In an architectural school studio late one night, a fellow design student, borrowing from Shakespeare's King Richard III, cried out plaintively, "An idea, an idea, my kingdom for an idea!"

With little time remaining to complete his studio project, he still was searching desperately for some elusive insight that would allow him to formulate an architectural statement. Like generations of architectural students preceding and following him, he was struggling with the often mysterious act of design.

How do architects design? The search often begins with givens that define a project's mission and constraints.

* The program (a description of needs, activities and space requirements), plus a project budget which outlines the economic resources available.

* The site, which presents geometric, topographic, geological, climatic, scenic, and other natural features along with man-made characteristics -- existing buildings and neighborhoods, streets, utilities and other constructed forms.

* Regulations applicable to the project and site, contained primarily in zoning ordinances that restrict building use and size, and building codes that prescribe safety criteria for design.

Even if you had a computer capable of absorbing the above data, it, like the architectural designer, still would face the potentially infinite number of design solutions that could prove functionally satisfactory. To make architecture, therefore, analyzing all the givens and their priorities is necessary, but never sufficient. The design act needs something more.

Architectural ideas are needed that go beyond pragmatic problem solving. But where do these ideas come from, and how do architects manipulate them? The list is long, but most relate to one or more of the following sources or rationales.

* The technology of construction and its formal expression can produce an architecture where methods of assembly, materials, structure, mechanical systems and other building components constitute the primary visual language.

* Abstract geometrical form-making employs familiar figures or solids (squares, cubes, circles, cylinders, triangles, pyramids, hexagons). They can be used literally, as pure shapes, or deformed, eroded, and combined to configure buildings.

* Functional diagramming inspires some architects to design buildings whose exterior wrapping reflects the uses, spaces, and circulation elements within. Corridors, stair and utility cores, activity zones, specially shaped spaces, and even bathrooms may emerge and manifest themselves in or on the facade.

* The architect may decide to make a building "look" like something else via metaphoric reference. The something else can be almost anything (a machine, an animal, a plant, a molecule, a piece of swiss cheese) and can be chosen for any reason, as long as the client is willing and the design is lawful.

* By historical reference, the architect can adopt as a model a place or existing building which seems appropriate for the current project. Appropriateness may be predicated on functional analogy (same use type), but some architects may be more interested in purely visual or cultural transplants. Revivalists may be literal in replicating previous ideas, while others might borrow only parts of the precedent ideas and motifs. Some interpret and transform substantially the historical precedent and its design vocabulary so that the new project alludes to, but does not copy, its forerunner.

* Contextual reference, the good neighbor approach, entails borrowing or extending design ideas and motifs from adjoining buildings, neighborhoods or regions. Projects so designed fit in with their surroundings by sharing attributes such as color, materials, height, massing, decoration, door and window type, and overall style, perhaps appearing to have been there all along.

Common to all of these idea sources is the inescapable notion of preconception which everyone brings to the design act. Our cultural traditions and experiences -- what we have grown up with, seen around us, and learned -- color our beliefs and expectations. Architects in particular are expected to have large, refined repertoires of pre-conceived notions and images enabling them to design architecture that is rich in ideas and well composed.

In fact, compositional skill is indispensable to implementing the architect's intellectual and emotional conceptions, for good ideas can be badly composed just as bad ideas can be beautifully composed. Compositional strategies include using grid patterns, axiality, symmetry and asymmetry, rhythm, repetition, and proportioning systems. Juxtaposition, overlapping, layering,interpenetration, and modulation are among the words architects utter when discussing their tactics for composing spaces, volumes, surfaces, and sites.

Thus the architect must somehow take all the givens, plus his or her pre-conceived ideas, and, through graphic experimentation, try to compose a new idea. Because the number of variables is so great, the conflicting criteria so many, and the compositional possibilities so limitless, design always is a challenging but fascinating undertaking. It is both a "Cook's Tour" and a "Lewis and Clark Expedition." You know generally where you want to go, yet you're never certain how you're going to get there or what it will be like until the trip is over.

By drawing hundreds and hundreds of sketches, the architect develops design ideas while exploring thousands of design variables, but only a few at a time in each sketch. Through overlays of tracing paper, successive sketches become transformations and refinements of previous ones.

Drawings show how a site could be occupied and landscaped, how a building could be massed volumetrically, and how the plan could be orchestrated using rooms, circulation spaces, courtyards, columns, and walls. The designer draws sections, elevations, and perspectives to show horizontal and vertical relationships, structure, interior spaces, wall surfaces, and exterior facades.

Scale models show the three-dimensional forms and architectural character being proposed. As the design evolves, drawings increase in size and specificity. The design idea may have appeared first in a series of very small, diagrammatic sketches. But it must culminate hundreds or thousands of hours later in many very detailed documents which are unambiguous about what's to be built and how it will look.

During this evolution, the architect doesn't work alone. The effort is collaborative. Many meetings with the client, who must understand and approve the work, influence the design. Jurisdictional authorities often are consulted for code reviews and occasionally for aesthetic evaluations..

Once basic architectural outlines are established, structural engineers begin designing foundations and structural members. Civil engineers tackle grading, utilities, roads and tunnels. Mechanical engineers design heating and air conditioning systems, while electrical engineers worry about electrical distribution and lighting, plus communication, security, and fire protection systems. These engineered systems must be anticipated and coordinated with the architect's design to make sure that they all fit together without conflict.

The history of a project's design is a history of trial and error, of testing and modifying, of analysis and intuition. It is at once science and art. It demands that aesthetic risks be taken and willful decisions be made reflecting the tastes and biases of architect and client. Above all, it takes time and dedication to do it well. And money helps, too.

Nevertheless, final results will be architecturally successful only if the client remains committed to design quality, and if builders care about craftsmanship when they carry out the design.

NEXT: Washington's architectural styles