James Renwick said that "the business of an American architect is to build something that will stand and be fairly presentable for about 30 years." Then what?

He didn't know that the 1981 tax law would permit a building to be declared economically dead after 15 years, and even sooner for restored historic buildings. Was he predicting a future of accelerated write-offs for architectural styles?

The label "puralistic" fairly describes what we see happening in architecture today -- pluralism in materials, coloration, geometry, decorative motifs and overall style. Robert Venturi's 1966 advocacy of "complexity and contradiction in architecture" would take hold in Washington, a city that was never really pleased with modernism's earlier advocacy of universal, culturally neutral, international styles of design.

Yet even while the phrase "postmodern" was being coined and popularized, many buildings of recent vintage continued to weave the threads of modernist tradition with more current ones. These "late" modern buildings make few premeditated allusions to antiquity or antique styles.

Along the Mall, I. M. Pei's National Gallery of Art East Building (1978) exemplifies one of these modern directions. It's a building shaped by objective forces -- site configuration and function -- and by its architect's willful imposition and manipulation of an ordering system of solid, pristine, enveloping geometry. In massing and color, the East Building relates to its context, but it is clearly cut from a stylistic cloth radically different from most of its neoclassical neighbors.

The continuing modernist use of megageometry isn't limited to the Mall. It works for office buildings as well as museums. Consider Vlastimil Koubek's International Square occupying the block bounded by 18th, 19th, I and K streets NW. Its horizontal bands of flush windows and concrete spandrels, plus its bottom collonades and receding, cut-away corner entrances, typify the tight-skin, carved-solid approach to building design.

Many other buildings sharing this compositional strategy have risen both downtown and in the suburbs: Look east of 15th Street, at Tyson's Corner, or in Bethesda. Banded in glass, brick, smooth-cast stones, metal, or precast concrete, they all seem to have begun conceptually as homogenous, regularly shaped solids. Portions then are sliced away or gouged out. These voids may reveal the structural skeleton and create monumental, recessed porches that may or may not invite entry.

Still making use of the slick, taut-skin approach with its Bauhaus origins, some architects have added more color or materials to create distinct facade patterns transcending functional necessity. Sometimes, such walls are relieved subtly by indentations or minor changes of plane in otherwise flush surfaces. This has become increasingly easier to accomplish with the advent of sophisticated curtain wall detailing and chemically exotic sealants that allow exterior butted joints and totally interior mullions for the support of glass or other materials.

Downtown at F and 13th NW, Frank Schlesinger and Mitchell/Giurgola designed National Place's office building with a flush north facade composed of bands of glass block, clear glass, brick and concrete. The blend of four materials, instead of the usual two, animates this otherwise planar surface through subtle variation of both color and texture. Instead of a giant, gouged-out loggia or collonade, the building's base and entrances are marked with a glass canopy paralleling the sidewalk.

Scores of taut-skin buildings line highways and major roads in the metropolitan area -- the Beltway, I-270, Georgia Avenue, I-95, the Dulles access highway -- making them high-speed exhibits of high-tech architectural compositions. Many of these structures likewise use more color, material variety, surface figure effects, and volumetric articulations to create billboard buildings that otherwise might go unnoticed.

A contrasting late modern style is represented by Washington office buildings whose exteriors are fashioned by extending patterns of structure from inside to outside, a precedent established by Louis Sullivan nearly a century ago in Chicago. This tactic can impart great depth to facades, to which additional layers and detail can be added.

Rather than using wrap-around ribbion windows expressing and emphasizing the stacking of horizontal floors, these facades call attention to the cellular, bay-by-bay nature of the infill between strongly expressed floors and columns. Their gridded elevations pay equal homage to verticality and horizontality.

At Connecticut and L NW, above the Metro entrance, you see this expression in the brick and glass Connecticut Connection office building (1980) designed by Skidmore, Owings & Merrill. The Federal Home Loan Bank Building (1978) at 17th and G NW, designed by Max O. Urbahn, exploits an exposed frame disengaged from its set-back glass skin to achieve shadow-casting relief.

Hartman-Cox's brick, concrete and glass Dodge Center (1976) in Georgetown and beige, black and glass National Permanent Building (1977) at Pennsylvania and 18th NW illustrate ambitious variation in the use of externally announced building system patterns (including mechanical ductwork at National Permanent) to generate facade depth and scale for large buildings. Dodge's walls slope back from bottom to top, while National Permanent exhibits sloping surfaces only at its Mansart-like roof.

Arthur Cotton Moore has concocted a lineage of buildings aspiring to something between modernism and postmodernism. Near the intersection of the Beltway and Route 50 intersection in Prince George's County is an office building partially curtained with brick, partially with dark panels of glass and metal. The brick's role as an applied veneer is clearly evident; it appears to have been cut out and glued on, over and around the building to render its profile and elevation more complex.

Moore goes for even more in his office building at the southwest corner of 14th and I NW. Multiple materials and colors abound, floors and wall planes advance and recede, window strips change size, curved walls contrast with straight walls, and balconies and terraces appear and disappear. Much of the building's northeast bottom has been excised to make a sort of lofty, hyperscaled grotto over the Metro entrance.

Still transitional from late modernism to postmodernism is Hartman-Cox's office building next to the concrete and glass University of the District of Columbia at Connecticut and Van Ness. These juxtaposed projects, similar in building mass and basic color, differ considerably in use of materials, secondary colors, detailing and urbanistic intentions.

UDC is monolithic and monochromatic, with minimal facade differentiation from one mass to another or one facade to another. Its buildings relate more to each other than to the streetscape. On the other hand, the office building is shaped to hold both the street/sidewalk edge and the Metro plaza as it steps down in height from north to south toward the entrance.

Although its exterior wall is basically a flush, beige brick and glass curtain wall, red brick stripes race around its volume, and lower floor windows and storefronts facing Connecticut are deeply recessed. Red-painted columns, beams and pendant lintels serve ornamental purposes. Without being literal, it recalls Art Deco, classical and neighborhood motifs all at the same time. But it is still a modern building.

Meanwhile, the taste for literal historicism was intensifying. Nostalgia, wit and whim, technical wherewithal and, ironically, the tax laws were inspiring several new historicist subisms: old facadism, the incorporation of existing, venerable facades in new buildings; new facadism, making new facades look like old ones; and fragmentary facadism, using only pieces -- whether new or old -- as part of new facades. D.C. was setting new architectural precedents galore.

NEXT WEEK: Facadisms