There is ample reason to celebrate the completion of the vast remodeling job on the National Press Building downtown.

The foremost reason is simply that the building, significantly altered inside and out, remains in its historic location and is again in good economic health.

The corner of 14th and F streets NW has been a place where journalists have congregated since early in the 19th century. Though today's journalistic community is much larger and more widely dispersed, the press building, along with the remodeled and revivified National Press Club occupying its top two floors, is still an actual and symbolic center of this activity.

Past, present and future are joined in this building. Calvin Coolidge was present at the dedication of the original structure on "newspaperman's row" in 1926. Ronald Reagan will be there at the dedication next month of the renovated building. No doubt future presidents will find it necessary from time to time to make their heavily guarded way along the two short blocks that separate the building from the White House.

These aspects of Washington life distinguish it from the daily goings-on in other American cities. They are to this city what the hullabaloo of the Stock Exchange is to New York, which is to say they comprise an interesting attraction, a functional necessity and a symbolic confirmation of the city's place in the national scheme of things.

They have regional significance, too. If the Washington area is fast becoming a locus made up of numerous competing, though interdependent, centers of economic activity, it is important that the old, historic center retain its uniqueness and vitality. So, in a very real sense, the National Press Building is not just another office compound: It represents a crucial function that could not possibly be performed elsewhere. This building is inconceivable, say, in Tysons Corner.

In addition to its historical importance, as Mayor Marion Barry so ebulliently proclaimed Thursday on the occasion of the opening of 40 more retail stores on its lower floors, the rehabilitated building contributes a significant piece to the puzzle of reviving the old downtown district. The Shops at the National Press Building and the adjoining National Place now number 85, and in itself this is a big addition to the growing list of attractions in the old downtown.

Equally important, from an urban design point of view, are the linkages the new spaces establish for pedestrians. It will take some getting accustomed to, even for veteran downtown walkers, but it is now possible to enter the press building at 14th and F and to make one's way, in a zigzag procession of varied interior spaces, to the lobby of the J.W. Marriott Hotel and from there to the spacious table of Western Plaza astride Pennsylvania Avenue. Although hardly a shortcut, the route makes up in color and life what it lacks in directness.

In a sense this pattern follows the suburban prototype of the enclosed shopping mall. (One wishes that more of the shops in The Shops opened directly onto the street.) But even if one feels a certain disorientation inside The Shops -- it's Boutique-Eatery City, Anywhere, U.S.A. -- there is a difference. When one leaves this mall one immediately engages the city's sidewalks and streets rather than a vast parking lot, and since these particular open spaces are among the more recognizable and breathtaking Washington has to offer, this is no small difference. The Pennsylvania Avenue Development Corp., which insisted on these intricate pedestrian connections, is to be praised for its foresight.

Architecturally, the principal thing the "new" building (actually a new skin on the old bones) leaves to be desired is a sense of memorable identity -- some quality about it that would say "National Press Building" to passers-by in no uncertain terms. There remains some discussion concerning an electronic news band on or above the glass and metal canopy at 14th and F, but one gets the feeling it is too little, too late. These are the kinds of concerns that should be built into the design process at the beginning instead of being tacked on at the end.

Otherwise, the design of the building is a reasonably polite job -- a bit top-heavy, somewhat heavy-handed in detail, but not inordinately offensive. "We wanted to make an effective transition between the exuberance of the Willard Hotel and the sleekness of National Place," explains Edwin Schnedl of HTB Architects, and one can clearly appreciate these intentions -- in the building's granite base, brick middle and protruding precast concrete top, and in details such as the abstracted brackets supporting the 13th-floor balcony -- without being overly impressed by the results. The happiest note on the fac,ade is the giant decorative niche of the old Capital (originally the Fox) movie house, which was sensibly retained to become a distinguished punctuation mark along F Street.

Schnedl and his colleagues had to work within impressive limitations, and they coped with ingenuity if not inspiration. In the first place they were faced with the problem of remodeling a building in its entirety while keeping it operable in part, and to this end they came up with an efficient four-stage construction process. They also devised space- and time-saving solutions to other difficult problems, for example, stringing pipes top to bottom inside brick pilasters instead of punching them through existing floors.

The centerpiece of the new building is a 15-story skylit atrium. To build it, the architects used the light well of the original structure and broke through the seven floors of offices that, in 1964, had filled in the spacious (3,000-plus seats!) auditorium of the theater. The resulting space is tight but not lacking in interest.

I particularly like the concrete forest-like effect of leftover, and structurally necessary, columns just inside the F Street entrance, and the squeezed, packed effect of the whole. I particularly dislike the fire coating sprayed onto the massive steel trusses, now exposed, that once supported the roof of the auditorium. The coating is gray, porous-looking stuff, and it makes the muscular trusses appear as if they had been made of foam.

A bad decision was to continue, in the press building atrium, the motif of Caribbean blue cylindrical columns established in The Shops at National Place. This was done, Schnedl says, at the insistence of the Rouse Co., which manages The Shops and which clearly wanted visual and thematic continuity. But it robs the new atrium of what should have been a unique visual character. "I wish we hadn't given in on that," Schnedl says ruefully, and rightfully so.

On the top two floors the new National Press Club quarters are handsome and commodious. Best of all is that even though the club's facilities have been greatly expanded, the spaces retain much of their old, smoky, slow-moving, wood-paneled charm. It is comforting to know that reporters and editors still occupy most of the offices in this building, and still gather in the club before, during and after work.

Maintaining such links to the past is important to a city in more ways than one. The idea of historical continuity provides the underpinning for Washington's image of itself as a national and world capital -- a place where news continues to be made.