Richard Haas is, in a way, a magician. An artist whose subject matter is architecture and whose work quite often is as big as buildings, he has forged a trademark career by solving architectural problems with nothing more than a sharp, fecund brain and layers of paint only a few millimeters thick.

Haas' latest feat -- the transformation of a nondescript 10-story sliver of a building in downtown Washington -- is now two-thirds complete. Even though the project is not finished, this is a fitting day for comment, it being the birthday of the president whose death gave the building its name and whose life, not coincidentally, Haas chose to celebrate in his latest murals.

The Lincoln Building, 514 10th St. NW, has been standing high above its low-rise neighbors (including, of course, the house where Lincoln died 120 years ago after being shot in Ford's Theatre, across the street) ever since it was built in 1923. But except for its height, and perhaps for the now ironic fact that during the late 1930s its upper floors served as offices for a number of the bureaucrats who helped support the muralists and other artists employed by the Works Progress Administration, the Lincoln Building has led a thoroughly undistinguished life.

Architecturally, it is plain and then some. Cheaply (but solidly) constructed of reinforced concrete, the building lacks ornamentation and any other outstanding features save the minimal, Chicago-like tripartite windows facing 10th Street. Interestingly, architect Charles Gregg did place wide industrial-type windows on the northern and southern facades, normally windowless in such midblock structures. It was as if, commented Elizabeth Miller in a history she compiled for the new owner, Gregg somehow "knew that the building would always tower over its neighbors."

Washington architect James Bayley, hired to renovate the building, said Haas' work "just naturally" occurred to him as he was struggling with the problem of how, on a tight budget, to give this unsplendid splinter a bit of rentable panache on the outside. "Except for two shallow vertical piers on the front, the building was entirely flat," Bayley explained. "With those high walls on either side, it seemed to call for a painted solution."

Bayley knew that Haas had done wonders with illusionistic, two-dimensional treatments upon such featureless walls in other cities. In Boston, for instance, Haas conceived a painting of a spacious Neoclassic interior for the windowless rear facade of the Boston Architectural Center; in New York he was able to place a painting of the original Times Tower on the side wall of a building near Times Square; and in Chicago he created a vast, fascinating four-sided mural, "Homage to the Chicago School," for a banal 20-story apartment house.

Haas' first work in Washington is not as spectacular as these pieces, but it is every bit as intelligent and appropriate to its place. It consists, so far, of murals on a south-facing sidewall and the east-facing main facade of the Lincoln Building, painted with skill by artisans of the Evergreene Studios of New York. A mural will be added to the northern facade when the winter weather breaks.

The murals improve the building by giving it a genuine feeling of three-dimensional modulation. The windows on the formerly unimpressive south wall, for example, now look as if they project outward -- as if they were bay windows thrown into sharp relief by a late-morning summer sun. Similarly, the front facade, where the narrow piers were painted to look as if they are decorated with shiny blue tiles, has been given an entirely new feeling of color and depth.

"I was surprised by the building at first," Haas said. "It's such a New York building, the way it sticks up there." He was also pleased by the opportunity to execute an idea he had experimented with "two or three times" without success -- to illusionistically "cut through" a narrow building by painting images of monumental, open spaces on opposite sides.

The south facade of the Lincoln Building today contains a "hole" through which we can glimpse, in the distance, a painted corner of the Lincoln Memorial. For the north facade, Haas will give us another image of the same space. Atop this perspective space, on the south, is a mosaic-like image of the young Lincoln, ax in hand. This will be complemented, on the north, by an equally familiar image of Lincoln as president, not long before his assassination.

Haas' first full-scale exterior mural was completed a decade ago, on the plain wall of a building near his studio in the SoHo district of Manhattan, painted to mimic the rich cast-iron fronts of its neighbors. Since then, his work has become increasingly sophisticated, as this Washington piece so clearly demonstrates: Haas takes what is given in a particular location. In color, style and spirit, right down (or up) to that somewhat cornball image of the young Lincoln, the murals take advantage of the stylistic traits, such as they are, of the building upon which they are painted as well as complement the qualities of nearby structures.

Bayley deserves credit, too. His shipshape renovations of the interior floors are just what was necessary to attract new tenants to the Lincoln Building, and the narrow, high-ceilinged new lobby he designed provides just the kind of minimal, Deco elegance the space requires. But most of all he rates kudos for his unusual perception that, in this particular case, someone other than he was better equipped to do a big part of his job.

Officers of the Wynmark Development Corp. are to be applauded for recognizing a good idea, even when it cost a bit more. (Architectural modifications he had planned for the exterior, Bayley said, would have cost about $35,000, while the murals will cost approximately $75,000.) As a result, they got a better product and Washington got an interesting new "building" on 10th Street.

Incidentally, the murals were painted with Keim Historisch paints, a long-lasting brand of paint (it unites chemically with any semiporous surface to which it is applied) developed more than a century ago in Germany to satisfy the vast decorative building schemes of Ludwig II of Bavaria. And though tall structures are sure to grow around the Lincoln Building in coming years, the adjacent properties are protected by height easements. Haas' handiwork should be with us for some time.