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Along with plan and elevation, section is one of the essential representational techniques of architectural design; among architects and educators, debates about a project's section are common and often intense. Until now, however, there has been no framework to describe or evaluate it. Manual of Section fills this void.

Paul Lewis, Marc Tsurumaki, and David J. Lewis have developed seven categories of section, revealed in structures ranging from simple one-story buildings to complex structures featuring stacked forms, fantastical shapes, internal holes, inclines, sheared planes, nested forms, or combinations thereof. To illustrate these categories, the authors construct sixty-three intricately detailed cross-section perspective drawings of built projects—many of the most significant structures in international architecture from the last one hundred years—based on extensive archival research. Manual of Section also includes smart and accessible essays on the history and uses of section.
Princeton Architectural Press
208 / 210
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Princeton Architectural Press, New York


The Vertical Cut


Types and Performance of Section


Excerpts from a History of Section











18 4

LTL in Section


Sections by Height


Index of Architects


Drawing Credits




Image Credits


About the Authors

The Vertical Cut
This book presents the means for understanding the complex
and important role that section plays in architectural design and
practice. Discussion and debate of a particular building’s section
are common in the study and practice of architecture. Yet there
is no shared framework for the determination or evaluation of
section. What are the different types of section, and what do they
do? How does one produce those sections? Why would one choose
to use one configuration of section over another? This book explores
these questions and provides a conceptual, material, and instrumental framework for understanding section as a means to create
Our work has been motivated by the belief that the architectural
section is key to architectural innovation. Given the environmental
and material challenges that frame architectural practice in the
twenty-first century, the section provides a rich and underexplored
opportunity for inventively reimagining the intersection of structural,
thermal, and functional forces. Moreover, the section is the site
where space, form, and material intersect with human experience,
establishing most clearly the relationship of the body to the building
as well as the interplay between architecture and its context.
As practitioners and educators, we are invested equally in section as a type of representation and as a projective tool for spatial
and material invention. We offer with this book a clear heuristic
structure for a more robust discourse a; round the architectural
section, to establish a shared basis for dialogue toward explorative
and experimental architecture. Newly generated section perspectives of sixty-three significant built projects, organized into seven
distinct types, provide students, architects, and other readers with
a foundation for further cultivation of the section.
LTL Architects, Park Tower, 2004

We begin with the seemingly obvious question “What is a section?”
In reference to architectural drawing, the term section typically
describes a cut through the body of a building, perpendicular to
the horizon line. A section drawing is one that shows a vertical cut
transecting, typically along a primary axis, an object or building.
The section reveals simultaneously its interior and exterior profiles,
the interior space, and the material, membrane, or wall that separates interior from exterior, providing a view of the object that is
not usually seen. This representational technique takes various
forms and graphic conceits, each developed to illustrate different
forms of architectural knowledge, from building sections that use
solid fill or poche to emphasize the profile of the form, to construction details that depict materials through lines and graphic conventions. In an orthographic section the interior is also described
through interior elevations of the primary architectural surfaces,
while the combination of a section with a perspective describes
in depth the interior as a space, using the techniques of perspec6

tival projection.

Because the section begins with the visualization of that

Revealing Cuts

which will not be directly seen, it remains abstracted from the
dominant way of understanding architecture through photographs
and renderings. Sections provide a unique form of knowledge,
one that by necessity shifts the emphasis from image to performance, from surface to the intersection of structure and materiality
that comprises the tectonic logic of architecture. At the same
time, section demonstrates the exchange among multiple aspects
of embodied experience and architectural space, making explicit
the intersection of scale and proportion, sight and view, touch
and reach that is rendered visible in the vertical dimension (as
opposed to from top down). In a section, the interior elevations of

Ottavio Bertotti Scamozzi after Andrea Palladio, Teatro
Olimpico, 1796

walls and surfaces are revealed, combining—for examination and
exploration—structure and ornament, envelope and interior.
Plans and sections are similar representational conventions
and offer an important point of comparison. Both depict a relationship that is not directly perceivable by the human eye, between
a building’s mass and the space. Both describe cuts—the one
horizontal, the other vertical. The horizontal division of a plan cuts
primarily through walls, not floors. Sections, on the other hand,
are capable of showing cuts through both walls and floors and
organize space in alignment with the size and scale of the standing
human figure. Plans are typically argued to be the locus of design
agency, with sections understood as a means to manifest the
effects of the plan through structure and enclosure. In comparison to plan types, which are distinguished by their spatial consequences, section types are usually identified by the scale of their
cut: site sections, building sections, wall sections, detail sections.
Wall and detail sections foreground technical concerns, using
graphic conventions of line, hatch, and tone, and depict material
systems and tectonics. Site sections emphasize a built form’s
massing and its relationship with its environment and decrease
the role of internal space. But it is in the building section that a
number of crucial issues are at play, including the formal, social,
organizational, political, spatial, structural, thermal, and technical.

Thomas Ustick Walter, US Capitol Dome, 1859

The section is not limited to its status as a representational technique. Today sections are used expansively to illustrate, test, and
explore architectural designs. The section illuminates the interplay
between a building’s structure and the space framed between
foundation and roof. Gravitational loads of structure trace verti-

Le Corbusier, Unité d’Habitation, 1952

cally down through a building, with wind loads registering laterally
against the side of a building’s section. The material investment
and spatial invention necessary to creatively resist these loads is
best explored and depicted through the architectural section.
As questions of energy and ecology have become increasingly
important to architectural design, the section will take on a more
prominent role. Thermal forces work in section. Cold air is heavier
and settles, while hot air rises. The sun rises and falls against the

Affonso Eduardo Reidy, Museum for Modern Art, 1967

horizon. The vertical calibration of space is essential for inventing
and creating architecture to engage environmental performance.
Architects need to calibrate overhangs and apertures to produce


Thermal Sections

the optimal solar radiation; interiors should be configured to maximize convection-driven air movement; roof pitches need to be
set to ensure the efficiency of solar panels; wall thickness must
be dictated by insulation calculations; and so on. Often driven by
a desire to meet sustainable certification criteria, architects and
engineers use section drawings to illustrate adherence to conventions of thermal performance, with arrays of arrows illustrating thermodynamic forces. This emphasis on thermal efficiency
foregrounds the opportunities of the section, but paradoxically
constrains the spatial and experiential potential of the section by

Candilis Josic Woods, Shading Diagram, 1968

aligning sectional innovation to only functional obligations.
Yet, despite the importance of section as a drawing type and
as a key method for optimizing spatial qualities, structural design,
and thermal performance, there is a relative paucity of critical
writings or discourse on section. A well-established body of
writing exists on the history and impact of the plan, but there is
no single book on the history, development, and use of the section
within the practice of architecture. Only a few essays on section
have been published, with the two most often cited written
more than twenty-five years ago: Wolfgang Lotz’s “The Rendering
of the Interior in Architectural Drawings of the Renaissance”1
and Jacques Guillerme and Hélène Vérin’s “The Archaeology of
Section.”2 Interestingly, both essays have parallel motives beyond
cultivating and describing the architectural section itself.
This lack of direct attention may very well come from the
ambiguous position that section occupies. It is often understood
as a reductive drawing type, produced at the end of the design
process to depict structural and material conditions in service of
the construction contract, rather than as a means for the investigation of architectural form. While we are interested in the
representational conditions of section, we argue that thinking and
designing through section requires the building of a discourse
about section, recognizing it as a site for invention.
The initial challenge in creating meaningful and accessible discussions of the section is the absence of a language that would
provide a shared frame of reference. To address this void, we have
devised a category system based on seven distinct section types:
Extrusion, Stack, Shear, Shape, Hole, Incline, and Nest. The

Foster + Partners, Commerzbank Headquarters, 1997

vast majority of sectional relationships can be described by one
of these categories or several in combination. These types are
intentionally reductive in order to make recognition simple; they
are rarely found in pure form. Indeed, upon close inspection, no
project perfectly demonstrates only one type of section, as all
tend to have aspects of two or more. But where a dominant type
of section prevails, that designation is given.
Our purpose is not to present these types as a new kind of
Platonic ideal to be pursued in isolation. The fact that a building’s
section may exemplify one of these types does not automatically

Bucholz McEvoy Architects, Limerick County Council, 2003

denote a particular significance or meaning. Rather, respectful of
the potential of architecture, we provide these types as a heuristic


frame for building a discourse about section at the intersection

of material, cultural, and natural systems. Our objective is to learn

Section Perspectives

more about the ways in which section types or combinations of
types might be used and how this understanding could serve the
discipline of architecture. As we argue, each type of section lends
itself to distinct capacities, from the cultivation of a shared sense
of space to the facilitation of thermal performance, from the
establishment of spatial hierarchies to the enhancement of the
interplay of exterior and interior.
The following terms and definitions will be explained in the
subsequent essay in greater detail:

Charles de Wailly, Comédie-Française, 1770

Extrusion: the direct extrusion of a plan to a height sufficient for
the intended use
Stack: the layering of floors directly on top of one another—an
extruded section, repeated with or without variations
Shape: the deformation of one or more of the primary horizontal
surfaces of a building to sculpt space
Shear: the use of a rift or cut along either the horizontal or vertical
axis of a building to generate sectional difference
Hole: the deployment of any number or scale of penetrations
through a slab, exchanging lost floor area for benefits in section
Incline: the manipulation of the angle of an occupiable horizontal

Jacques-Germain Soufflot, Pantheon, drawing by
Alexandre-Théodore Brongniart, ca. 1796

plane, which tilts the plan into section
Nest: the creation of sectional consequences through an interplay
or overlap of legible volumes
Sixty-three one-point-perspective section drawings of built
projects form the central portion of this book. We selected these
projects because they represent a range of approaches to section,
forming a body of work useful for further study, development,
and inquiry. Certain projects illustrate one of the section types in
a clear and demonstrative way. Other projects exhibit complex and
creative approaches to section, often incorporating two or more

Henry Bessemer, saloon steamer, 1874

types in a wide range of new formations that transcend the limits
of a particular type in isolation.
All projects date from the turn of the twentieth century or later,
a time frame chosen because of its historical alignment with the
proliferation of standardized and industrialized methods of building. These methods typically have given rise to repetitive stacked
sections, placing a new imperative on the section as a site of
investigation and invention. We included only projects that have
been built, to ensure that there would be sufficient documentary
evidence to show the tectonic logic of the section and to verify
that the complexity of the section did not come at the expense of
Although many existing publications analyze and assess these
sixty-three projects, most do so by seeking to break each project

