Downtown Silver Spring, its glory days as a new idea in suburban living long gone and its future still uncertain, works a faded charm upon connoisseurs of architectural time warp.

There is something awfully appealing about a place where dusty leftovers like the K-B Silver movie house on Colesville Road and the Tastee Diner on Georgia Avenue can be treasured, at least while developers strive to get their building blocks in order. And the appeal is more than just happenstance history or simple nostalgia.

The Silver Spring shopping center was built more or less of a piece in the mid- to late-1940s. Neither parking lot fever nor the listlessness of age completely hides the architectural virtues of the buildings that spread a few blocks to the north, east and south from the Colesville-Georgia intersection.

In a curious fashion, this cluster of buildings looks better than ever today. Partly, this is because the buildings, though of varying heights, are basically modest and low. When they put the place together the merchants, builders and architects were not trying to reproduce downtown Washington. They wanted to be suburban, and they succeeded.

Mostly, though, this is because today we are better situated to appreciate the coherence and liveliness of the architectural style. There's nothing all that flashy about these buildings, now four decades old, nor anything all that ambitious. But there is color in panels of glass and tile, in striped brickwork, in once-shiny aluminum signs and trim. There is a modest, late-Deco decor in the fluted pilasters and rounded corners, and a sense of play in forms such as a stepped chimney or a bank sign that doubles as part of a building fac,ade. And there is an overiding sense of civility, a willingness to stand out a little, but never too much.

To be sure, Silver Spring is far from paradise. More often than not its weary storefronts are marred by hapless attempts to rejuvenate. The down-scale retail mix, least to say, lacks contemporary spark. To walk there can be hard on the nerves. In phalanx formations, the cars seem to run right at you on the wide through streets. Recent architecture has not been kind. The best of the newer buildings are bland. The worst are aggressively banal, in the Rosslyn way. They took the high northwest horizon like an approaching horde in the late 1960s.

But at the very core of the retail center there is something--an ensemble of buildings of a certain style and spirit--that is very much worth saving. Things do not seem to be going that way, although fortunately there is no building boom to pose an immediate threat.

There is, however, one brand new addition to the Silver Spring skyline, a ribbon-window speculative office building at 1100 Wayne Ave., two blocks from the town center, west of Georgia Avenue. Not so long ago in this column, I referred briefly but disparagingly to this building. Developer Lloyd W. Moore and architect Charles E. Hall Jr. of Ward/Hall Associates wrote to protest, in Moore's words, that my "selection of 1100 Wayne Avenue as a case for dullness was unfair."

They were right, up to a point. There is no question that the Silver Spring central business district, as defined on the Montgomery County planning maps, needs private money to bring new life. Moore took a praiseworthy risk: His building is the first major new structure to go up in Silver Spring in many years, and the first in the disorienting zone between the Metro station and the retail center.

A closer look at the new building, which replaced a surface parking lot about halfway between the rail and bus depots and Georgia Avenue, clearly was called for, because its good points are concentrated almost entirely where the building meets the street.

There is about a 15-foot change in grade on the site, a fact Hall used to provide two interesting covered walkways. These do double duty as entryways to the restaurants and shops on the first two floors of the building. Changes in color (from gray aggregate facing to white surfaces) and in fenestration (from dark-tinted ribbon windows to floor-to-ceiling clear glass panes in 4-by-4 or 2-by-2 patterns) also help to give an attractive side to Wayne Avenue, a street rudely widened in the early 1970s.

The lower corner of the building is perhaps its most attractive feature, a little Paley Park in Silver Spring, with trees and a slab fountain, and benches and tables soon to come. Paley Park, of course, is an oasis in midtown Manhattan. How well it takes in Silver Spring remains to be seen. Moore, in any case, promises a lively restaurant for the spot.

Most of these improvements resulted from negotiations among the developer, the architect and county planners. As welcome as the improvements are, there is no escaping the fact that 1100 Wayne Ave. has a personality split three ways: a string of shops at ground level, a parking garage for the next three floors, and above that a spec office building of far-too-familiar type.

The best that can be said of its massing is that it helps to hide a ghastly 1,800-car parking garage from street-level view--not exactly a small point since Silver Spring's bulky public parking lots, uniformly ugly but in different ways, are a study in visual blight. The best that can be said of its fac,ade treatment is that the architect made a few minimal, very minimal, gestures in the right direction: an arched entranceway, a slight change in window patterns to mark the building's center, a solitary notched corner.

The building raises a number of issues to concern anyone interested in Silver Spring. One is the blindness of the developer and architect to the ingratiating style and modest scale of the existing fabric of the place. Another is the sheer size of the building. The official plan for the area announces that "the retail center should be strengthened and enhanced," but zoning regulations permit building densities way out of kilter with what is there now.

The area actually was down-zoned a few years ago, but not enough. The new regulations encourage the oft-demonstrated inclination of developers to build big by the carrot-and-stick method of negotiated "amenity packages," which always add density to a project. Following this pattern, Silver Spring could become a place with lots of amenities and very little character.

If the Wayne Avenue building represents the design future of Silver Spring in these respects, then we can start preparing a fond farewell to the old place, with all its civility and good humor. The trouble is, it probably does.