Landscape architects mix art, engineering, geology to create enjoyable spaces

(Roger K. Lewis)
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By Roger K. Lewis
Saturday, September 11, 2010

The aesthetic character of a city depends on the design of open space -- streets and parks, squares and plazas, courtyards and gardens -- as much as the design of individual buildings. Often exterior spaces are no less memorable than grand civic edifices, venerable churches and elegant homes.

Washingtonians, as well as visitors, appreciate not only the capital's familiar architectural icons, but also its Mall, parklands, avenues, circles and squares. Lafayette, Farragut and McPherson squares, the U.S. Navy Memorial and Lincoln Park are a few of the urban spaces that give Washington its unique identity. In Alexandria and Annapolis, streetscapes and waterfront promenades likewise impart some of the most lasting impressions of those historic cities.

City planners generate master plans delineating street patterns and the general shape of civic spaces constituting the public realm. Architects design buildings occupying such spaces. But it is often landscape architects who design in detail the open spaces set forth in master plans, who transform conceptual spaces into real spaces that ideally are beautiful, functional, safe and environmentally sustainable.

Like building architects, professional landscape architects must manage several disciplines. Their knowledge base and design skills overlap those of town planners and architects, civil and structural engineers, geologists, botanists and even historians. Landscape architects are much more than just glorified gardeners.

Like building architects, landscape architects strive to achieve the essential elements of good design -- "commodity, firmness and delight" -- enunciated by the Roman architect Vitruvius nearly 2,000 years ago. And, of course, landscape architects are expected to stay within budget.

Landscape architecture projects vary in scale and type, ranging from intimate gardens and courtyards to urban plazas and parks, from a block-long street to a miles-long highway. Landscape architects design rooftop gardens, office building and shopping center atriums, business and industrial park sites, airport grounds and educational campuses.

Landscape projects typically are simpler than building projects. Buildings encompass engineered foundations and structural skeletons; thermally resistant, waterproof skins, and energy-efficient HVAC, electrical, lighting and plumbing systems. Building design and construction is strictly regulated in accordance with voluminous safety codes.

Nevertheless landscape architects have their share of functional issues to deal with: pedestrian and vehicular circulation, lighting, subsoil conditions, drainage and irrigation, and solar exposure. They must specify construction details for attractive materials, plants and furnishings that are safe, green and durable. And fountains, ponds, retaining walls or other structures necessitate collaboration with engineering specialists.

Landscape architecture is challenging, in part, because so many design choices exist, and bad choices are easily made. For example, countless paving materials are available for "hardscape" areas, along with countless patterning options. Yet a hardscape surface not only must look good, it also must be stable and walkable -- even in stiletto heels. Many hardscapes have needed to be redone because of improper materials and installation.

Selecting trees, shrubs and ground covers is equally tricky. The landscape architect must consider sun and shade conditions, microclimate, topography, irrigation needs and, above all, seasonality and indigenous suitability of plants. In addition to making aesthetic choices, the designer must envision what plants will look like when they mature after years of growth.

Yet simpler requirements enable landscape architects to emulate painters and sculptors. With fewer practical constraints, they can more freely create purely aesthetic and symbolic effects. Whether earth or a roof deck, the surface being designed in effect becomes a canvas on which to deploy diverse elements and compose artful designs in two and three dimensions.

Washington is such a canvas, a place where historic open spaces have been designed by esteemed landscape architects. Elaborating on the original plan by Pierre L'Enfant, Frederick Law Olmsted and his son helped shape and reshape the Mall, still a work in progress. The late Lawrence Halprin of San Francisco designed the Franklin Delano Roosevelt memorial in West Potomac Park. And, just a few years ago, University of Pennsylvania professor Laurie Olin skillfully incised a curving, almost invisible walkway into the grass-covered knoll on which the Washington Monument sits, improving security at the site.

But the canvas of Washington displays one other unique, artful and environmentally beneficial attribute. Hundreds of thousands of trees and acres of parkland grace the city. Thus in many places the nation's capital feels less like architecture ornamented by landscape and more like landscape ornamented by architecture.

Roger K. Lewis is a practicing architect and a professor emeritus of architecture at the University of Maryland.

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