Louis-Auguste Boileau, system of interlocking arches,
drawn by Tiburce-Sylvain Royol, ca. 1886

into a series of discrete, easily digestible points. This reductive
approach suggests that the comprehension of a building’s complexity can be best achieved through categorizing concepts in isolation.
Our approach is the opposite. We aim through a single, detailed
drawing to demonstrate the range of intertwined issues that make
architecture compelling. The section perspective intentionally


combines the objective, measurable information of the section
with the subjective visual logic of the perspective. As such, the
drawings created for this book delineate facts and evidence while
enticing the viewer into a rich spatial experience. The drawings are
both abstract and immersive, analytical and illustrative. They build
upon a history of this representational technique that includes
such varied sources as the meticulous drawings of the École
des Beaux-Arts; the analytical, technical drawings of the industrial
era; Paul Rudolph’s line rendering of complex spectacles; and
McKim, Mead & White, Interborough Rapid Transit
Powerhouse, 1904

Atelier Bow-Wow’s hybrid mix of detailed construction drawings
with outlines of interior activity.
Representing each project through a single section perspective with a standardized view allows comparison among and
across projects. To create each drawing, we built a digital model
and established a section cut true to the orientation of the page,
not in oblique or perspective. We then set a single vanishing
point, adjusting the perspective lens to bring interior or exterior
surfaces into view, thus establishing a visual correspondence
between the cut plane and the vertical surfaces that compose
the projects. From each model, we exported a two-dimensional

Jacques Hermant, Société Générale, 1912

line drawing, which we adjusted and developed in a vector-based
line program. The completed drawings follow the conventions of
sectional drawings, where, for instance, the outside cut line that
separates the edge of a solid surface and the open air or space
beyond is marked by the thickest line, while lighter lines are used
to illustrate secondary material distinctions within a cut solid or to
describe the details of a surface viewed beyond the cutting plane.
These drawings differ from drawings of archaeological ruins,
where the deterioration of a structure reveals its section to the
observing eye. Since we cannot, of course, cut directly into built
works, our representations depend on interpreting other drawings

Paul Rudolph, Yale Art and Architecture Building, 1963

and images to create an accurate assessment of material conditions. These other drawings are themselves often approximations
of construction yet to happen, thus raising compelling questions
about historical accuracy and the construction of knowledge.
The work of this book is based on photographs, drawings, descriptions, and, where possible, original archival construction drawings
and /or digital files obtained directly from architects’ firms. The
drawings in this book are as precise as practicable, given available
representations and the impossibility of absolute precision that
is inherent to the section as a representational technique.
In addition to creating the sixty-three section perspectives, we
have selected historically significant or otherwise compelling section drawings from throughout the history of architecture. These
section images, which accompany the book’s essays, include
some unbuilt works in order to show the wide range of possibilities
for using section to illustrate and generate architectural form. A
chapter on the use of section as a generative tool for the work of
our office, LTL Architects, complements the sixty-three projects.

Atelier Bow-Wow, Bow-Wow House, 2005

This work illustrates additional explorations in combining section
and perspective, ones in which the section cut itself is put into
perspective, as well as speculative projects, in which section is the


generator for spatial and programmatic interplay.

Types and Performance
of Section
Extrusion, Stack, Shear, Shape, Hole, Incline, and Nest are

Extrusion Sections

separate and primary methods for operating in section. For the
sake of clarity, they are presented as distinct modes, but they
rarely operate in isolation. Buildings exhibiting the most complex
and intricate sections contain all manner of combinations. Nevertheless, the distinctions among the types provide a means to
articulate how an architectural section is produced and to understand its effects.

Ralph Rapson and Eero Saarinen, Demountable Space, 1942

The extrusion of a plan up to a height sufficient for the intended
activity is the most basic form of section. An extruded section
has little to no variation in the vertical axis. The vast majority of
buildings are based on this efficiency, including most one-story
office buildings, retail structures, big-box stores, factories, singlestory houses, and apartments. Usually built with flat concrete
slabs and rectilinear steel or wood frames, it produces the maximum usable square footage in relation to overall building volume.
Elaboration of more complex sectional qualities is anathema to

Ludwig Mies van der Rohe, Farnsworth House, 1951

this model of efficiency. More complicated sections have the consequence of reducing valuable square footage of real estate. In
extruded sections space is activated largely through plan and, to
a lesser degree, elevation. It is a banal base against which other
developments or types of section can be understood. This type of
section usually lacks distinctive qualities, although in cases where

Ludwig Mies van der Rohe, Chicago Convention Center, 1954

an extrusion fails to meet typical models of efficiency, it can produce intriguing effects, including claustrophobia or agoraphobia.
One can find examples of extrusions that are extremely low—for
example, the half-floor sections found in Spike Jonze’s film Being
John Malkovich—or extremely high, such as the vast interior space
of the Palace of Labor by Pier Luigi Nervi. In extruded sections,
the ceiling is often the site of design investment, for reasons of
structural articulation and the sheer extent of this surface.

Arne Jacobsen, National Bank of Denmark, 1978

Given that a straight extrusion is rarely remarkable, only a
few of the buildings in this book are based solely on extrusion.
A key condition of the extruded section is the role of the structure
that separates the floor from the ceiling or roof. The Glass House
by Philip Johnson places extraordinary emphasis on steel columns
that rise from regular locations on the plan. The glass walls in
effect turn the elevation into the section. The one anomaly of the
system is the combined bathing area and fireplace, joined together

Renzo Piano, the Menil Collection museum, 1986

to hide all the house’s plumbing and heating systems behind the
extruded figure of a brick cylinder, to preserve the clarity of the
sectional diagram. While Johnson places the columns within the
window wall external to the inhabitable space, Junya Ishigami
does nearly the opposite with the Kanagawa Institute of Technology
Workshop, dispersing or aggregating its columns to fill and frame
the space as a field for different and adjustable uses. For Ishigami,


Stack Sections

the extruded section heightens the distinction between the solid
concrete base encasing and cantilevering the multiple thin columns and the highly articulated steel ceiling, whose pattern turns
the structural diagram into ornament. While the two previous
examples work within conventional extruded ceiling heights, in the
Palace of Labor in Turin, Pier Luigi Nervi used the massive scale
of mushroomlike columns to aggrandize an exhibition hall. Sixteen
repetitive structural units define a 70-ft-high space. Although
justified by pragmatics of construction speed and efficiency,
the excessively tall space, animated by a grid of robust, tapered

Le Corbusier, Maison Dom-ino, 1914

columns, transforms an extruded section into spectacle.
Stack is the placing of two or more floors or spaces on top of
one another, with little connection among the individual stories.
Stacking increases the real estate value of a property by expanding the square footage and usable capacity of a building without
increasing its footprint. Financial gain is a basic motivation for
the use of stacked section in architecture. Repetitive stacks are
similar to extruded sections and can be deployed ad nauseam until
limited by code, cost, or structural stability. Alternatively, stack
can be created by placing very different floor types and shapes on
top of one another. By itself, stacking does not produce interior
effects. In office buildings or apartments, for example, each floor
can be added with little or no consequence to the previous floors,
beyond the impact on the quantity of vertical services required.
It is precisely the ease of this accumulation that thwarts any
sectional variations; its efficiency is based on the homogeneity
of the section. It costs less to build the same floor than to introduce variations; all the expertise of Taylorism remains intact, from

Antonin Raymond and Ladislav Rado, prototype for a
department store, 1948

drawings to formwork to sequence of construction.
In buildings with single programs the extrusion rarely varies
from floor to floor. Yet architects have exploited differences in the
height of that extrusion on different stacked floors to allow for
programmatic variation. A well-known example is Starrett &
Van Vleck’s Downtown Athletic Club, which comprises thirty-five
levels with nineteen unique floor-to-floor heights, ranging from
6 ft (1.8 m) for a “bedroom utility” to a 23-ft-6-in (7.2 m) “gymnasium.” Rem Koolhaas’s influential analysis of the building in
Delirious New York explicates the “culture of congestion” enacted
within the building, where each of its “superimposed platforms”
sponsors distinct uses, spaces, and experiences. The power of
the building is derived from the sectional autonomy of each floor;

OMA, Center for Art and Media Technology, 1989

the stacked section creates a form of seduction. “Each of the
Club’s floors is a separate installment of an infinitely unpredictable
intrigue that extols the complete surrender to the definitive instability of life in the metropolis.”3 Critical to this reading is the fact
that the Downtown Athletic Club’s section cannot be experienced
optically or synchronically. Rather, it is through the diachronic
mechanism of the elevator that the narrative of programmatic and

Simon Ungers, T-House, 1992


sectional disjunction unfolds. The Downtown Athletic Club is a
peculiar project in that the fit between program and section is so
precisely aligned, as gymnasiums, swimming pools, and handball

and squash courts all require specific ceiling heights, and the
relatively small footprint of the building allows each of these
programs to inhabit its own floor.4
Whereas the Downtown Athletic Club conceals the variations
of its section behind a muted facade, floor-to-floor variations
in a stacked section have been used as the very image of other
buildings: for example, MVRDV’s Expo 2000 Netherlands Pavilion.
Deploying the same logic used to create multilayered cakes,
MVRDV juxtaposes completely different architectural spaces,
from columnar halls filled with trees to a cast-concrete grotto,
all topped by a trussed roof marked by wind turbines. Each floor
is unique and varies substantially, demonstrating through the
section an accumulation of different ways architecture engages
environmental systems. Connection among the different stacked
floors is made only through staircases and a bank of elevators
clipped onto the exterior of the structure, reinforcing the independence of each zone.

