light for this luminous feature. The overall effect is serene as the lighting captures the flow of water, the texture of the stone wall, and the flagstone slab edges to create a harmonious composition.

Rounding out this scene is a second layer of light, achieved with two theatrical projectors with dichroic filters, each of which is mounted on a 20-foot-tall pole at the corners of the house. They are cross-aimed to achieve a floodlighting effect on the hillside garden area above and beyond the retaining wall. A mock-up helped demonstrate this set-up for the client to alleviate their concerns about the height of the poles.

Next, Gilmore turned her attention to the house. Taking her cues from the waterfall, she illuminated the flagstone steps that lead from the kitchen and family room out to the patio with five, 4-foot-long linear arrays, this time with amber LEDs. “I wanted to be playful and mirror the asymmetry of what was happening in the wall,” she says. Small in scale but not without major impact, these vignettes of light transform the backyard’s hardscaped surfaces into something soft and fluid, and create a lighting vocabulary that complements this residential setting.

Project Bethesda Garden, Bethesda, Md.
Landscape Architect Ching-Fang Chen, Potomac, Md.
Lighting Designer Gilmore Lighting Design, Bethesda, Md.
Masons Williams & Williams Landscaping, Herndon, Va.
Photographer Jeffrey O’Connor, Washington, D.C.
Manufacturers B-K Lighting, Prolume, Tivoli