The Lexington has a comfortable, settled look, as if it has been standing on its downtown corner for many years.

There is something about the quietly traditional architectural style that makes one forget, for a moment, that the site the building now occupies so serenely stood vacant for what seems like ages, a symbol of the destructive turmoil of downtown's decline.

But the Lexington is indeed a brand new, 86-unit apartment building that is filling up pretty fast despite rents ranging from $1,000 to nearly $3,000 a month. It is only a piece fitted into the jigsaw puzzle of putting downtown together again--a little piece in a large, unfinished puzzle.

Construction cranes once again are towering over the old downtown--east of 15th Street NW, south of Massachusetts Avenue. The area is experiencing one of its periodic booms. Four or five large buildings are being built or renovated within easy walking distance of the Lexington site, which is the northwest corner of Eighth and D streets NW.

Other than the Lexington, however, none of these new projects is for permanent residents. One is a hotel--a Marriott Courtyard opening soon in the fine old Riggs Bank building at Ninth and F streets NW. The others are for offices, with provisions for some retail and entertainment uses.

In other words, the same old fight is still being fought, and by many of the same old players. The primary issue remains office space vs. residential development, and the powers behind office buildings again appear to be winning. The goal of a "living downtown"--the city's oft-professed official slogan for the area--is but a distant prospect, for it remains true that there can be no genuinely living downtown without people living in it.

Still, there is the Lexington. It is possible to stand on the corner of Eighth and D streets and imagine that the glass is half full, rather than three-quarters empty.

Immediately to the south is busy Market Square and the twin, becolumned buildings that frame it. With its mix of residential and office uses with a busy, successful public space, Market Square is a proud signal of what enlightened planning can accomplish. Beyond the square stands the National Archives, a symbol of the lasting strength the federal government lends to downtown's economy.

To the north, along quiet Eighth Street, there are fine old buildings with new uses--an arts center, a trendy restaurant and the old Lansburgh's department store, now an apartment building. Beyond the scar of a huge, long-vacant lot, the historic National Portrait Gallery stands as a noble reminder of the important role of the arts in downtown's past, present and future.

The Lexington fits beautifully into this pattern. Like every other recent residential building in the heart of the old downtown, this one owes its existence to the Pennsylvania Avenue Development Corp. (PADC), the powerful, innovative federal agency prematurely terminated by Congress in 1996. (Praise be, the General Services Administration took over much of PADC's unfinished business at the time and--so far--has been aggressively following through.)

Attracting permanent residents was an integral part of the official PADC plan for rejuvenating Pennsylvania Avenue and adjoining blocks in the Eighth Street area--in numbers, the goal was set first at 1,500 units, and then lowered to 1,200 units. The completion of the Lexington brings the total of units actually constructed to 831; a companion apartment building, a 47-unit sliver to be located on the southwest corner of Eighth and E streets NW, will bring the total to 878. Bids are being sought on a project to contain at least 345 more units.

Part of a large-scale mixed-use development, the Lexington was a long, long time coming. Guy Martin, the principal in charge of the design for the Washington office of Studios Architecture, still remembers the initial call on the project--15 years ago. At the time Martin was a partner with David Jones in Martin & Jones, one of the young Washington firms that flourished in the atmosphere of the early '80s, a time of renewed interest in historic styles and historic preservation.

In the early years, Martin recalls, the project advanced in fits and starts. It was held up for a long while as the developer, Kingdon Gould III, attempted to persuade Congress to amend the Building Heights Act of 1910, primarily to add a couple of floors to an office building that was, and remains, the main economic engine of the development package.

This would have been a terrible precedent and, thanks in large measure to adamant opposition on the part of the National Capital Planning Commission, Congress did not bite. (Ill-advisedly, both the City Council and the PADC supported Gould in the matter.) The recession of the early '90s put the whole project on hold until a couple of years ago. The office building, 11 stories high and stretching all the way from D to E streets along the east side of Ninth Street NW--more than 400 feet--will open this fall.

Initially, the idea was to develop very nearly the entire block along Eighth Street, requiring the demolition and relocation of a large Pepco substation. Unfortunately, this did not work out. The unpeopled substation, a necessary yet most unwelcoming type of building, still stands.

Though adorned now with 19th-century facade remnants saved and stored by the PADC, the Pepco building does indeed compare poorly with initial plans drawn up by Martin & Jones. These show the west side of Eighth Street lined with apartments--alas, a missed opportunity to shape a wonderfully urbane residential street.

The design changed a lot, too--but for the better. The Martin & Jones team gave Washington a number of splendidly spirited buildings of the early '80s--in particular, the wildly collaged Madison Bank Building at 29th and and M Streets NW, and the teasingly irrational Barclay apartment house at 25th and K Streets NW in Foggy Bottom. But the stressed postmodernism of the initial designs for the Lexington would not have worn particularly well.

By contrast, the final product, though a bit predictable, seems quite at home. It is a brick building of an old-fashioned sort, yet it does not seem in any way slavish in its evocation of the past. There is a sort of effortless-seeming grace in the transitions from bottom to middle to top, and the wide vertical bays, running from the fourth to 10th floor on the primary facade, are satisfyingly elegant--just as they should be.

This easygoing architectural quality doubtless influenced some of the renters to take the plunge. More to the point, however, the building's popularity indicates that there is a market out there for pricey, well-designed downtown housing. The success of previous residences mandated by the PADC has not convinced doubters. Possibly, with the Lexington, we are turning a corner.

And why not? Why should Washington be different from other prime cities? Downtowns, with their sheer busyness and their inimitable concentrations of cultural attractions, are the perfect places for certain types of people to live--well-off empty nesters, well-paid young professionals and rich folks in general. It is not for everybody, that is for sure--besides the prices, there are all sorts of reasons to stay away.

Even so, there are good reasons for those who do not or cannot live there to care about Washington's downtown. A vibrant center is an important key to regional economic health and to local pride. And the all-important key to making Washington's center healthy is having people live there. One could put it this way: More Lexingtons are needed.

CAPTION: For urbanites, the Lexington, a new apartment building at Eighth and D NW.

CAPTION: The lobby of the Lexington, which is attracting residents despite rents ranging from $1,000 to nearly $3,000 a month.

CAPTION: Room with an urban view: An apartment in the 86-unit Lexington, at Eighth and D streets NW, a site that long stood vacant.