SANAA, Christian Dior Omotesando, 2003

Since stack is based on multiples, an alternate approach
takes advantage of repetition, varying only floor heights to create
difference. By adjusting the floor height while keeping the profile
of each floor the same, SANAA created a distinctive building
for the Dior flagship store, its seductiveness a product of the
elegance of the architectural operation. In contrast, the individual
galleries of Peter Zumthor’s Kunsthaus Bregenz are treated as
separate volumes, staggered and stacked with the same space
between each floor. Services and lighting occupy the stacked

Will Alsop, Ontario College of Art and Design, 2004

spaces between the galleries, with the entire ensemble nested
within a double-skin glass shell.
Ludwig Mies van der Rohe’s work at S. R. Crown Hall at IIT
disguises the stacked section behind a singular architectural form.
In truth, the monumental exposed structural beams that mark the
profile of the building only support the ceiling of the main floor. A
more utilitarian lower floor sits below, half-sunken into the ground
and supported by load-bearing walls. The exterior curtain wall,
marked by continuous vertical steel members, cloaks the section's
stacking, reinforcing the impression of a singular spatial volume.
The stacked section limits the thermodynamic movement of
air and water. In order for these systems to serve a building, they
must be pumped, pushed, and ducted vertically beyond a single
floor. Louis I. Kahn’s design for the Salk Institute exploits this
isolating condition to full effect. To accommodate the extensive

Christian Kerez, school in Leutschenbach, 2009

mechanical services needed for research labs and ensure that
those spaces would be column-free, Kahn layered on top of each
laboratory a full floor dedicated to systems threaded through
an open Vierendeel truss system. Three successive pairings of lab
and service zone make up the stacked section.
Shaping is the sculpting of space through the deformation of a
continuous horizontal surface or surfaces. This adds a particular
volume or form to the section and can occur in a floor or a ceiling
or both. Shapes can exhibit an extremely wide range of topologies.5 The ceiling is a more common location for this modulation

GLUCK+, Tower House, 2012


Shape Sections

than the floor, as variations in a ceiling do not affect a plan’s
efficacy. Load-bearing masonry cathedrals, covered stadiums,
igloos, and tents all have shaped sections. Buildings with shaped
sections frequently exhibit a close fit between their structure
and their section, often incorporating vaults, shells, domes, and
tensile membranes, with the shaping of the roof aligning with
gravitational load paths and structural spans. Much of the work

Pantheon, AD 128

of Félix Candela demonstrates quite clearly the intersection
of structural forces and shape in section, as in his design for
Los Manantiales Restaurant, consisting of a thin-shell concrete
roof cast into hyperbolic-paraboloid forms. The project is in
essence a physical manifestation of a structural diagram. Marcel
Breuer’s Hunter College Library is another example of a structural
form, in this case assembling a flowering column module into
a repetitive shaped section. Using more conventional framing,
Rudolph M. Schindler’s Bennati Cabin is constructed from
two-by studs organized into triangles, forming an early example

Andrea Palladio, Villa Foscari, 1560

of an A-frame house. The shape is structurally efficient, permitting a large living floor below a narrower sleeping loft, with
the triangular shape fulfilling local ordinance’s request for alpine
exterior aesthetics.
The dominance of flat-slab construction in the past century
has decreased the frequency of this type of section, as the separation of structure from enclosure, exemplified by Le Corbusier’s

Eladio Dieste, Church of Christ the Worker, 1952

Maison Dom-ino housing prototype, shifted the articulation of
space from section to plan. As Colin Rowe wryly notes about
Le Corbusier’s Villa Stein in “The Mathematics of the Ideal Villa,”
“Free plan is exchanged for free section.”6 Shaped section can
be found in buildings where an intensification of social space
and gathering is needed, including most buildings of collective

Eero Saarinen, Dulles Airport, 1962

worship. In churches and synagogues the ceiling can be used to
establish a focal point within a unified volume.
The Pantheon and Le Corbusier’s Notre Dame du Haut are both
sacred buildings with a shaped section, one concave, the other
convex. Both use the section to calibrate the play of natural light in
the space, and in both the section of the ceiling is aligned with
the structure to varying degrees. In a more secular context, Alvar
Aalto deployed a complex, sculpted ceiling to reinforce the legibil-

Hans Scharoun, Berlin Philharmonic Concert Hall, 1963

ity of different areas within the single open space of his library in
Seinäjoki, Finland, as well as to control daylight in the stacks.
In addition, Aalto stepped the floor, setting a reading room a halfstory down in the middle of the space to provide a sense of privacy
while still preserving visibility from the circulation desk above.
A modulated ceiling is frequently limited to a single-story building or to a building’s top floor, as the ceiling’s other side can be
hard to occupy without the introduction of poche, dropped ceilings,
or soffits. As such, a desire to manipulate a structure’s exterior

Kenzo Tange, Yoyogi National Gymnasium, 1964

to protect the interior space from the forces of nature can be a
catalyst for using this section type and often informs the shape
of the roof. This use of shape is clearly in evidence in Jørn Utzon’s
double-layered roof system for the Bagsværd Church, where a
complex, curvilinear interior ceiling is covered by a simplified rec-


tilinear shed. The section reveals the potential for a loose fit

between an exterior shape responding to the obligation of weather
enclosure and an interior ceiling that modulates light, sound, and
space for sacred purposes. Steven Holl’s project Cité de l’Océan
et du Surf presents a very different reason for a shaped roof. Here
the top of the building is an occupiable outdoor surface, shaped
to reflect the waves associated with surfing.

Johannes Hendrik van den Broek, Delft Auditorium, 1966

When a shaped section occurs in the floor, causing a disruption to the horizontal plan, it can cluster or choreograph collective programs, particularly those based on stasis. Theaters, auditoriums, and churches frequently use a shaped section in the floor.
It is also common for these building types to have adjustments
to their ceiling, often for acoustic reasons. While usually described

Louis I. Kahn, Kimbell Art Museum, 1972

exclusively with regard to its sloped floor, Claude Parent and
Paul Virilio’s Church of Sainte-Bernadette du Banlay equally displays section deformed by shape, with the roof and floor sculpted
and aligned to reinforce the spatial reading of the volume set on
an incline. Similarly, the design of SANAA’s Rolex Learning Center

OMA, Agadir Convention Center, 1990

aligns the shaping of the floor slab and the ceiling slab, but not
within a rectilinear envelope. Instead, the space between the
underside and the ground is visible and activated. As a hybrid project, the center can be characterized as an unusual combination
of an extruded section and a shaped section activated by holes.
Similarly, Toyo Ito’s Taichung Metropolitan Opera House uses
shape in combination with other types of section. However, it is
the sculpted concrete forms that dominate, set in contrast to the

Frank Gehry, Experience Music Project, 2000

repetitively stacked floor plates and active in the section, providing the key spaces throughout the project.
It’s instructive to note, however, the distinction between the
sectional transformations of shaped floors and those of complex
topography. In large-scale projects such as the Yokohama Ferry
Terminal by Foreign Office Architects or the Olympic Sculpture
Park by Weiss / Manfredi, the sectional profile tends toward landscape, with the topography of the landform not oriented necessarily toward the creation of interior architectural space. As these
projects expand in size and /or merge into the topographic conditions of the site, their sections are experienced and understood
less as shaped surfaces and more as extensions or transformations
of landscapes.

Weiss / Manfredi, Seattle Art Museum: Olympic Sculpture
Park, 2007

Shear involves a rift or cut parallel to either the horizontal or vertical axis of section. The subdesignations of vertical and horizontal shear are necessary, since each creates completely different
sectional operations and effects.
Vertical shear, where floor plates are cut and levels adjusted

Ryue Nishizawa, Teshima Art Museum, 2010

vertically, means that discontinuity in plan is coupled with new
forms of continuity in section. Vertical shear is particularly effective at inducing optical, thermal, or acoustic connections within
an extruded or stacked section without significantly compromising the tectonic efficiencies of repetition. This intriguing friction
can be used for different purposes. Split-level suburban houses
provide greater visual connection and flow between floors than
two-story houses. Typically, an entry combined with a kitchen and


Vertical Shear Sections

dining area is located halfway between a lower-level garage and a
more formal living room, with bedrooms above the entry. Rather
than simply serving as a connection between discrete floors, the
staircase in the split-level house can be argued to be synthetic
with the various floors, making the house an extension of the logic
of the stair.
In Herman Hertzberger’s design for the Apollo Schools, a
vertical shear allows for enhanced visual exchange among classrooms and hallways, encouraging theatrical social dynamics while

Frank Lloyd Wright, Unity Temple, 1906

simultaneously allowing the majority of the classroom spaces to be
tucked beyond diagonal sight lines. This creates what Hertzberger
calls “the right balance between view and seclusion.”7 More
extreme juxtapositions between plan and section can be intensified through a vertical shear. Diller Scofidio + Renfro uses vertical
shear in Brown University’s Granoff Center for the Creative Arts to
induce visual dialogue between otherwise disconnected programs,
with very little of each program hidden or secluded. This intensification of optical disjunction across programs is registered by a
glass wall at the shear line that serves to mitigate sound transmission. Vertical shear can generate intricate relationships between
the inside and the outside of a building at the top or bottom of a
shear rather than just around the perimeter, because the staggering of levels can carry through the building from the bottom to

Le Corbusier, Villa Baizeau, 1928

the top. Vertical shear requires limited change to the footprint or
boundary of the exterior walls and is often used to create internal
spatial difference for buildings on tight sites.
A horizontal shear maintains continuity in plan and some of the
logic of extruded floor plates, but produces spaces through the
interplay between setback and cantilever. While a vertical shear
directly impacts the interior, a horizontal shear largely affects the
exterior. Two other factors affect buildings with horizontal shear.
One is the degree to which the shear is applied systematically and
regularly to each floor. The other, which is usually directly related

A. J. Rynkus, Split-Level House, 1958

to the first, is the degree of similarity among the different floor
plates. Henri Sauvage’s designs for stepped houses, best exemplified by his apartment building at 13 Rue des Amiraux in Paris,
exhibit both a consistently repeated horizontal shear and relatively
equal floor plates, producing a series of terraces on the setback
side of the shear. In this raked diagram, one side of the building
is opened up to the sun and sky, while the other defines a space,
cast in shadow, between the cantilevers and the ground. Sauvage
placed two raked buildings back to back and filled the underbelly
with a swimming pool, effectively creating both private benefits
(terraces) and collective benefits (pool) through this one sectional
operation. This diagram was highly seductive, particularly for

Paul Rudolph, Beekman Penthouse Apartment, 1973

housing, as it injected into the model of the stacked slab tower in
the park both superior solar exposure / views and a space rife with
collective potential. It efficiently deployed repetition to produce
difference. Moreover, it made legible new part-to-whole relationships and allowed for greater continuities between the landscape
and the building. Horizontal shear was instrumental in a number
of projects and buildings, including Walter Gropius’s Wohnberg


