In his 1926 treatise on the "Five Points of a New Architecture," the great Swiss architect Le Corbusier announced, breathlessly, that "reinforced concrete has revolutionized the history of the window . . . windows, without interruption, can run from one end of the fac,ade to the other."

In 1922 and again in 1928 the great German architect Mies van der Rohe, as part of his proselytizing for a new urban order, published theoretical designs for low-rise office buildings along prominent Berlin streets -- sleek, horizontal affairs with alternating bands of concrete or steel and glass.

In 1985 downtown Washington is threatened by an inundation of buildings that fit Corbusier's dictum and Mies' sketches. Besides being 60-year-old cliche's, these buildings are exactly the wrong things for the fast-rebuilding old downtown. Once an exciting discovery and an emblem of the avant-garde, the ribbon window has become a curse upon the capital city.

If you stand, for example, on the southeast corner of 14th Street and New York Avenue NW and look toward the northwest, you will see three recent strip window edifices on as many blocks. It is not difficult to imagine the spaces between these buildings, now occupied by more or less nondescript low- or mid-rise structures, being built up in a similar manner.

This decidedly unenticing prospect, the architectural equivalent of turning a crucial part of the city into a sensory deprivation zone, can be repeated throughout the old downtown, an area where curious and instructive contrasts abound -- contrasts between the old and the new, between the new and the new, and between what used to be and what is.

On the northeast corner of 14th and H streets, for instance, stands a picturesque 1920s office tower that is as fine a local example as still exists of the art of polychrome terra-cotta ornamentation. Right next to it on H Street stands a new structure (designed by the Washington office of Skidmore, Owings & Merrill) that, because of its size and its dark window banding, fails dismally in its effort to be a modest, midblock building.

On the southeast corner of 14th Street and New York Avenue there is an unhappily average new strip window structure. Right next door, to the east, begins the sweeping curve of 1300 New York Avenue NW, as huge and in many ways as distinguished an office building as has been recently constructed in Washington. Here the architects (again, the local S.O.M. office) made a clear old-fashioned effort to give the building a base, middle and top, and they tried with some success to vary the window patterns and to give the fac,ade texture and depth. This contrast is symptomatic of the ongoing battle of architectural styles in the downtown area, and there is no question that 1300 New York Avenue is by far the superior product.

On the northwest corner of 14th and New York stands a new, banded structure (designed by the firm Weihe Black Jeffries Strassman and Dove) that occupies an entire block between the avenue and H Street. This aggressive basic box, despite its clean lines and its curved corners, suffers immensely by comparison to the TransLux Theatre and office complex, the spirited Art Deco composition that used to dignify the space. The comparison suggests that, inasmuch as we are tearing down huge pieces of the old downtown to make room for larger structures, we have a duty, at the very least, to make the new pieces as interesting as the old.

There are exceptions, both old and new, to the general rule that ribbon window designs are bad for D.C. The prewar Hecht Co. warehouse on New York Avenue NE is a local masterpiece of the Moderne style. In the heart of downtown the building facing Farragut Square on the north side of K Street, is, with its nicely detailed window bands of 1950s green glass and its calm limestone facing, a perfectly urbane postwar addition to the cityscape.

Among newer buildings, there are International Square (Vlastimil Koubek, architect), with its handsome poured-in-place concrete detailing, its attractive street-level storefronts and its sophisticated urban connections (the shop-filled interior atrium, connected to the Blue Line, is a natural shortcut); and 4215 Connecticut Ave. NW (Hartman-Cox, architects), where the ribbon windows, unlike most recent examples, are sliced neatly into fragments and set within an overall striped brick facade pattern.

The point to emphasize about these exceptions is that the architects and their clients didn't just wrap their buildings in bands of glass -- they had to go to some trouble and expense to make the product both interesting and good. As Hartman-Cox partner Warren Cox says, "To do ribbon windows well, you have to get out your Art Deco books. Those architects really knew how to do this stuff."

Many reasons for the strip window attack upon downtown D.C. have little to do with architecture. Shalom Baranes, an architect who has made a specialty out of sympathetic additions to historic downtown buildings (e.g. the Bond Building and the Army-Navy Club, both under construction), points out that standards established by the Washington Board of Realtors make developers pay an economic price for window indentations. (The formula is complicated, but fundamentally it says that a developer can claim more square feet of rentable space if the outer wall is flat.)

"This can mean more than 5,000 additional square feet per floor on a typical downtown building," Baranes says. "If a developer really wants to utilize every possible square foot, and thinks esthetics will make no difference, then you get the flat surface." Obviously this helps to account for the increase in the number of speculative strip window office buildings in the city: They are the safe, easy way to build.

Thomas Wilbur, of the John Akridge development firm, points to another reason for the ribbon window: Tenants like it. "They want light and they want views, and every inch of window you can provide, the better off you are from a marketing standpoint."

There are technological constraints, as well. Philip Esocoff, an architect with the firm of Keyes Condon & Florance and an admirer of the early strip window, notes that the glass in the earlier buildings consists of single panes, many of them operable, as opposed to the energy-saving, sealed double glazing that now is standard. It takes much heavier mullions to hold the double-glazed units in place, with the predictable result that for the most part the newer windows are much less appealing.

"A lot of those early modern buildings with their curtain walls and strip windows looked fragile, as if you could shatter an entire wall with a single rock," he says. "They looked like marvels because of this tension. But the newer buildings are like a guy wearing reflective sunglasses -- they look impenetrable and hostile."

As Esocoff suggests, none of these economic or technical reasons make more palatable the strip window buildings of the type now proliferating in downtown D.C. The reasons why these buildings are bad remain valid.

Washington, blessed with a height limitation, is by definition a horizontal city with a few spectacular and symbolically important vertical marks. Ribbon windows overemphasize this horizontal character to the point of utter boredom.

Washington, a city that used to be filled with a variety of very low, narrow buildings, is becoming a city of huge projects. The larger a building, the more it needs the art of architecture at its bottom, middle and top to disguise its offputting size.

Washington, a city of beautiful light, needs softness and subtle textures in its buildings to catch and to articulate this light. Flat ribbon window boxes blindingly reflect the light and each other, and, in so doing, make foreground objects out of buildings that should stay modestly in the background.

It has become all too obvious that the freedom young Corbusier foresaw in the idea of uninterrupted strip windows has become a straitjacket (a fact he recognized in his later works). Similarly, those early Mies drawings for Berlin, so beautiful in their pristine purity, have lost their ability to astound. Profoundly antihistorical, they have become stark antiurban symbols. Implying a brave new world, they have become frightfully banal realities. As such, they deserve no place in our city.