Landscaping Roof Terraces
Considerations for designing a rooftop terrace—safety, lighting, screens and more
When it comes to design—as long as your roof can bear the load of furniture, foot traffic, and plantings—the sky’s the limit.
Roof terraces are like stage sets, says landscape designer David Kelly, in that they're typically viewed from a single direction. "You can move around in a large garden," says Kelly, a principal at the Manhattan-based firm Rees Roberts + Partners, but these spaces are primarily experienced through a window." As a result, Kelly considers the view in tiers: what you see from inside constitutes the foreground, what's happening on the deck is the middle, and the view out to the horizon marks the distance. If set up well, Kelly says, "your eye has places to look at, rest, and then continue."
This New York terrace (left) provides the code-specified 42-inch-high safety handrail around its perimeter, but landscape designer David Kelly minimized its visual impact by using 3/4-inch-thick glass that cantilevers into the deck base, eliminating the need for visible vertical supports. To anchor a middle-ground view, Kelly designed a large ipe planter, filling it with a Serbian pine (Pinus leucodermis) and mondo grass.
Roof terraces are also meant to be used, he says, and the one featured on this spread not only includes room to relax but also to conduct agility training with the homeowner’s Portuguese water dogs. Kelly also likes to incorporate what he calls “the magic of the unexpected,” which on this project meant a miniature allée of nearly impossible-to-find pleached hornbeam trees that he underplanted with lavender.
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Narrowly pruned trees block unwanted views and demarcate the living space, which is appointed with a boxwood-filled antique French urn, planters from Pennoyer Newman, and aluminum versions of a 1954 Dan Johnson chair that flank a sculpture by Fernando Casasempere. Limestone floors extend from the home’s interior and abut a strip of paw-friendly SynLawn.
“I always use a simple palette of colors,” says garden designer Charlotte Rowe, whose plant picks for the terrace of a young London couple are dominated by greens and pale pinks. Rowe chose plants that could withstand wind and full sun, and most of her selections have a looser habit, allowing them to sway in the breeze and also to serve as a free-spirited contrast to the rectilinear bent of the built structures, whose streamlined aesthetic carries through from the railings and built-in seating to the embedded square light panels in the decking floor. Rowe has found several species that stand up well to terrace environments. For trees, she favors the olive (Olea europaea) and Juneberry (Amelanchier lamarckii). “Both can cope with the heat as well as the cold,” she says.
LEFT: The owners of this terrace, a young London couple who wanted an unconventional design, first had to reinforce their 100-year-old roof to bear the deck’s weight. Once secured, designer Charlotte Rowe installed a series of light fixtures that showcase the plantings, provide general ambience, and, as with the pink strip light, add a spark of the unexpected.
HARNESS COLOR AND LIGHT
Pictured here are anchor plants from the previous terrace, none of which require deep soil, a great plus in keeping weight load light. Clockwise from top left: Giant sea holly (Eryngium giganteum ‘Miss Willmott’s Ghost’), Mexican feather grass (Nassella tenuissima), Gaura lindheimeri ‘Whirling Butterflies,’ and fleabane (Erigeron ‘Dunkelste Aller’).
When two best friends and flatmates asked Data Nature Associates to revamp their Clerkenwell, London, roof terrace, they directed the firm’s principal, architect Nick Leith-Smith, to build them the ultimate party space. He designed cooking and lounging areas and two bars you can dance on, but to the side of an extra-large Jacuzzi he installed a special gem: an open-air shower (pictured) built of whitewashed oak posts with a Boffi shower head and a curtain of stainless-steel ball chains threaded into recessed aluminum channels.
Stainless-steel planters on either side hold a mix of tropical screening plants, including ginger lilies, cordyline, bamboo, and melianthus.
Conversations about landscapes often lead to the notion of borrowed views, but on a north London rooftop (pictured), designer Charlotte Rowe staked a permanent claim on the skyline with a sheet of bronze mirrored glass. Nepeta ‘Walker’s Low’ sits at the mirror base, and a supporting trellis plays host to star jasmine (Trachelospermum jasminoides).
The two sheets of mirrored glass both measure 35 by 91 inches. This sheet’s twin also acts as a water wall, bringing still more dynamism into the ever-changing reflected sky. Aside from their stand-alone beauty, the glass panels help establish different zones. “By breaking up the space,” says Rowe, “we gave it surprise and interest and made it feel larger.”
Fences and guardrails could be considered necessary evils, but they can push beyond mere function to achieve elevated form. Landscape architect Topher Delaney’s installation-cum-wall (pictured) is made of stainless steel that surrounds panes of both tempered and shimmering diachronic glass.
Delaney calls this residential rooftop “a study in blue,” not only for its panes of diachronic glass that constantly shift colors but also for the blue of the San Francisco Bay that fills most of the view.
London garden designer Stuart Craine chose a dwarf bamboo that won’t grow past the handrail so as not to obscure views of the street below.
For a Chicago rooftop, designers at Hoerr Schaudt Landscape Architects mounted screens of ipe and frosted plexiglass onto steel posts; the screens block a utility area and serve as a backdrop to Verbena bonariensis, alyssum, and boxwood.
For a hillside San Francisco roof deck that was on level with a public sidewalk, Rich Radford of the Garden Route Co. installed an ipe fence that provides a privacy screen; he chose lateral slats to go with the house built by real estate developer Joseph Eichler in the mid-20th century.
For the privacy fence of a bachelor pad terrace, stainless-steel posts support oak slats screwed into ipe spacers.