(1928 proposal), Le Corbusier’s Durand Project (1933, Algiers),

Paul Rudolph’s Lower Manhattan Expressway (1972 proposal),

Horizontal Shear Sections

Denys Lasdun’s residence halls for University of East Anglia
(1962, Norwich, UK) and Christ’s College (1966, Cambridge, UK),
Ricardo Legorreta’s Hotel Camino Real (1981, Mexico City), and
more recently BIG /JDS’s the Mountain Dwellings. The Mountain
brings to fruition one of Sauvage’s century-old diagrams, which
situates parking beneath a pyramid of sheared housing. The fact
that the Mountain contains more parking than needed for the
apartments demonstrates that as the amount of the rake or the
angle is increased, thereby producing more exterior space for each
apartment, an engorged underside can result.
Horizontal shear can create collective social spaces when a
sequence of terraces are combined into a single open volume. The

Walter Gropius, Wohnberg proposal, 1928

Barnard College Diana Center by Weiss / Manfredi cleverly deploys
horizontal shear internal to the building mass to open up a series
of public lounges stitched together within a multistory academic
building, creating visual continuity on the diagonal through the
urban campus. Similarly, Neutelings Riedijk’s Netherlands Institute
for Sound and Vision takes full advantage of the spatial continuity created by horizontal shear, with the orientation of the shear
operating at ninety-degree angles below and above grade. The
entry lobby is connected visually to a series of stepped levels of
the building’s subterranean archive. The stacked floors above
are sheared in the perpendicular direction, opening up the main
space to daylight from the skylight, simultaneously creating a
multilevel exhibition volume at the top. The cumulative effect is a
ziggurat-shaped void carved from the building mass.
Repetitive horizontal shear on self-similar floor plates produces

Denys Lasdun, residence
halls, University of East Anglia, 1968

a combination of staggered exterior spaces, deploying corbeling
for stability. The use of horizontal shear in varying amounts creates
sectional moments around the full perimeter of a building, often
relying on a central core for balance. These moments are more
local than a repetitive raked section and can take the form of an
accumulation of platforms, balconies, overhangs, and skylights,
rather than collective spaces. Frank Lloyd Wright’s Fallingwater
is a good example of different-size floor slabs that are dispersed
to activate sectional effects on the exterior of a building. They
twist around the whole of the exterior of the building, producing
simultaneous sensations of upward growth and downward cascade,
while the interior is compressed, with space pushed horizontally,

Paul Rudolph, Lower Manhattan Expressway proposal, 1972

not vertically.
A pragmatic and frequently used sectional device, the hole is
a cut or penetration through a slab that exchanges lost floor area
for benefits in section. Holes are spatial commodities that can be
tactically deployed for vertical effects. They range in scale and
quantity from a single small opening between two floors to multiple
large atria that organize whole buildings.
Small holes accommodate infrastructural runs, such as risers,
ducts, and chase spaces; they are typically not large enough to

John Andrews, Gund Hall, Harvard Graduate School of
Design, 1972

impact the structural integrity of the floor. The shafts of elevators
and fire stairs are used to strengthen an overall structure, with


Hole Sections

solid walls often acting to resist lateral shear forces; they are
inserted within vertical holes precisely because these spaces are
not expected to produce visual continuity between floors.8 Small
holes through single floor plates can be strategically located based
on plan imperatives.
Large holes are more substantial voids in a multistory building,
creating spatial continuity among floors. These holes are predicated on some form of visual exchange and allow for light, acoustic, olfactory, and thermal continuity within a building. Holes
are a second order of sectional operation, acting on a given single
or multilevel stacked section.
A clear and basic manifestation of a hole at the scale of a room
is found in Le Corbusier’s Maison Citrohan, realized at the 1927
Weissenhofsiedlung exhibition in Stuttgart, Germany. Its central
organizing spatial component is the double-height void made by

Marie-Gabriel Veugny, la Cité Napoléon, 1853

cutting back a substantial portion of the second floor. In addition
to allowing exchanges of light, view, and sound, this hole establishes hierarchies between public and private, figure and ground,
and part and whole. There is a clarity and simplicity to this twostory section. It does not require a new construction system; it
just edits back the given structure. This scale of hole influences
the importance and hierarchy of spaces around it, creating, for
instance, formal double-height spaces. Lobbies, central meeting
areas, interior courtyards, and domestic living rooms all make use
of this type of program-specific scaled hole.9
Atria amplify the scale of smaller holes, in terms of both width
and quantity of floors, and exceed their effect. This increased
scale permits the effective distribution of daylight (often from skylights) and movement of air, and heightens the role of the interior.
Wright’s Larkin Building used the central atrium to organize and
focus the program of its offices, allowing sunlight in and assisting
with the mechanical distribution of air. Moreover, in this large
and sealed building, wisely separated from the din and soot of the

OMA, Très Grande Bibliothèque, 1989

neighboring rail yard outside, the atrium replaced the exterior as
the building’s focus.
At this scale, the atrium is less a cut through floors than a
space around which floors are built, a condition Louis I. Kahn
made explicit in the articulated structural lining of the atrium of
the library at Phillips Exeter Academy. In the asymmetrical Ford
Foundation Headquarters by Kevin Roche John Dinkeloo and
Associates, the atrium serves as a conditioned, four-season
garden, open to sunlight on the south and east sides. Offices

Jean Nouvel and Emmanuel Cattani & Associates, Galeries
Lafayette, 1996

on the north and west envelop the atrium, with selective use of
horizontal shear to terrace the ground and rooftop enclosure.
John Portman has pushed the use of the atrium to an extreme,
creating hotels that are defined by the radical dichotomy between
their conventional exteriors and spectacular interiors. The vast
atria of his interiors appear to extend upward infinitely, a sensation
heightened by exposed glass elevators accelerating past series
of stacked open walkways and balconies. The atrium of Portman’s

Steven Holl Architects, Simmons Hall, MIT, 2002

New York Marriott Marquis hotel is framed by thirty-seven stories
of rooms, stacked in groups of five floors that illustrate local


horizontal shear. The visual pleasure and spectacle of atria

account for their frequent use in places of consumption, notably

Incline Sections

department stores, as exemplified by Galeries Lafayette in Paris
of 1912 and Jean Nouvel’s design for the same company in Berlin
at the end of the twentieth century.
Holes are the key component of Toyo Ito’s Sendai Mediatheque,
striking an intriguing balance between their implications for the
plan and the legibility of the section. The building is organized
around thirteen holes, which puncture all seven floor slabs. The
holes serve as the locus of circulation; as mechanical shafts;
as tubes for the flow of energy, air, light, and sound through the

Le Corbusier, Villa Savoye, 1931

floors; and, paradoxically, as the building’s structure. These hollow,
inhabitable tubes made through bundled steel columns not only
produce the section but become primary plan components, choreographing the program on each floor. In the Sendai Mediatheque,
holes ringed by structure animate what would otherwise be a series
of repetitive and independent stacked floors.
Tecton, Penguin Pool, 1934

Inclines are sloped floor surfaces, which often connect levels.
Inclines change the angle of an occupiable horizontal plane,
thus effectively rotating plan into section. Unlike stacks, shears,
and holes, inclines blur the distinction between plan and section.
With inclines, sectional play does not require the sacrifice of a

Vilanova Artigas, Almeida House, 1949

portion of the plan. Like holes, their specific impact on section is
dependent on their scale; they can range from a narrow ramp to
a full floor to entire built environments, as envisioned by Claude
Parent and Paul Virilio in their oblique urban order. Le Corbusier
proposed the promenade architecturale, an itinerary through space
based on the continuity of the horizontal with ramps. In its first

Le Corbusier, Palais des Congrès, 1964

realization in 1923, with Villa La Roche–Jeanneret, a single ramp
cuts one level through a gallery. At this scale, the incline is more
of an object within a double-height space than a fully formed
component of the building’s section. This ramp has a stronger
impact in plan, where its curve highlights a bulge in the wall. In
comparison, the incline in Villa Savoye is much more instrumental
in organizing and activating the entire building as a promenade
architecturale. It connects space in, up, through, and out of the
two floor slabs, culminating in a roof garden atop the building.
However, the vertical space of section is truncated by the fact that
the ramp fills the area that was removed from the floors in order

Claude Parent and Paul Virilio, habitable circulation, 1966

to accommodate it. Moreover, the ramp moves from inside to
outside and is spatially disconnected inside the villa, where
Le Corbusier relied on the continuity of the wall adjacent to the
ramp to register the section. This reading is substantiated by the
section drawing for Villa Savoye included in his Oeuvre complète,
which is from an earlier scheme, in which that wall extended up
another floor. Somewhat ironically, a narrow ramp such as the one
in Villa Savoye produces more discontinuity than continuity in
plan. Even though the ramp is only four feet wide, it requires thirtytwo feet to make the connection between the two floors.10 The
incline viewed in the path of travel along the ramp creates continuity of section, but this comes at a price. In order to connect
different floors, the incline must also cut into the plan of the villa,


Incline Sections

creating a discontinuity of space. The ramp at the Villa Savoye
cuts the plan in two, distinguishing the garage from the entry hall
and the exterior terrace from interior bedrooms, while enabling
light and views to pass diagonally across the ramp.
This paradox of an incline creating continuity in section only
through discontinuity in plan was examined and explored by

Vilanova Artigas, São Paulo School of Architecture, 1969

Frank Lloyd Wright in two different projects. In the V. C. Morris
Gift Shop, a narrow ramp is aligned with an atrium, thereby
enhancing visual connections across the section and decreasing
the disruptions to the space from shear. Movement up and, more
important, around this incline adds to the spectacle of shopping.
While the incline in Villa Savoye is autonomous, as it splits the
column grid and penetrates through all floors, the incline in the
Morris Gift Shop appears to be hung from the balustrade of the
floor above, allowing the circulation on the ground floor to slide in
and around it. Because the Morris Gift Shop was an insertion into
an existing building, Wright’s play with the incline was constrained,
but he explored this theme further in the Solomon R. Guggenheim
Museum. In this well-known museum as spiral, Wright fuses an
incline and atrium, turning the main gallery floors into a single
continuous promenade. (Side galleries and support spaces have
flat floors and are located away from the central event.) Since
all floors merge into a single surface, the challenge for the viewer
is not an issue of sequence or passage but rather starting point.
Wright famously insisted that all visitors first entertain an elevator

