The official prose of ambassadors, with its diplomatic kindnesses and polite sidesteppings, is seldom to be taken at face value.

But yesterday when Swedish Ambassador Jan Eliasson said that he was "proud to be making a contribution to Washington's beauty," he could point to hard evidence of sincerity and truth -- a model and drawings of the embassy his nation proposes to build alongside the Potomac River.

If built as designed by Wingardh Architects of Sweden, the embassy would become an instant landmark, a simple yet sophisticated symbol of internationalism and openness on one of Washington's loveliest and most visible sites.

Referred to by Eliasson and others as "The House of Sweden" because it will contain exhibition areas, an auditorium and conference facilities in addition to everyday embassy activities, the building is to be situated on a privately owned lot facing the river in eastern Georgetown.

Immediately to the west of the new project site, just across 30th Street NW, stands Washington Harbour, Washington architect Arthur Cotton Moore's ebullient, if over-the-top, mid-1980s effort to bring urban life to the riverside. Immediately to the east is the National Park Service's homespun Thompson's Boat House. Rock Creek meanders close by on its way to the Potomac.

The 70,000-square-foot building is the southern half of a two-building complex being proposed by a development team made up of Novak and Sons of Washington and Armada-Hoffler of Chesapeake, Va. The Swedish government will lease the commodious basement as well as the first two floors of the four-story building. Luxury residential units will fill the top two floors. The other building, immediately to the north, will house offices and more residences and is to be designed by Moore.

As envisioned by chief architects Gert Wingardh and Tomas Hansen, the new embassy can be seen, on one level, as a straightforward container, a rational box. The design ingeniously accommodates all of the embassy's needs and adapts both the sloping site and natural surroundings to its advantage.

On another level, the architects are aiming for a bit of magic. It will be a great pleasure to attend an exhibition there and look out at a spectacular Potomac sunset from the glass-enveloped first floor. It'll be a treat, too, simply to pass by the building during a walk alongside the Potomac or to see it from a distance, especially at night when it is lit up, says architect Wingardh, "like a wicker lamp."

Basically, the architecture is a highly particularized version of that old modernist dream, the glass box. What makes this box specific to its time and place are subtle adjustments to functions and site, the intended quality of materials and finishes, and the aim to create a rare ambiance of natural and artificial light.

A visitor approaching the building from the riverside, for instance, will immediately register the wood-sheathed, cantilevered balcony that wraps the building at the third-floor level like a belt. It separates the public, or embassy, part of the building from the private, residential part. A visitor who goes inside will instantly be lured to an overlook that reveals how gracefully the building steps down the hill to a glass wall and platform facing Rock Creek.

Closer inspection, if all goes well, will disclose a building put together of high-quality materials with jewellike precision. The glass in this glass box won't simply be transparent -- it also will be translucent, in varying degrees, and thoroughly opaque where appropriate. Wood will be encased in glass laminates. The entire entry wall will be made up of thick panels of laminated glass that will be carved away for doors and rooms -- "like a sculpture," says architect Hansen. Subtle night-lighting will give a glow to the wooden undersides of the balconies.

And so on. The intention clearly is to make each detail as telling as the next, contributing to a clearheaded, yet astonishing, whole. Such ambitions are the sort that make you look forward with high hopes to the completed product. (That'll be sometime in 2006, Eliasson says.)

To complement this sure-handed architectural integration of inside with outside, landscape architect Johan Paju of the Swedish firm NOD conceived a five-part setting for the building, each part inspired by an aspect of Sweden's landscape -- the winter terrace, the barren rocky garden, the meadow, the forest pond and the beech forest.

Such metaphors, of course, can easily become cliches, and verbal description alone suggests that Paju could be trying to do too much in too little space. But what he seems to have in mind are rather low-key groupings of plants, subtly differentiated. His setting could turn out to be perfectly charming.

Security installations will have a lot to do with the final effect, as well. If they are too obvious or too intrusive, they could spoil Sweden's admirable intentions to create a cultural open house on the Potomac. That nation is to be congratulated, at the very least, for putting its best architectural foot forward -- Wingardh and Hansen were selected in a design competition among Sweden's foremost architects.

As the ambassador, the architects and others spoke at yesterday's unveiling, it was impossible not to ponder the grim irony in the course of embassy design during the last half-century. After World War II, it was the new U.S. embassies that set the standards for modernity, optimism and openness. Today, however, our country is reduced to building ambassadorial fortresses overseas.

Perhaps Americans can take some small pride, then, in fine designs such as this one for Sweden. After all, our old lessons about democracy and openness did take well.

"Like a wicker lamp": A model of how the proposed House of Sweden would look at night.A rendering of the proposed House of Sweden, which would face the Potomac in Georgetown near Rock Creek.