One of my favorite aphorisms is that if you put two architects together in a room, you'll get three opinions.

The credibility of this observation is frequently reinforced when architectural design review bodies struggle to form opinions about additions to American cityscapes.

In the last 20 years, increasing numbers of jurisdictions -- towns, cities, counties, even homeowners associations -- have established design review bodies. Their purpose is not to slow or control growth. Rather, the goal in most cases is to elevate overall standards of design and to ensure esthetic quality.

With members typically appointed by mayors, planning commissioners or other governmental executives, design review committees rarely have legal authority. Instead, most serve in an advisory capacity, conveying recommendations to project sponsors and their architects, and to governmental entities making final decisions.

Yet design review proceedings and the individuals responsible for conducting them often have considerable influence, if not the final word, on the visual content and quality of what gets built within their purview.

And sometimes design review panels play an enforcement role when they check design proposals for consistency with established architectural guidelines. This differs, however, from the building permit review process, which verifies that a completed design meets building code and zoning standards, not esthetic standards.

Perhaps the most significant impact of design review agencies is on developers and architects. Simply put, architectural review makes everyone aim higher and try harder, since adverse judgments about design quality can cause delays, cost money and ultimately affect the "image" of both sponsor and architect.

In cities like Washington and Baltimore, where design review bodies have long been in operation, developers of major projects subject to design review have tended to select architects -- often from out of town -- with national or international reputations. Hiring a "name" architect is presumed to increase the chances for success.

Clients feel that designs by notable architects will be better, though perhaps costlier, and will be received favorably by design review committees. They also may believe that higher design aspirations will be more marketable and profitable.

Sometimes developers favor architects already acquainted with the officials and details involved in the review process. Designers well known to review committee members and staff may promise smoother movement through the gauntlet of meetings and negotiations. And there's always the hope that such architects know just what reviewers are looking for.

Of course, in opting for famous architects, or those experienced with the process, clients and the public still may not get the best possible design. Other talented architects, less famous and as yet untested by the design review process, may be overlooked.

Whatever the circumstances, the existence of an architectural design review process creates a kind of automatic filter. It can't guarantee landmark architecture, but it does encourage more than just "bottom-line" thinking. It won't produce perfect buildings, but it is likely to eliminate the worst and frequently the mediocre.

What about the composition and authority of review panels? Should they be independent, statutory bodies with absolute veto power over projects that don't pass muster? Should they review all projects, or just selected ones, within their jurisdiction? How interventionist should they be, given the thin line between "reviewing" and "redoing" an architect's design?

There always will be debate about the degree of authority that review bodies should have, especially since most of their deliberations lie in the realm of esthetic assessment, personal taste and shifting opinion.

Because design review committee recommendations can be both persuasive and statutorially required, maintaining the advisory status of design review bodies seems sensible. Occasionally leeway may be needed to offset prevailing, but questionable, esthetic moods. Indeed, local government might disregard the findings of advisory design review proceedings, responding instead to social, economic and political pressures believed to be of greater interest to the public.

Or the public might disagree with the transient opinions of review committees. Recall the Roosevelt Memorial competition 25 years ago. The choice of the jury of design experts -- giant slabs of stone towering above the Potomac shoreline -- was resoundingly rejected by Washingtonians.

Some think that advisory design review panel members should be professionals with expertise in the design arts -- architecture, landscape architecture, city planning, sculpture, painting, architectural history and criticism.

Such groups could render opinions reflecting each member's special knowledge and experience as well as, unavoidably, prejudices.

Naturally, a panel of this type, likely to be esthetically sophisticated and demanding, could impose an excess of personal ideas on project designs, no doubt to the chagrin of the project architect.

Others insist that the ideal design review committee should include members, perhaps even a majority, who are not design professionals. Such members presumably would be more representative of citizen points of view.

But nonprofessionals likewise can bring to the review process strong and conflicting opinions about architecture, no matter how ill-informed, fashion-driven or superficially founded.

Given the choice, would architects prefer to debate the merits of their proposals with a panel of architects or with a panel of would-be architects? As always, opinions differ.

If a design review committee is purely advisory, then it should focus primarily on architectural merit. Consequently there seems little doubt that some committee memers should be recognized design professionals, since other steps in the project review and approval process offer the general public and special interest groups opportunities to formulate and convey their judgments.

An ideal committee might include people from both near and far with diverse interests and points of view. Serving staggered terms of appointment to maintain continuity, they should understand theories of design and complexities of development.

They must know the physical and cultural territory in which they operate. And while being fair yet rigorous in their evaluation, they must willingly take positions and make specific suggestions.

More, not less, design review is needed. Instead of requiring architectural review only in special districts, along special streets, or for special projects, communities should insist on some level of design review for virtually all buildings.

This might slow things down a bit and require many more review committees, but it undoubtedly would raise the level of architectural and urban design quality.

Every building, no matter where it is or how big it is, whether private or public, participates in making collective city and suburban environments.

Thus, all developers have some obligation to make buildings as good as they reasonably can be. Helping to fulfill this obligation is ultimately the mission of design review committees. And even a committee with too many opinions may be better than none at all.

NEXT: Design review in action. Roger K. Lewis is a practicing architect and a professor of architecture at the University of Maryland.