OMA, Jussieu-Two Libraries (detail), 1992

ride to the top, with the downward slope of the incline facilitating
a leisurely walk. (Curators have not always followed Wright’s
commands when designing show sequences.)
Wright’s work on the Guggenheim draws parallels to his unbuilt
Gordon Strong Automobile Objective and Planetarium project,
where a double-helix ramp brings cars up and down. Designs for

OMA, Educatorium, 1997

roads and parking systems have deployed incline as a necessary
means of facilitating automobile passage. Ramped parking structures use inclines in two distinct manners: either as connecting
pieces among level floors of repetitively stacked parking or as
continuously ramped surfaces that merge parking and circulation.
The Guggenheim plays on the latter, while Herzog & de Meuron’s
1111 Lincoln Road explores the creative possibilities of the former,
introducing variations in floor height to transform a parking

Alberto Campo Baeza, Museum of Memory, 2009

structure into a social destination, complete with a residence
with sheared floor plates on top.
While Wright negotiates the paradox of the ramp creating
discontinuity by introducing the central atrium in the Guggenheim,
OMA deploys the incline to foster greater programmatic density
and to create visual juxtapositions. OMA’s Rotterdam Kunsthal
is a cut-back incline at the scale of a whole building. The shear
between two inclined surfaces is exaggerated and animates
programmatic misalignments, with a single incline that is split

Henning Larsen Architects, Harpa, 2011

by a wall of glass into an interior corridor moving up and an exterior path that threads through the center of the building. The
outer edges of this incline are pushed to the exterior and are
legible as elevations. OMA’s unbuilt project for Jussieu (1992)


is organized around a continuous incline, which, like the

Guggenheim, eradicates floor-to-floor distinctions. But unlike

Nest Sections

at the Guggenheim, the width of the incline expands and contracts
and, more important, tactically deploys discontinuity within that
surface through cuts, folds, and shears, to allow for a multiplicity
of programs and spaces on the same continuous surface.
Although one objective of a continuous inclined surface is an
activation of the section, the consequence is not necessarily
an intriguing vertical space. This is because an inclined surface
often folds back on itself, effectively forming a stacked section
with unlevel floors. In these projects, vertical extensions of space

Cedric Price, Fun Palace, 1964

are produced by editing back or removing parts of the floor, as
in the Guggenheim’s atrium or the vertical shafts in the Kunsthal
or Jussieu.11 Continuous inclined surfaces often exhibit shear
and need holes for visual continuity. This is clearly evident in
Henning Larsen’s Moesgaard Museum, where the shape of the
building is defined by its inclined, sloped green roof. Whereas
the incline is obvious on the exterior, it is primarily visually apparent within the interior when viewed through a large hole for the

Le Corbusier, Heidi Weber Museum, 1967

building’s oversized staircase.
Nests produce sections through interplay or overlap between
discrete volumes. Whereas stack, shear, hole, and incline work
primarily with flat plates, a nest positions three-dimensional
figures or volumes for sectional effect. The early twentieth-

Buckminster Fuller and Norman Foster, Climatroffice, 1971

century houses of Adolf Loos often demonstrate volumetric
nesting, with rooms stacked on various levels to create complex
spatial sequences, typically described as Raumplan. The spatial,
structural, or environmental performance of the nest usually
exceeds that of the volumes operating in isolation. Crucial in
this approach to section is the functionality of interstitial space
and its relationship to the exterior skin. Although the permutations of a nested section are numerous, a handful of examples
will help explicate two significant variations.
To create the Center for Arts in La Coruña, Spain,
aceboXalonso Studio lodged a series of highly specific perfor-

Jean Nouvel and Philippe Starck, Tokyo Opera House, 1986

mance spaces as distinct but interconnected forms within a box
formed by a multilayered skin. The resulting interior is a complicated vertical space that moves around the volumes. The volumes
are programmatically specific, whereas the space of the section
between is indeterminate, fluid, and undefined. As the performance spaces press up against the exterior, the double skin

Bernard Tschumi, Le Fresnoy Art Center, 1992

of the shell is interrupted, thus making visible on the outside the
nesting of the volumes in section. MVRDV’s Effenaar Cultural
Center is based on a more pragmatic approach. Individual rooms,
each with its own size and function, are arrayed around the exterior of the building’s skin, in effect increasing the thickness of
that skin. These generate a doughnut in section, with a main

FAR frohn&rojas, Wall House, 2007

concert hall as the center of the doughnut, thereby linked to all
the individual programs in the building. Whereas aceboXalonso
begins with a large frame into which smaller programs are nested,
MVRDV organizes the nested volumes to create the overall figure,
building the whole from individual parts.


Vertical circulation in these and other nested projects is a key
design challenge, as stairs run the risk of disrupting the tight set
of adjacent volumes. In Loos’s designs, stairs are woven in and
among nested volumes, becoming at times part of a sequence
of the vertical staggering of volumes and at other moments hidden
and tucked away, existing in the space between rooms. With the
Effenaar Cultural Center, MVRDV simply moved the circulation
and fire staircases to the exterior, where they exist as independent
spaces attached from outside.
MVRDV’s 2001 proposal for the Eyebeam Institute is a more
nuanced and intricate approach to nesting. As with Effenaar,
individual program pieces are dispersed in section, but here they
Richard Rogers, Bordeaux Law Courts, 1998

are separated from one another. The consequence is a complex
interstitial void punctuated by the shapes of those program pieces.
Moreover, the exterior skin, which doubles as structure, extends
around these pieces into the building volume, effectively bridging
between pieces and stiffening the exterior structure. Apertures
on the exterior of the building replace the structural skin where
the interior volumes kiss that skin. The specificity of these nested
interiors’ programs is visible on the exterior, yet this specificity
is occluded from view within the larger building cavity. As with the
two previous projects, the interstitial space is programmatically
indeterminate, permitting unforeseen activities to be catalyzed by
the spatial stimulation of an open and compelling section.
These previous three examples all deploy discrete volumes adjacent to one another to activate an interstitial section. A different
category of nesting occurs when discrete volumes are lodged inside
one another. Although the logic of this type of nesting would seem
to undermine the development of section, this redundancy, when
intelligently deployed, can intensify the programmatic relationship
between the volumes. It can also produce new models of thermal
performance based on a complex relationship between exterior and
interior conditioned spaces. A small-scale example of this type is
Charles Moore’s own house in Orinda, California, from 1962, where
the volumes of the sitting area and the shower, each marked by
four columns and a skylight, are caught within the overall shell of
the small house. These “aedicules” invert both the normal structure of the house and the conventional location of the bath, which
here is open to the whole house. These nested volumes become
the primary structure of the house, allowing its exterior corners to
disappear as sliding doors. Counterintuitively, this nesting sponsors
greater openness and connection between the exterior and the
most private interior. A different manipulation of the expected logic
of nesting is found in the San Paolo Parish Complex in Foligno,
Italy, by Fuksas Architects. Large, hollow sleeves structurally connect the two volumes, suspending the inner volume and channeling
sunlight into this innermost space, bypassing the outer volume.
The contrast in both the volume and illumination of the section add
dramatic effect to the church. Nesting is a particularly good sectional device for manipulating and controlling daylight through

MVRDV, Eyebeam Museum of Art and Technology, 2001

multiple layered skins, a technique used by Gordon Bunshaft of
Skidmore, Owings & Merrill at the Beinecke Library. Here a box of


translucent stone protects rare books from the damaging effects

of direct sun, while placing them on dramatic display within their

Hybrid Sections

own internalized glass vitrine, nested inside the exterior envelope.
An extremely literal example of a nested section is Sou
Fujimoto’s House N. The three rectangular layers of this house
are all white, contain self-similar rectangular framed openings on
all five sides, and diminish only slightly in thickness from outerto innermost. Yet, by locating the thermal enclosure on the middle
layer and by pushing the outer skin to the limits of property,
Fujimoto conscripts the grounds as the site of a surprisingly

Karl Friedrich Schinkel, Altes Museum, 1830

complex homogeneity that blurs conventional distinctions between
interior and exterior, private and public. Although all the layers
look alike, each does different things: the outer defines the precinct of the house; the middle regulates the thermal environment;
and the inner distinguishes bedrooms from the living /dining area.
Each alone would be too porous, but collectively they regulate
privacy and view. Nonetheless, the layers do little to increase the

Charles Garnier, Paris Opéra, 1875

environmental performance of the house, as it is only the middle
layer that acts as the thermal barrier. In contrast, the Mont-Cenis
Training Center by Jourda Architectes uses sequential nesting to
enhance thermal performance. Two unremarkable linear buildings
are located under a very large wood shed, which spans beyond the
footprints of the inner buildings. Clad in glass and photovoltaic
panels, the outer skin uses passive solar and ventilation to modify
extremes in weather, producing a temperate thermal layer between
the outside and the two inhabited buildings. Neither fully inside
nor fully outside, this space is conceptually and functionally akin

Adler & Sullivan, Chicago Auditorium Building, 1889

to the cavity between two panes of glass in a thermal window.
Furthermore, nesting makes possible a gradient of thermal conditions directly linked to the complex interplay of space, building
materials, and thermodynamic forces in section. Mont-Cenis
Training Center is a more refined elaboration of the exterior thermal or climate utopias envisioned by Buckminster Fuller. Whether
in his conceptual dome to encapsulate Manhattan or the United
States Pavilion at Expo ’67 in Montreal, Fuller repeatedly used
nested section to generate controlled thermal environments. These

Frank Lloyd Wright,
Gordon Strong Automobile Objective, 1925

large-scale nested sections were the product of his exploration
and innovations in space-frame construction systems, which allow
for the building of expansive envelopes, facilitating the placement
of buildings within buildings.
Extrusion, Stack, Shape, Shear, Hole, Incline, and Nest are
primary methods for operating in section. For the sake of clarity,
they have been presented as distinct modes, but they rarely operate in isolation. Hole and Shear, for instance, require the existence of extruded floors or stacked sections to register the action.

