In the opening paragraphs of his book about the design and development of atrium buildings, architect Richard Saxon states that "the skyscraper was the result of a technological breakthrough -- the safe elevator. No such simple technical trigger can be found for the rise of the modern atrium building: A larger number of influences came into play . . . influences of a strength that promises to make the atrium building one of the generic building forms of the late 20th century."

Yet in Washington, D.C., some of these influences are not at all contemporary. In fact, decisions made when the city was established at the end of the 18th century, coupled with urban design policies adopted by L'Enfant's patrons and successors -- from Washington and Jefferson to the Congress and city commissioners of the early 1900s -- reinforced the potential appropriateness of atrium buildings.

L'Enfant's plan created blocks 300 to 500 feet wide permitting buildable parcels with substantial dimensions. Geometric interaction between the diagonal avenues and the rectangular street grid produced trapezoidal or triangular lots of considerable breadth. Building height policies, which first were advocated by the city's founding fathers to preserve access to sunshine, skyview and fresh air, kept D.C.'s skyline low and horizontal. And the city's citizens and governments repeatedly have rejected the towering skyscraper made possible by Mr. Otis' elevator.

Thus Washington's buildings still can reach heights of only 60, 90, 110, 130, and, along Pennsylvania Avenue NW, 160 feet. In addition, 20th-century zoning regulations limit floor-area ratios and, in many zones, percentage of lot coverage. Therefore, even when legally permissable building volumes contain the maximum allowable floor area, they do not necessarily have to cover all of the site to the full height limit.

With a sufficiently large site, these urban design traditions and parameters mean that the architect typically has the option of carving away parts of the hypothetical full-height, full-coverage volume to create yards, exterior courts, a shorter building or an atrium. Rarely forced to choose between low-rise and high-rise building forms, designers instead must choose among optional "carving" strategies.

Flying over Washington, you see this pattern of design choices in the building shapes that occupy and control sites. Many have a kind of alphabetic character in their plan footprints. Atrium buildings can be thought of as block letter O's, or as several O's linked in buildings containing more than one atrium. Other buildings, embracing exterior courtyards rather than interior ones, are configured like the letters C, E, H, I or L. Still others fill their sites entirely without associated, embraced spaces.

Among the observable atria, some are open to the sky, others roofed. Transparent roofs act as skylights for spaces below, while relatively opaque roofs barely disclose what's under them. Some atria start at ground level, and some penetrate downward only a few floors.

Plants and people occupy a few open courtyards, but others are just paved service courts filled with vehicles or equipment. Many unroofed atria, empty and lifeless, only provide light and air to interior office spaces. They have no connections with the streetscape or with public lobbies inside. Many of this type are federal office buildings.

Among the oldest buildings in Washington with courtyards are the Treasury Building, begun in 1836, and the Old Executive Office Building, begun in 1871. Flanking the White House, each encloses a pair of similar unroofed atria that do no more than create additional facade surface area for the placement of office windows. Treasury's north courtyard is filled by a huge cube of air conditioning equipment. Hidden from the outside world, these courtyards are introspective, private realms.

In great contrast stands the old Pension Building on F Street NW, between 4th and 5th streets, now housing the National Museum of the Building Arts. Designed by Gen. Montgomery C. Meigs and built in the 1880s, its roofed atrium was intended to be a grand and imposing public room where people could wait, work, assemble or celebrate. The atria's presence behind the derivative Palazzo Farnese facades is suggested only by the uplifted, sloping, gable-ended roof forms whose ridge lines run both east-west (the building's long axis) and north-south.

With impressive overall dimensions (200 by 400 feet), the building has only four entrance doorways, See LEWIS, E30, Col. 1 each located centrally on the building's (and the atrium's) long and short axes of symmetry. One enters through a one-story foyer space to arrive at the edge of the atrium's surrounding arcade. Only then can one begin to comprehend the scale and magnitude of the space, and only then can one proceed to other destinations within the building. Once inside, anyone using the building must interact with the atrium continually, even when going to the rest room or to the elevators and stairs imbedded in the perimeter layer.

The Pension Building's interior grandeur resulted partly from a desire to show architecturally the nation's respect for its Civil War veterans. But according to Smithsonian architectural historian Cynthia Field, Meigs' notes show that he also was very concerned with the environmental comfort of those working in the building. The pragmatic general considered natural light and fresh air essential for good health, and healthy workers meant less sick leave and increased productivity.

Consequently, the atrium served as a giant plenum for ventilating and lighting the whole building. Double-hung clerestory windows encircling the atrium roof's perimeter could be opened and closed by a chain-and-pulley system. In the summer, natural drafts pulled fresh air in through open exterior office windows as warm air inside was drawn upwards and vented out through open clerestories. The same draft-inducing effect pulled winter's air warmed by perimeter radiators through offices and into the atrium.

Natural daylight suffusing the lofty space filtered down into the surrounding galleries and offices. Thus, work areas received light from two sides, the outside window wall and the atrium. The effectiveness of these ventilating and lighting tactics was enhanced by the unusually high ceilings (about 20 feet) of the building's three levels of offices, and by the always-changing dawn-to-dusk quality of the light itself.

The colonnaded, arched galleries lining all four sides of the atrium constitute the public corridors. Eight gigantic, 80-foot Corinthian columns in two rows, surmounted by semicircular arches, help support the clerestoried roof and divide the atrium visually into a major central space flanked by a smaller space at each end. The columns, each made of 85,000 bricks plastered and painted to look like marble, are taller than the columns at Baalbek in Lebanon, the largest ever constructed by the Romans.

The Pension Building's atrium, one of Washington's biggest rooms, is well suited to the pomp and circumstance of the many inaugural balls held there. Its use for such celebratory purposes was clearly intended by Meigs, who installed gas lights for nighttime events. A tiled fountain in the atrium's center and benches for waiting veterans further confirm the plurality of purpose for which the building and its atrium were conceived.

E. J. Applewhite, in "Washington Itself," claims that the Pension Building "is quite efficient despite the great open courtyard that creates a building essentially hollow," and that more than 80 percent of the total floor area "is available for useful office space -- an exceedingly high ratio even by the meanest of today's standards." Evidently, this fact has been rediscovered by today's well-meaning architects and developers.

NEXT: The atrium proliferates