Thursday, Washington's Joint Committee on Landmarks will consider the fate of my good friend, the Demonet building.

The first time I walked down Connecticut Avenue, some 25 years ago, I was struck by the way this small, pert townhouse, all tower and dome, quietly commands one of the busiest corners in Washington, the bustling confusion of Connecticut Avenue, Rhode Island Avenue and M Street.

I continue to admire friend Demonet every time I pass it, which is often.

The building's self-assured nobility makes it seem more prominent than its proletarian 10-story neighbors. The worn whitewash over its fanciful brickwork does not detract from its elegance. The shabby firestairs and storefront mar its dignity no more than a frayed collar mars the dignity of an aged aristocrat.

It seems redundant to ask that the building be declared an official landmark, as historian Alison Luchs has done in an eloquent application on behalf of the Dupont Circle Citizens Association and others.

The Demonet building is already a landmark, a self-made landmark, if you will. It should be all means be preserved.

I cannot claim that my friend has any special provenance. We don't even know who the architect is. The Demonet was probably designed by its builder, John Sherman, who received the permit for it on April 23, 1880. He built it as townhouse at first, part of an elegant row close to what in those days were the outskirts of town.

At the turn of the century, however, as the capital grew with the nation's manifest destiny, Connecticut Avenue changed from a residential boulevard into a commercial one, thought of as somewhat like the Rue de la Paix in Paris, Bond Street in London, or Fifth Avenue in New York.

In 1904, Jules Demonet, too, turned his corner townhouse into a shop. It sold confectionary, ice cream and candy, which his family had been producing for 56 years to the delight of presidents and high society. The famous Demonet caramels are still being sold at Avignone Freres.

Nor can I claim that the old candy store, though an architectural confection, has unique architectural distinction. It is the product of that once disdained but now much admired period which deserves a better label than "late Victorian eclectic."

It was the gaslight era. (The first electric street light appeared in New York the year the Demonet was built.) Morality, or rather the preachment thereof, was confined to human behavior and not, as at the Bauhaus, to architectual design. With sinful, exuberant romanticism, architects, builders and the makers of prefabricated building parts, stole and recklessly mixed any and all architectural or ornamental styles that pleased their eyes and whim. Like fruitcake, the concoction was mostly delicious.

There are thousands of gaslight-era houses in Washington. They make it a livable city. The Demonet's special distinction is only that, to mark the corner, it features an octagonal tower, topped by a ribbed tin dome whose design was unabashedly appropriated from Filippo Brunelleschi's marvelous masterpiece, the dome of the Florence Cathedral.

Today, this astounding plagiarism would be considered immoral. Architects must be original, no matter what. The sophisticates of the gaslight era, however, thought architectural plagiarism clever. Today, the dome also seems but a minor echo of the St. Matthew's Cathedral dome across the street. The fact is, as Alison Luchs noted, that St. Matthews was built 13 years later.

Why then, if neither overwhelming historic significance nor unique architectural distinction can be claimed, should my friend be allowed to stand in the way of "progress" and profit?

Nostalgia - whether for gas-lit candy stores or candle-lit Colonial taverns, let alone for such miserable remnants thereof as the Rhodes Tavern opposite the Old Treasury Building - is not enough to enlighten the planning and building of lively and livable cities.

What makes the Demonet irreplaceable is that it reminds us that Connecticut Avenue is not only a slick shopping street like any other but also a distinguished address.

More important is another factor which is rarely considered in American city planning and which transcends architecture or history. That factor is urban design - the way individual buildings, historic associations, modern needs, building mass and open space, traffic flow and street signs, all come together to attract or repel us, to make us feel good or bad.

So when the Demonet building, which is case number 79-3, comes up, I hope the Landmarks Committee members will close their eyes for a moment and imagine what that corner of Connecticut Avenue will look like if the mini-Brunelleschi were replaced with a bland 12-story box - or even an interesting 12-story box.

It will look like K Street, that's what it will look like.

Who cares?

I was asked that question the other day when I pleaded another historic preservation case, the retention of the Beaux Arts terra cotta facades on the Keith building opposite the Old Treasury.

It is not an easy question to answer.

"Who cares?" is what people say who toss candy wrappers on the street and beer cans on the highway. "Everybody does it."

Well, not quite everybody. America is not only littered minds, littered by popular causes, fads, obsessions and the freeways of least resistance.

It is also people who care even when they think no one else does.

The D.C. Superior Court ruled that the developer had a legal right to tear down the Keith, terra cotta and all. But chances are he won't. Enough people cared to give him pause. He announced the facade will be retained.

And enough people care, I should think, to warrant giving case number 79-3 very serious consideration.

No living architect, not even a joint venture of I. M. Pei, Philip Johnson, Kevin Roche, Chlothiel Woodard Smith, and Skidmore, Owings and Merrill, all working together, could achieve the elating and redeeming charm, the masterful urban design effect that my old friend Demonet achieves.

The building should be restored to some profitable use. One of them might be an elegant, European coffee house, where you might meet friends, buy patisserie and such on the ground floor and sit and sample it, upstairs, along with coffee, tea, other potables, Schlagoberst, light luncheons and suppers. There might even by gypsy music.

Demonet could become what the Cafe de la Paix is to Paris, the Sacher to Vienna and the Kranzler to Berlin.

At any rate, the building is a landmark. It should officially be recognized as such. We need it.