Erik Gunnar Asplund, Stockholm Public Library, 1928

Shaped sections typically couple with stacked plates to provide
sufficient support and service spaces. Indeed, buildings exhibiting
the most complex and intricate sections contain all manners of
combinations. We have included projects that exemplify innovative
combinations of section types, often in creative tension; where
no single dominant type is in evidence, we have designated these
projects Hybrids.


Hybrids exhibit instructive strategies for combining sections.
A basic strategy is the juxtaposition of two very different section
types where neither is dominant. Michael Maltzan’s design for the
Star Apartments, for instance, joins stacking and nesting. The
concrete podium with residential floors above establishes stack
as a key sectional approach. Yet the modular construction of the
individual apartment units dictates a nested approach within
Alvar Aalto, Art Museum in Baghdad, 1958

the upper stacked system.
Other hybrid projects synthesize sectional strategies so seamlessly that understanding their intersection of systems requires
close examination. The Villa Girasole—with its lightweight rotating
top that is set on a rusticated base and connected through an
eight-story spiral stair tower—demonstrates nested forms on
top of one another, stacked floors that compose the house and
occupiable base, and a sizable hole in the figure of the spiral
staircase. The overall building is sheared horizontally by the landscape, with the atrium stair tower providing continuity between
upper and lower gardens. In Herzog & de Meuron’s VitraHaus,

James Stirling, James Gowan, and Michael Wilford,
Leicester University Engineering Building, 1963

shaped volumes are nested into each other, stacked together, and
then sheared horizontally to produce an exterior atrium. Arguably
the most synthetic project, demonstrating multiple merged section types, is SANAA’s Rolex Learning Center, where a simple
extrusion is continuously shaped, creating inclined surfaces and
intersecting with a series of discrete holes to reveal the project’s
deformed section.
Not surprisingly, multistory buildings that are organized

Arata Isozaki, Oita Prefectural Library, 1966

vertically often are case studies for creative approaches to section.
From Herzog & de Meuron’s Prada Aoyama to Kengo Kuma &
Associates’ Asakusa Culture and Tourism Center, the basic strategy of vertical stacking is challenged and complicated by alternative sectional interventions. Shaped volumes containing changing
rooms are nested within the stacked levels of the Prada department store, all enclosed in a shaped box or volume. In Kuma’s
design, individual shaped forms containing nested volumes within
volumes, complete with inclined floors, are placed on top of one
another to form a tower.
Complex public or cultural buildings are most often the site
for sectional intricacy. These projects often include combinations
of program-specific spaces that require the integration of discrete

John Portman, Hyatt Regency San Francisco, 1974

shapes or figures within a given envelope. Theaters, concert halls,
and other performance spaces have stages and sloped auditoriums that figure prominently, requiring complementary circulation
systems and support floors, as exemplified by OMA’s Casa da
Música. Similarly, multifunction academic and civic buildings,
including Mack Scogin Merrill Elam Architects’ Knowlton School

Denys Lasdun, Royal Theater, 1976

of Architecture, OMA’s Seattle Central Library, Álvaro Siza’s Iberê
Camargo Foundation Museum, Morphosis’s 41 Cooper Square,
NADAA’s Melbourne School of Design, Diller Scofidio + Renfro’s
Museum of Image and Sound, and Grafton Architects’ Università
Luigi Bocconi, all use section to create inventive works of architecture that resolve complex programmatic assemblages.
By incorporating a range of distinct sectional approaches


within a single building, these projects provide a rich source of

study and investigation. While the works used to exemplify one
type of section were selected because of their ability to clarify
and distill a given approach, they do not always illustrate the
spatial play of the hybrid combinations. The interplay of two or
more approaches to section gives architects the capacity to
not only accommodate complex programs but develop projects
that are multilayered. This does not mean, though, that all
projects that use more than one type of section are necessarily
interesting or compelling works of architecture. Rather, the
exploration of the variety and complexity of hybrid approaches
demonstrates the expansive range of possibilities of the heuristic
structure of section types. The classification system is used
not to constrain but to catalyze architectural discourse.

Charles Correa, Kanchanjunga Apartments, 1983

Excerpts from
a History of Section
Given its extensive use in architectural practice today, the section
arrives surprisingly late in the history of architectural drawing.
In fact, while individual instances of sectional drawing were in

Steven Holl Architects, American Library Berlin, 1989

evidence by the early part of the fifteenth century, section as
a codified drawing type did not complete the triumvirate of plan,
section, and elevation in European architectural academies and
competitions until the late seventeenth or early eighteenth century.12 While it is beyond the scope of this essay to map a comprehensive history of the architectural section over the course of
the last several hundred years in the West, it’s instructive to frame
the major changes in the conceptualization and deployment of

Mecanoo Architecten, Technical University Delft Library, 1997

section in order to contextualize its current status and potential.
What follows is a series of episodes that coalesce around
several key ideas. Discontinuous and incomplete, these moments
reveal the potentials and paradoxes of the section. Primary among
these contradictions is the dual nature of the term section itself.
When we speak about section we mean both a representational
technique and a series of architectural practices pertaining to the
vertical organization of buildings and related architectural and
urbanistic constructions. These conditions are interrelated both
historically and professionally. Although the two meanings of the
term are often used interchangeably and fluidly, we will attempt to
clarify this relationship in order to examine the historical trajectory of the section, from its origins as a representational mode to
its development as a set of design practices with spatial, tectonic,
and performative implications.
The origin of section as a representational mechanism, while
obscure, has typically been associated with its capacity to reveal
the hidden workings of an existing building or body—often as
a retrospective or analytical technique. The earliest surviving

Neutelings Riedijk Architects, Museum aan
de Stroom, 2010


drawings that tentatively depict conditions of an architectural
section are Villard de Honnecourt’s parchment studies of medieval
cathedrals from the thirteenth century.13 Among the sixty-three
pages of his known drawings, which range broadly in subject matter, are hints of a cut through the exterior wall of Reims Cathedral,
shown to the side of a drawing primarily intended to illustrate the
sequence of flying buttresses shown in elevation. Indeed, while
Honnecourt’s drawing is orthogonal and made through clean lines,
the section as a cut is tentative and incomplete, acting as a side
note to the depiction of structural complexities that merge with the
qualities of the architecture in the Gothic cathedral. Nevertheless,
this early example presages one of the predominant uses of the
sectional drawing—as a means to analyze and represent structural
and constructional relationships visible only through the delineation of a building’s vertical organization.
While Honnecourt’s drawing suggests that section was not
wholly unknown in architectural circles prior to the Renaissance,
its rise as a codified form of representation has been linked to
Villard de Honnecourt, Reims Cathedral, ca. 1230

two related precursors that originate from outside architecture
proper: the observation of archaeological ruins and the biological
description of the human body.14 In both instances, section is
explicitly associated with the visual and physical dissection of an
extant body, whether constructed or organic. As such, section
originates as the drawn record of an observed material condition
first and as a representational mechanism only in retrospect.
Jacques Guillerme and Hélène Vérin’s article “The Archaeology
of Section” traces the origin of the architectural drawing to the
observation and subsequent depiction of Roman ruins and to

Donato Bramante, Roman ruins, ca. 1500

the physical breaks and discontinuities in decaying structures.15
These fragmented monuments provided a view that simultaneously
exposed interior and exterior to the eye of the touring architect
or artist. According to Guillerme and Vérin, the practice of recording through drawing these surviving monuments in their state
of romantic decay gave slow birth to the section as a conscious
projection of architectural intentionality, “transforming the observation of archaeological remains into the observance of architectural diagrams.” The section understood as an imaginary cut
through an otherwise solid building or as a means of describing

Giuliano da Sangallo, Temples of Portumnus and Vesta, 1465

a future construction comes only after the documentation of
ruins that reveal what would otherwise be hidden. This translation
necessitated a conceptual shift from a literal depiction of a
fragmented building to an abstract device: the imaginary plane
of the sectional cut. The conventional nature of this transformation
is recorded in the variety of techniques used to make explicit the
operations of the cut, ranging from the device of rendering new
or projected buildings in quasiruined form to the emergence of

Leonardo da Vinci, study for central plan church, ca. 1507

poche as a method for depicting the conceptually solid structural
fabric of a building.
A parallel set of antecedents can be found in artistic and
scientific practices depicting the body and its internal organs that
evolved from the physical dissection of human remains and
from investigative anatomy as it emerged in the fifteenth century.


As with the architectural section, these drawings often relied

upon an inventive array of visual devices to render explicit the
sectional nature of the cuts. The most often cited are Leonardo
da Vinci’s obsessive studies of the human form, including his
drawing of a human skull, which combines aspects of plan, elevation, and section in a cutaway perspective. Leonardo’s depiction
of a cranium was not unlike that of the dome in his contemporaneous study for a circular library, both demonstrating the
act of cutting as essential to simultaneously show exterior and
interior conditions of the body or building.
In perhaps the most famous of these early medical examples,
Andreas Vesalius’s De Humani Corporis Fabrica (1543), the variously skinned and flayed bodies are depicted in poses that mimic
those of living and allegorical subjects. These woodcut illustrations are intricately constructed, not only to display the internal
structure of muscles and viscera but also to acknowledge the
act of cutting as both a physical operation and a representational
conceit. Figures adopt stances that help to demonstrate the
anatomical systems on view—but also fancifully seem to partici-

Leonardo da Vinci, Skull, 1489

pate in their own dissection and display.
While it may be difficult to verify any causal relation
between these biological depictions and architectural practice,
it is nonetheless possible to identify productive similarities
whereby techniques applied in one sphere reappeared in the
other, suggesting a cross-fertilization of graphic techniques
and modes of representation. More important, however, drawing
techniques derived from both archaeological and anatomical
practices strongly indicate that section originated as a retrospective rather than prospective tool, an analytical device rather
than a generative instrument. It is perhaps this origin in the
recording and revealing of extant conditions that has accounted
for the slow integration of section as a productive instrumentality in architectural practice.

