Judging from contemporary architecture featured in the media, you might think that the 90-degree angle is passé. Among current architectural fads, non-orthogonal design -- shaping architectural mass, space and surface without using right angles -- is increasingly evident.
Architects seem to be designing ever more projects incorporating not only acutely angular geometry, but also complexly curved or faceted walls and roofs.
We see this in many dynamic recent projects: the new, glass-sheathed Seattle Public Library designed by Rem Koolhaas; the starkly symbolic, zig-zagging Jewish Museum in Berlin designed by Daniel Libeskind; any project, built or unbuilt, designed by Zaha Hadid; and, of course, the metal-clad, exploding and colliding forms crafted by Frank Gehry.
Non-orthogonal geometries can be aesthetically and functionally appropriate. But their use in many projects seems arbitrary and capricious. Too frequently, such geometries are little more than willful gestures having little to do with project circumstances or rational construction.
Like many once-original ideas, non-orthogonal design has gone from being special to being trendy.
Strong architectural concepts reflect project conditions as well as the creativity of the designer. But an innovative idea, once executed, can catch the eye of other designers and appeal to them for purely visual reasons. The catchy, aesthetically stimulating idea then begins appearing elsewhere, and before long it has become little more than a faddish, overused motif.
Departing from right angles is not intrinsically wrong. The history of architecture is replete with wonderful compositions based on triangles, hexagons, octagons and irregular polygons, not to mention circles, ellipses, parabolas and other curves.
Use of these geometries is typically motivated by four considerations.
• Structural system stability. Because the triangle is the only inherently stable polygon, architects and engineers have long exploited triangular geometry. Triangles occur primarily in supporting components made by assembling linear elements of wood or steel: walls, vaults and domes.
• Functional plan configuration. Theaters, auditoriums, churches and building lobbies commonly have non-orthogonal geometries to achieve desired acoustical, visual and even psychological properties.
