Lakhasly

Contrasting Orientation
Just as two structural grids may have contrasting
geometries, they also might have differing orientations
to address unique features of a site, accommodate an
existing pattern of movement, or express contrasting
forms or functions within a single composition. And as
in the case of contrasting geometries, there are three
ways in which to resolve how the two grids that differ in
orientation resolve into a single structure.
• The two gridscan be keptseparate and be linked by a
third structural system.
• The two gridscan overlap with either one dominating
the other, or the two combining to form a third
geometry.
• One of the two gridscan incorporate the other into its
field.
The transitional or interstitial space formed by the
intersection of two geometries having contrasting
orientations can, if large or unique enough, begin to attain
an importance or significance of its own.
In the latter two cases, the resulting irregular or
nonuniform layout of vertical supports and varying span
lengths make it difficult to use repetitive or modular
structural members. See the following page for transitional
patterns to mediate between grids having differing
orientations.
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IRREGULAR GRIDS
The transitional link between two geometric
orientations may reflect either one of the orientations
or neither of them. If the linking space conforms to
one of the orientations, the contrasting orientation
will tend to be emphasized.
• Contrasting orientationscan lead to the linking
space having unique spanning conditions.
When two grids of contrasting orientation overlap,
one will tend to dominate the other. The ascendency
of one grid can be further emphasized by a change
in verticalscale. Strong structural and architectural
emphasis is placed on the exceptional spaces where
one can experience both geometries.
Another way of treating differing orientations is to
unify both parts by gathering them under a third
dominant structural form. Like the examples above,
emphasis occurs at the exceptional condition of two
different structural systems are juxtaposed.
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IRREGULAR GRIDS
Plan and section: Palmach Museum of History, Tel Aviv, Israel, 1992–1999, Zvi Hecker and Rafi Segal
STRUCTURAL PATTERNS / 67
IRREGULAR GRIDS
Plan and section: Valley Center House, San Diego County,
California, 1999, Daly Genik Architects
Plan and section:Lois & Richard Rosenthal Center for Contemporary Art,
Cincinnati, Ohio, 2001–2003, Zaha Hadid Architects
The examples on this and the previous page illustrate several ways in which
contrasting orientations can be accommodated within a single composition.
The Palmach Museum of Historyconsists of three parts, two of which are
skewed to preserve an existing cluster of trees and rocks and define an
irregularlyshaped courtyard. The structure of the Lois & Richard Rosenthal
Center for Contemporary Art is based on a regular rectilinear grid but the
columns have the shape of parallelograms to reflect the skewed geometry of
the full-height, skylit atrium space housing the vertical system of stairways.
The Valley Center House usesthe main living room as a transitionalstructure
that rises above to visually link the contrasting orientations of two wings.
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IRREGULAR GRIDS
Accommodating Irregular Spaces
Design ideas are often generated not from the pattern of
structural supports and spanning elements but rather from
the desired ordering of program spaces and the formal
qualities of the resulting composition. In a typical building
program, there are usually requirements for various kinds
of spaces. There may be requirements for spaces that are
singular and unique in their function or significance to the
building organization; others may be flexible in use and can
be freely manipulated.
Discrete irregularspaces may be framed bythe structure
to conform with and reinforce the program requirements of
the spatial volume.
This usually involves working back and forth between
a structural concept and the program requirements for
the space, searching for an appropriate fit between the
structural strategy and the vision for the formal, aesthetic
and performance qualities of the resulting spatial
environment.
A discrete irregular space may also be developed as an
independent structure with a separate structural system
and geometry superimposed over the building as a
whole. Although appropriate to accommodate the spatial
requirements of such spaces as theaters, concert halls, and
large galleries, this strategy typically requires long-span
spanning systems. For a discussion of long-span structures,
see Chapter 6.
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IRREGULAR GRIDS
Accommodating Irregular Shapes
See plan and section of Centre Le Corbusier, pg. 16.
Plan diagrams: Mill Owners’ Association Building, Ahmedabad, India, 1952–1954,Le Corbusier.
70 / BUILDING STRUCTURES ILLUSTRATED
IRREGULAR GRIDS
Accommodating Irregular Shapes
It is advisable to try to recognize the inherent geometry
embedded in irregular plan shapes when attempting to
develop a strategy for its structural system. Even the
most irregular of plan shapes can often be dissected into
parts which can be seen to be transformations of regular
geometric shapes.
The manner in which an irregular shape or form might be
constructed will often suggest logical options for a framing
strategy. This may be as simple as using the center of
an arc for a radial framing system or framing parallel or
perpendicular to a significant wall or plane within an
irregular geometry. Curves, especially, possess a number of
properties for establishing the basis for a framing strategy.
One might use the radius orcenter of an arc, a point that is
tangent to the arc, or in the case of double curvatures, the
inflection point where a change in curvature occurs. The
approach one takes will depend on the design intent and
how the structural strategy might reinforce the concept.
Although structural framing systems are usually developed
in plan, consideration should also be given to the effect
of the structure on the vertical aspects of a building—its
elevations and the scale of its interior spaces. If column
locations will be expressed in the facade, for example,
the visible effect of a regular column spacing on a curving
exterior wall plane should be considered.
Part of the challeng