Andreas Vesalius, drawings, from De Humani Corporis
Fabrica, 1543

Sectional drawing as an explicitly architectural technique appears
in the work of Italian architects in the latter half of the fifteenth
century. At this time a renewed interest in documenting the
sectional ruins of classical antiquity intersected with the use of
section for speculating on the structural and material properties
of ancient buildings that had not deteriorated, as well as for
describing new constructions and projects. The Pantheon, built
by Emperor Hadrian in AD 128, was a frequent subject of inspired
conjecture, with speculative section drawings executed in the
hope of ascertaining the structural and proportional logic that had
kept it intact.16 It offered to architects a powerful subject for the
use of section, given the seductive cut in the illuminating central

Bernardo della Volpaia, Pantheon, from Codex Coner,
ca. 1515

oculus of the dome. Instead of a sealed dome, the Pantheon
displayed a provocative void, allowing interior and exterior space
to merge in a manner that would typically be seen only through
a section drawing.
Early collections of Renaissance drawings (such as the Codex
Coner, the Codex Barberini, and the sketches of Baldassarre


Peruzzi) contain numerous sections, including different interpretations of the Pantheon as well as views of contemporaneous
centralized churches. These drawings seek, through an imaginary
cut, to trace the exterior and interior profile of the wall, thus
visualizing the relationship between the building’s form and the
space it contained. Even in these early drawings the status of the
section as a form of architectural representation was in question,
as the mapping of the substance of the wall was only a part of
the image. As Wolfgang Lotz noted in his essay “The Rendering
of the Interior in Architectural Drawings of the Renaissance,”
section drawings developed not as a singular and fully codified
practice but as a series of incipient operations that overlap and
combine in promiscuous ways.17 For Lotz, the question was less
the status of the section cut itself than the role this drawing type
was to play in either staging interior scenes or recording architectural measure and proportion. In the Codex Coner (a drawing
set now attributed to Bernardo della Volpaia and dated to the early
Bernardo della Volpaia, Tempietto, from Codex Coner,
ca. 1515

1500s) the view within the sectioned walls is depicted through
a single-point perspective. This painterly approach sacrifices
dimensional accuracy for the illusion of a scene visible beyond
the cut plane of the section. In contrast, certain sections in the
Codex Barberini (attributed to Giuliano da Sangallo) and in the
Pantheon drawing by Peruzzi demonstrate a commitment to orthographic projection, where the space beyond the cut is shown in
elevation with no vanishing point or perspectival distortion.
While explicitly spatial, the sectional perspectives of the
Codex Coner represent a highly particular notion of space, both
adapted to and in part determined by the logic of the drawing
type itself. The architectural historian and critic Robin Evans has
argued that the inherent logic of the section drawing is heavily
biased toward bilaterally symmetrical and axial spatial organizations, which are readily depicted through this technique. Moreover,
the centralized and frontal sections of the Codex Coner imply an
understanding of space that is conceived volumetrically but also
from the perspective of a static observer taking in the architecture
as a pictorial composition. In this reading the perspectival section
reinforces a notion of architecture as a principally optical phenom-

Giuliano da Sangallo, centralized building, from Codex
Barberini, ca. 1500

enon, and one tethered to a fixed viewpoint.
By contrast, in later drawings of the Codex Barberini and the
work of Peruzzi and Antonio da Sangallo the Younger, the observer
is progressively removed as a subject through the use of more
orthogonal representational conventions in the depiction of section. These drawings abandon the optical distortions of perspective, resulting in a technique that can eliminate the subjective in
favor of objective accuracy. This can be understood as a necessary
development of the section drawing as a professional document,
capable of conveying in unambiguous terms the dimensional and
geometric information required by the builder. It is significant

Antonio da Sangallo the Younger, St. Peter’s, ca. 1520

that this transition coincided with Sangallo’s and Peruzzi’s participation in the fabricca of St. Peter’s under Raphael and the emergence of new hierarchies of building production that separated
the architect from building. In Lotz’s view this shift also leads to


the possibility of more complex, dynamically conceived spaces,

no longer restricted by the single static observation point of the
Codex Coner.
Lotz makes a claim of evolutionary teleology from the earlier
perspectival practices to the emergence of the strictly orthographic
section. The perspectival section is principally an illustrative
practice, one that maximizes the visual appeal of a singular image
to convey both profile and space and combines the quantifiable
with the perceptual. The orthographic section, on the other hand,
is an instrument of metric description connected to the emer-

Baldassarre Peruzzi, Pantheon, 1531–35

gence of codified forms of construction documentation. However,
its increase in accuracy requires a multiplication of drawings to
provide the requisite information to comprehend complex spaces
and architectural assemblies, as the absence of illusionistic depth
flattens the legibility of spatial relationships.
This progressive bifurcation of orthographic section drawing
from perspectival practices coincides with architecture’s increasing divergence as a discipline from the other fine arts during the
sixteenth century, as exemplified in the work of Sebastiano Serlio.
The increasing use of the dimensionally accurate orthographic
section, complete with notations of construction logic, parallels
the emergence of the professional architect as distinct from the
master craftsman. Whereas elevations describe the image and
composition of architecture, a section is an instrument of instruction, conveying to the builder the means and profile of erection.
Of the three primary orthographic drawing types—plan, elevation,
and section—it is section that aligns most closely to structural

Sebastiano Serlio, Project N13, from Book VII of On
Domestic Architecture, ca. 1545

and material designations. The typical orthographic section is in
many ways the most sophisticated, combining in one image two
types of representation: the objective profile marking the cut and
the interior elevation beyond, describing the inhabitable space
made possible by the inscribed wall.19
The section’s place in the standard repertoire of orthographic
representations is in clear evidence by the time Andrea Palladio’s
Four Books of Architecture was published in 1570.20 Here building
sections are paired with exterior elevations, each drawing type
describing only half of the building and aligned through the use
of only orthographic information. Interior perspectives that might
better convey the experience of the work are suppressed in favor
of measurable facts, reinforcing the conception of the architect
as the organizer of geometry. The symmetry of Palladio’s work
enables this efficiency, which reduces the number of engravings
necessary to illustrate a building completely. With this pairing
the exterior elevation sits in juxtaposition to the interior elevation,
the section serving to reveal the interplay between the shell of
the building and its interior disposition. In Palladio’s work the distinction and similarity between the section and the elevation are
deployed to full effect. While sharing the profile of the building,

Andrea Palladio, La Rotonda, ca. 1570

the elevation illustrates the composition and order of architecture,
legacies of architecture as an aesthetic art. Section reveals the
material and mass necessary to construct the edifice, knowledge
unique to architecture as a profession aligned with the craft of
building. Palladio’s section-elevation hybrids exemplify the dual
nature of architecture as an art and a craft and illustrate the


synthesis of the exterior and interior as quintessentially the
domain of the architect.
It is important to note that the load-bearing obligation of the
wall meant that for Palladio and his contemporaries, the shapes
of the wall, floor, and ceiling were coincident with the structural
system. Yet if we compare the plan and the section, the very
same wall is rendered in completely opposite ways. In plan, walls
are solid, filled in to reinforce the legibility of the organization
of rooms and spaces, which are left blank. The walls in section
are white, left as voids between the highly articulated interior
surfaces beyond. The plan is the privileged architectural figure,
with alignment between wall and spatial concept heavily marked.
On a page, the plan dominates, setting the primary terms by
which the building as an architectural composition is to be read
and understood. In contrast, the material condition of the wall
in section is left as a void, a gap between rooms. While the plan
may organize, the section affords greater play among the shape,
form, and organization of the material being cut and the inhabAndrea Palladio, baptisterium of Constantine, 1570

itable architectural space framed by it. Ceilings curve to disperse
gravitational load over the large volumes; invisible roof trusses
are given the same weight as the floor of the piano nobile; and the
scale and size of each building are most clearly evident in section.
It is the particular instrumentality of the section that allows for
the simultaneous registration of both form and effect, providing a
unique means for exploring, testing, and understanding complex
interactions and exchanges of material and space.
Nearly two hundred years after Palladio, the section drawing
continued to increase in importance as a comprehensive means
for conveying architectural effects, even though structural obligations remained consistent. It is perhaps in the unbuilt scheme
of Étienne-Louis Boullée for the cenotaph for Isaac Newton of
1784 where section is deployed in full, illustrating its potential
to choreograph the relationship among architecture, human
inhabitants, and site. While Boullée’s project was depicted in

Étienne-Louis Boullée, cenotaph for Isaac Newton, 1784

plan, elevation, and section, it is sectional drawings that convey
the full force of the project. Two sections, one depicting daytime
and the other night, capture fully the experiential inversion
intended by the design. During the day, the interior of the massive
sphere would be illuminated by cuts through the exterior walls,
creating the impression of a captured night sky. At night, the
inverse would occur, with a massive illuminated orb transforming
the interior space into a daylit room.
Only through section drawings is the temporal juxtaposition
between the constructed world within the architectural sphere and
the natural world outside made visible. While the materiality of
the building is never revealed, the tonal marking of the foundation,
walls, and shell shifts to align with the pictorial goal of each
section. A light section tone in the daytime image reveals conical

Étienne-Louis Boullée, conical cenotaph, ca. 1780

cuts that penetrate the massive structure to create the illusion
of night, whereas in the nighttime image, the section blends into


the evening sky, retreating from consideration in deference to

the power of the manufactured light source. Despite the absence
of any perspectival projection, Boullée’s section clearly demonstrates the capacity to convey experience over tectonic designation, aligning with his conviction that architecture should not be
bound by obligations of building but premised on the embodiment
of ideas. Paradoxically, section, the very drawing type now most
associated with the materials of construction, was deployed by
Boullée for the opposite purpose, illustrating succinctly its multivalent potential.
In large part, constructions through the seventeenth century
consisted of space circumscribed by masonry mass, resulting in
sectional depictions in which exterior profile and interior space
were closely interrelated through the thickness of the poche. However, during the eighteenth and nineteenth centuries, the solid
wall of load-bearing masonry architecture was challenged by an

Eugène-Emmanuel Viollet-le-Duc, vaulted room, 1872

increasingly layered set of conditions, reflecting new structural
technologies associated with the emerging materials of cast and
wrought iron. In this context the section gained enhanced currency
as an effective means for describing and analyzing architectural
form, understood as a direct expression of static forces. Of particular significance in this regard are the writings and drawings of
the French architect and theorist Eugène-Emmanuel Viollet-le-Duc,
who relied on the section to demonstrate the interdependency
of formal and structural systems that were not only central to his
ideas but key tenets in the development of modern architecture.
Viollet-le-Duc set his work in direct juxtaposition to the
teachings of the École des Beaux-Arts, which had focused on
composition and plan. In his Lectures on Architecture, Violletle-Duc outlined his goal to rethink Gothic architecture in order to
adapt what he saw as its exemplary structural rationality to the

