Mazza-watching has been something of a hobby of mine ever since the Gallerie of that name opened up on Wisconsin Avenue five years ago. The neighborhood was, as they say, ripe for development; Mazza's coming was much ballyhooed and oft-postponed, and then the building that finally did appear was, well, interesting, and has been getting more interesting ever since: It has been through its beige and its green periods and now is entering its age of black and white.

People lately have been given to writing me incredulous notes or stopping by my desk to ask, "Have you seen what they're doing to the Mazza Gallerie?" As the latest doings had somehow slipped me by and the reports were intriguing, I hastened to the spot for some Christmas shopping and a look, and was not disappointed: The new work is just as pretty and, in its way, as off-the-wall as the old.

The original Gallerie, designed by John Carl Warnecke Architects, was basically a big horizontal box filling out a full block on the west side of Wisconsin Avenue just inside the District line. The nicest thing about the box was its fancy wrapping -- a smooth, rich covering of warm-toned travertine panels neatly stacked in alternating horizontal and vertical rows -- so that it was a pretty box indeed if a bit outsized to be so lacking in bows, beads, stars, spangles or anything to make it more approachable.

The building, I presume, was supposed to say something like, "This is a swank, swell place, more than a bit above the common commercial run." Clearly, it succeeded. But for all of those elegant travertine planes, the clipped and cantilevered corners, the sleekly dramatic entrances, something was wrong. The building was too standoffish by far.

It is interesting to think about why. Although not completed until 1977, the building was conceived much earlier in the decade. Aesthetically, in its forthright expression of the basic geometric form, it is perhaps related to the mid-'60s style called Brutalism (though it should be pointed out that it bears some resemblance to your average warehouse as well), a by-and-large apt name for a style not known for its sensitivity to the street. Sensitivity to the city street was not, however, one of the big corporate architectural issues of the early '70s, which followed the riotous '60s as night follows day: Big projects like the Mazza Gallerie were as likely to want to protect themselves from as to embrace the chaotic urban surround.

Anyway, this combination of commercial, aesthetic and psychological snobbery apparently produced unfortunate mercantile results. Sales at the stores were said to be much less than hoped for; ownership of the project changed hands; old owners and new searched for remedial measures.

It was a "blind building," in the words of David Pesanelli, an industrial designer who, at one point, was called in to consult on the problem. "I'd have bet that if they had advertised a $10 giveaway, some of the people who came to get their money would have turned around and gone home -- 'Let's go home, Gladys, they're not open,' " Pesanelli said. He recommended a few low-budget steps as starters: lighting up entrances and what windows there were, providing signs to tell people where they might enter the structure, and marking the entrances with a bit of drama.

This was the fortunately limited period of the bright green look at the Mazza -- green signs and canopies that looked tacked onto the huge structure like the afterthoughts they were. But even these modest measures showed some results. "Traffic in the Gallerie did go up 43 percent after that," Pesanelli reported, "although the McDonalds opened at the same time, so we don't know whether we were responsible for 40 percent or 3 percent."

The building currently is entering its third major phase, far more ambitious and costly than the green period. Under the guidance of RTKL Associates, a large Baltimore architecture firm, much of the travertine around the front entrance has been replaced by glass; a row of new, larger trees has been planted underneath the handsome new iron tree grates designed by Albert Paley (the very same ones commissioned from him by the Pennsylvania Avenue Development Corp.); a new paving pattern has been installed outside, and the atrium space inside repainted, relit and generally spiffed up.

By far the more noteworthy change, the one that has everyone gawking and talking (and that may be the point), is the thin vertical black and white ceramic tiles used to re-cover surfaces at the corners and around entrances and windows. The tiles are sensationally beautiful, but the clash of travertine and tile has a lot of people confused and upset. (Several people have compared the place indignantly to a public bathroom.)

Basically it is not so much a clash of materials and colors as it is a contrast of architectural attitudes: the righteous orthodox modernism of the original box versus the sensuous vernacular sleekness of the new additions. Colors, tiles, glass blocks, all sorts of flat built-in decorations, have been making a substantial comeback of late--a happy turn of events, although whether a fraction of an existing modernist building is the right place for it is quite a question.

Obviously, the new Mazza Gallerie is an awkward pastiche, and in some details looks as if it had been designed by a committee of store owners. But so what? Many, many, many worse things have happened in Washington commercial architecture, and to see a lot of them one doesn't need to look far from the Mazza Gallerie, which is a lot livelier than it was as a serious modern box, and more appealing than the other new architecture in the neighborhood (which is not saying much), and better than almost anything around it except for a few 1950s structures and a downtrodden little terra cotta-covered Metrobus drivers depot.

The commercial neighborhood, in fact, being a sort of uncomely and somewhat dysfunctional combination of suburban shopping center and urban street network, is in more need of help than the Mazza Gallerie. In any case, anytime the owners of the Mazza want to spend a few more million ducats on yet another renovation, I have an idea: Punch a few more windows in the travertine, and cover the rest with city-slick tile.