It is a most unusual and prepossessing sight a bell tower rising treetop high amidst a cluster of gabled roofs, all appearing, except for the newness of the brick walls, as if they had been there for years. And looking, too, a bit like an ancient monastery in Italy, or a little village in Scandinavia, or a parsonage in the English countryside.

But the buildings are new and are in Washington, and despite their seemingly generic parentage (or perhaps because of it), they do seem quite at home on their narrow lot in Northwest. The complex makes up the St. Patrick's Episcopal Church and Day School, on Whitehaven Parkway close by the Mount Vernon College campus.

Like many things that look easy, this wasn't.The Washington architectural firm of Hartman-Cox, which did the design, first had to convince the congregation that renovating another, older building in the neighborhood would not satisfy its needs. The church then had to purchase land from the college to accommodate new construction and maintain athletic fields. The architects, meanwhile, had to pick and choose among items on an imposing list of needs and wants compiled by the clients.

"Even the Washington Cathedral couldn't have handled everything they wanted to do," said George Hartman, the partner in charge of the design. The complexity and length of the wish list did, however, lead naturally to the decision to form the project in the image of a cloister, with outbuildings huddling near the tower, as if for protection.

This plan, with its central courtyard, solved the problems of access to the many purposes of school and church. More importantly, it was the takeoff point for an amazingly apt and persuasive image. The new place tells even the casual passerby that there is a church here, and that it is the actual and spiritual center of a host of different activities.

Not coincidentally, this basic idea enabled the architects to resolve with grace a potentially abrasive collision of styles and attitudes, for they had somehow to deal with an existing school on the western portion of the site, a bulky, antihistorical functionalist box completed about a decade ago. With intentional irony, but without rudeness, the Hartman-Cox team made sure that the strong, varied and insistently vertical masses of the new complex gently enfold the existing school -- so much so that in a few years, when the new brick has weathered some, the older building likely will seem an economical addition to the "cloister."

The verticality of the new complex, with all gables set at an identical 45-degree pitch, also derived from the architects' concern with historical image. "We wanted a building shape that definitively said 'church,' and my mind kept going back to that little Renwick chapel in Georgetown," Hartman explained, referring to the tiny Gothic piece in Oak Hill Cemetery designed by James Renwick in 1850.

It is interesting how so simple a mental picture can bring forth so rich a design. Of course, there were all those practical needs to be met -- the complex includes administrative offices, additional spaces for the elementary school that do double duty for youngsters at the church on Sundays, a library, a center for elderly parishioners and, not least, the church itself. Here was an opportunity to create a number of affecting spaces, and the architects took advantage of their chance.

The church interior, for instance, is a commodious meeting room that manages to be at once intimate and spacious, simple and complex. The intimacy is partly due to a floor plan in which the chancel projects slightly into the nave, so that churchgoers face the preacher from three sides, and partly to the warm wood floors and movable seats (selected instead of fixed pews). But the ceiling, supported by exposed, spiderlike trusses, soars up above; natural light comes through gables that cut into the space from east and west. The white-painted end walls, sliced into positive-negative spaces reflecting the pitch of the gables, are, themselves, dramatic events.

Another exemplary space is the parish hall, with high ceilings and walls saturated by natural light. Still another is the library, which, though unfinished, clearly can be made into a warm and contemplative place from which a reader will glance occasionally out windows opening into a bank of trees in back of the building. Even rooms for the preschool children -- normally the most utilitarian of boxes -- were scaled to the size of their primary users, and given the comforting appeal of pitched roofs.

Clean lines distinguish the project both inside and out, a quality complemented by the spare elegance of the ornamentation: the change from dark to light bricks at the cornices and around windows on the exterior, for example, or the exposed trusses above the nave. One can't quite pin it down, but lots of references come to mind -- Romanesque niches, Italian campaniles, Renwick's gable ends, Alvar Aalto's trusses. The whole enterprise bespeaks an effortless sort of eclecticism.

"You hate to waste opportunities for free decoration," Hartman commented about the truss system, "so you make the structural system as appealing as possible. It would cost more to cover it up, anyway."

This attitude, coupled with design skills of a high order (the principal Hartman-Cox assistants on the job were Lee Becker and Peter Grina), explains how St. Patrick's manages to evoke history and tradition while avoiding lighthearted mimicry or heavy-handed reproduction -- two insidious temptations of postmodernism.

It is of course ironic that the physical coming together of church and school, formerly in separate locations, was the occasion for a well-publicized rift between the two (the school's principal recently was fired by the rector). Hartman, for one, wasn't so surprised. "I told them the old story about the couple who decides to save a marriage by building a new house," he recalled. "Sure, the marriage stays together, but when the house is finished, bam! -- then comes the divorce."

But short-term squabbles don't tarnish the long-term architectural significance of the new St. Patrick's. Hartman-Cox's innovative record in church architecture goes back a few years -- the Mount Vernon College chapel, completed in 1969, was the first of the firm's successful experiments in bathing religious interiors with natural light; Immanuel Presbyterian Church in McLean, five years old, duplicated this feat in a building notable for the clean-cut traditionalism of its form. St. Patrick's, our exceptional new symbol of spiritual community, is no small addition to the list.