Eugène-Emmanuel Viollet-le-Duc, medieval and modern
methods for supporting a projecting gallery, 1872

new materials and constructional potentials of his time.21 The
Lectures are an expression of principles derived from the practices of previous eras, illustrated with sectional engravings.
Rather than describing buildings per se, Viollet-le-Duc presented
these engravings as a series of case studies that translate the
masonry-based architecture of the past into the new expression
proper to the nineteenth century. Viollet-le-Duc’s comparative
rendering in “Lecture XII” of medieval and modern methods for
supporting a projecting gallery, for example, depicts the replacement of heavy stone corbeling by an iron strut. The efficacy
of this methodology is described in the language of efficiency
and economy: he writes, “We shall effect a saving in expense
and shall obtain a building that will present greater security, will
be less weighty, and will allow a better circulation of air about
the ground floor.”22 His ideas are supported by the didactic
nature of the section and its capacity to convey economically

Eugène-Emmanuel Viollet-le-Duc, structural system, 1872

the dynamics of structural and other gravitational forces, from
drainage to ventilation, in their relation to built form.
A related drawing by Viollet-le-Duc, from the same lecture,
depicting a “novel method of resisting the thrust of vaulting,”


offers another example of section as a didactic and projective
tool. Addressing the problem of the flying buttress, Viollet-le-Duc
replaces the masonry mass of the Gothic buttress with a system
of oblique iron struts, bars, and plates intended to resist the outward thrust of the masonry arches above. Importantly, the drawing
includes not only the physical form of the new hybrid construction but also the geometry of its structural relationships, thus
transcribing both the material and immaterial into a single reprePhillipe Bauche, Coupe de la Ville de Paris, 1742

sentation to demonstrate the isomorphism between structural
logic and architectural expression. Significantly, in none of these
instances does Viollet-le-Duc provide a plan, as the principles
involved relate primarily to the vertical dimension, where gravitational forces and static relationships hold sway.
These drawings also capitalize on the capacity of the section
to reveal the constructional condition of the building as an
assembly of constituent parts. Only through section could Violletle-Duc visualize the new architectural conditions he espoused:
“We no longer have, as in Roman architecture, concrete and
homogeneous masses, but rather a kind of organism whose every

Eugénio dos Santos, street section, 1758

part has not only its purpose, but also an immediate action.”23
This shift from an architecture based on mass to one of discretely
adapted parts prefigures the impact of industrialized production
and the technologically driven constructional efficiencies that
were to come to fruition in the twentieth century. It is also a conception of architecture that is effectively revealed through the
device of the section. Since structural assemblies operate first
and foremost in the vertical dimension, from foundation to column
to arch to roof, the section displays these transferences of force
and the corresponding building components in the most direct
form. For Viollet-le-Duc, the section drawing becomes a transparent demonstration of the inevitability of architectural forms

Pierre Patte, street section, 1769

derived from the tectonic systems of new materials.
The adoption of industrialized construction techniques and
materials changed fundamentally the nature of architectural
practice, with the use of steel and iron columnar and long-span
systems uncoupling the enclosure wall from structural obligations.
Paradoxically, the same technological advances that made possible this interdependence of structure and form announced by
Viollet-le-Duc set in motion the terms of their eventual disengagement within the modernist movement. The very efficiency of
steel (and subsequently concrete) construction systems, which
allowed them to work independently from exterior form and
interior space, placed the section, understood as both a representational technique and a location of architectural practice, in
a simultaneous point of liberation and crisis. The section, freed

Eugène Hénard, illustration of the “Street of the Future,”

from alignment with structural forces, could take on a new role
in regard to the manipulation of space. Simultaneously, the
section’s responsibility was challenged by the proliferation of
repetitive columnar systems and concrete slabs, removing for all
but long-span projects the obligation to sculpt gravitational forces
through section as a driver of design. Freedom of form came
through the loss of the structural or tectonic imperative that had


previously informed the logic of section.

With the growth of the metropolis that accompanied rapid industrialization, section evolved as a critical tool for understanding
an increasingly complex layering of architectural, transportational,
and hydrological systems. With urban density came the need for
a network of interconnected systems to deliver the various services
of the modernizing city. While master plans provided the means
for organizing territory, allowing, for instance, the mapping of
Manhattan’s grid or the reworking of Paris’s streets, boulevards,
and parks, it was through the use of the urban cross-section that

Grand Central Terminal, New York, published in the
Scientific American, 1912

the increasingly important, yet invisible, operations of the city
could not only be made visible but projected as an expansion of
political control. Executed not as a recording of existing conditions but as a speculative image of the future, the street section
demonstrates the power of this mode of representation to orchestrate divergent systems, opening new conceptual and spatial
territory for development.
The drawings of the Portuguese engineer Eugénio dos Santos
and those of the French engineer Pierre Patte are considered
the earliest uses of section to organize and understand the metropolis conceived as a set of interconnected infrastructural systems.24 Of the two, Patte’s work is better known, given its influential role in transforming Paris. Executed in the 1760s, his urban
plans and drawings proposed changes to the city and used
section to demonstrate the integration of the inner workings of
buildings, engaging the depth of the street as a site of future civic
improvements.25 Here the section reveals and organizes systems,

Harvey Wiley Corbett, “City of the Future,” 1913

unifying the interior of dwellings with the vast network of a shared
waste system. Patte’s drawings link the civic machinery of the
waterworks with the interiors of the adjacent apartment buildings,
suggesting the intimate connections between individual domestic
lives and the sanitary infrastructure that ties them to larger urban
networks. It is only through the use of the section that these
two divergent aspects of the city can be understood and visualized as one system, obscuring boundaries of ownership and civic
authority through the logic of the drawing. Patte gave greatest

Peter Cook / Archigram, Plug-in City, Max Pressure Area, 1964

focus to the integration of building and street drainage into a
shared collection tube, paying careful attention to the depth and
materiality of the sewer to ensure the proper durability, slope,
and water flow. By contrast, the architecture above the basement
level is left blank, undifferentiated, and underdeveloped, a placeholder designating only future inhabitation. The street monument
in the distance is given more attention than the buildings in
section. As such, the design concept of Patte illustrates the two
distinct trajectories of the urban section, one representing the
increased complexity and layering of the city and the other the

Chicago Central Area Transit Planning Study, 1968

density made possible by an architecture of repetitive stacking.
Presented in 1910, Eugène Hénard’s “The Cities of the Future”
draws directly on the precedent set by Patte.26 Hénard continued
to use section to stitch together visible and unseen operations.
Apprehending the challenges cities faced with the promise and
potential of new transportation systems, he envisioned the city as
a multilayered matrix of tunnels, tracks, and elevated railroads


that used section to thicken the very ground of the urban condition.
Here coal carts render visible the connections among individual
buildings and new infrastructural systems to provide power and
energy. Amid exuberant embellishments such as vertical shafts to
lift personal flying devices and automobiles, Hénard draws a series
of stacked domestic spaces, ordinary and repetitive, capped in
height only to allow sunlight to reach adjacent buildings.
Section drawings were instrumental in the thinking of modernist planners and architects like Hénard, as they transformed
the ground into a foundation for a densely layered metropolis,
accommodating emerging and often competing technologies
William Le Baron Jenney, Fair Store, 1891

of transportation and communication through distinct strata. The
use of section was essential to the conceptualization of the city
to come. From Corbett’s City of the Future (1913) to plans for
Grand Central Terminal in New York (1912) to Le Corbusier’s Ville
Radieuse (1924), visions of the future were coincident with the
image of the city as a multilevel stage, thus leveraging section’s
capacity to hold in opposition contrasting or even contradictory
programmatic conditions in a single view or space.
While the infrastructures of the city have grown in complexity,
from the eighteenth-century emphasis on hygiene and health to
the twentieth-century commitment to transportation, power, and
communication distribution, the section has continued to perform a significant role in the conceptualization of urban life. With
the rise of populations living in closer proximity and in tighter
quarters, section has become increasingly a means to organize and
control the politics of the city, mapping the complex layers that

A. B. Walker, cartoon in Life magazine, March 1909

are necessary to build and maintain urban systems. As unclaimed
ground is increasingly at a premium, the section of cities becomes
multilayered and contested, providing a ripe site for design projection and invention. From underground transportation and sewers
to military and civilian shelters for survival, the infrastructure of
industrialized cities of the late nineteenth and twentieth centuries
was configured through sectional projection.
The population density that defines the modern metropolis
is made possible only through the most banal forms of the architectural section, yet gives rise to the use of section as a means
to legislate urban politics and map systemic control below- and
above ground. Contemporary urban planning through zoning
(including setback obligations and limits and controls on height)
curbs the unchecked expansion of the city through sectional repetition. Whether through floor-to-area regulations, height restrictions,
or sky-plane exposure analysis, contemporary zoning operates
significantly through the control of section. Zoning controls often
have introduced new imperatives for sectional invention in architecture. The 1916 New York zoning code gave direct rise to the
ziggurat-shaped buildings of the 1930s, where a maximum vertical

Pier Luigi Nervi, UNESCO Headquarters, 1958

height was coupled with an upper-building envelope dictated
by a plane drawn at an angle from the ground to ensure that light
would penetrate to the street. Such edicts resulted in buildings


whose sections were sheared and staggered, stepping back from

the sidewalk to maximize enclosed space. Contemporary rules
specifying that only certain types of spaces must be restricted
according to floor-to-area ratios have led to inventive uses
of section that skillfully deploy mezzanines, voids, and doubleheight spaces to maximize returns on architecture commodified
as investment.
New urban building types increasingly have used sections
as explanatory documents to catalog the multiplicity of systems,
circulation paths, and programs that characterize department
stores, multistage theaters, hotels, and train stations. The sophistication of building technology able to facilitate divergent uses
in a constrained urban block was matched by the increasing use
of section to pack often unrelated parts into a single shell or
volume. These large-scale projects, often public in nature, incorporate the complex technical systems of the city within the space
of a single structure and stand in direct contrast to the standardization of the section characteristic of private development.
Yet at the core, all vertical buildings share a dependence on the
elevator and other robust mechanical systems, without which
multivalent and layered buildings would not be feasible.
The efficiencies of modern construction that have enabled
urban densification have played a central role in the development of se