090715 Princeton_Alejandro Zaera Polo_ Board 1

Page 1

Flat-Vertical

Princeton Envelope Group (PEG): Envelope Categories

The category of the flat-vertical envelope, better known as a slab, (x<y=z) includes those envelopes whose predominant dimensions are parallel to gravity and distributed along a line. Flat-vertical envelopes are generated by the horizontal displacement of a section of space, which, in order to support a specific function, optimizes density, daylight, ventilation, structural constraints, and the building’s relationship with public space and infastructure. Land uses and orientation are crucial drivers for this envelope type. Most mid-rise residential and many office buildings are probably in this category, as they respond to the need to host a large volume of homogenous program. The flat-vertical envelope is primarily determined by the facade-to-facade or facade-to-core depth, hence its laminar organization. Modern urban fabrics are predominantly matrices of flat-vertical envelopes combined in various configurations suited to a particular climate, use, and culture. The flat-vertical envelope usually has a high level of enviornmental performance and a relatively low level of expressive performance.

The building envelope is possibly the oldest and most primitive architectural element. It materializes the separation of the inside and outside, natural and artificial; it demarcates private property, land ownership and social exclusion; when it becomes a façade, the envelope operates also as a representational device, in addition to its crucial environmental and territorial roles. The building envelope forms the border, the frontier, the edge, the enclosure and the joint: it is loaded with political content. At a time when energy and security concerns have replaced an earlier focus on circulation and flow as the contents of architectural expression, the building envelope becomes a key political subject There is no such a thing as a unitary theory of the building envelope in the history of architecture. Previous embodiments of envelope’s theory have addressed either representation or construction technologies. The traditional split between wall and roof construction has prevented the discipline to look at the envelope in a more holistic way, as a single object of analysis. The Princeton Envelope Group aims to develop a general theory of the contemporary building envelope. The research will be tested through symposia and publications, and finally collected in a Manual of the Building Envelope. The Princeton Envelope Group produces concrete architectural proposals with a prototypical format, testing them in concrete scenarios. The research is aimed to produce a series of prototypes to explore the global aspects of the envelope design, and has been structured in 4 different envelope groups, characterized by their aspect ratios: flat-horizontal, spherical, flat-vertical and vertical. The work aims to a prototypical output format. The projects we have identified to be developed in this first edition of the Princeton Envelope Group have been: - Atlas for Sustainable Mixed-Use High-rise Floorplates - Prototype for the American Embassy of the Future. - Manual for the Sustainable Walmart - Catalogue of High-density Residential in Hot-Humid Climates

Vertical footprint

1.0

Taipei 101

Commerzbank

Petronas Towers

Lippo Tower

Chicago Spire

Torre Agbar

Marina City

Aqua Tower

Silver Towers

860 880 Lakeshore Drive

Circle

0.8

Square

Facade RaƟo

Triangle

7m

The vertical envelope has a predominantly vertical dimension and, unlike the flat-vertical (x=y=z) type, a multidimensional orientaiton in plan. The specificity of this envelope category is an intense relationship between physical determination and performances. Because of its scale and technical complexity, functional and enviornmental performances such as daylight penetration and natural ventiliation need to be maximized, while the formal qualities of the envelope play a crucial role in the building’s structural stability. The vertical envelope’s geometric determiniation crucially impacts both the spaces that it encloses and its surroundings. In addition, the visibility of the vertical envelope makes its particularly conducive to iconographic performance. If in the spherical envelope the gap between representative and enviornmental performances reaches a maximum, in the vertical envelope both sets of performances are at their highest level. The collusion between extreme technical performance and high visual impact produces the maximum tension between efficiency and expression, a condition that runs deep in the history of this building type.

1.2

occupiable floorplate

17.6 m

20

m

16 m

12.7 m

16 m

14.6 m

0.6

Cross (1/3, 1/3, 1/3)

Silver Towers

Cross (2/5, 1/5, 2/5)

8m

11.2 m

10.3 m

Rectangle (1:5)

Y Tower

860 880 Lakeshore Drive Torre Agbar 0.4

Star

Petronas Towers

Rectangle (1:10)

Commerzbank

Lippo Tower

džŝƐƟŶŐ dŽǁĞƌƐ

Aqua Tower Marina City

core to perimeter: 20.0 m

core to perimeter: 17.6 m

core to perimeter: 16.0 m

core to perimeter: 14.6 m

core to perimeter: 16.0 m

core to perimeter: 12.7 m

core to perimeter: 10.3 m

core to perimeter: 11.2 m

core to perimeter: 8.0 m

core to perimeter: 7.0 m

Chicago Spire

Taipei 101

0.2

naturally lit floorplate

0.0 0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Tower Footprint Area (m2)

floor area : 2160 m² w.o. access to daylight: 787 m²

floor area : 3321 m² w.o. access to daylight: 2683 m²

floor area : 2047 m² w.o. access to daylight: 782 m²

floor area : 1515 m² w.o. access to daylight: 640 m²

floor area : 1120 m² w.o. access to daylight: 482 m²

floor area : 2628 m² w.o. access to daylight: 425 m²

floor area : 1140 m² w.o. access to daylight: 320 m²

floor area : 1762 m² w.o. access to daylight: 480 m²

floor area : 726 m² w.o. access to daylight: 72 m²

The above graph shows the relationship between floorplate area and facade ratio for towers with different footprint shapes. All the curves assume a 3.3 meter floor to floor height typical in residential tower construction. The points represent existing towers showing how real life cases

floor area : 640 m² w.o. access to daylight: 114 m²

correspond to the idealized model. The circle is the tower footprint with the smallest facade area per unit area of interior. As shapes become more elongated or corrugated the facade ratio per unit area of interior increases.

Spherical The spherical envelope’s dimensions are approximately equivalent in all directions; cubic, spheroidal, and polygonal geometries are also (x=y=z) particular cases in this category. In principle, the spherical envelope has the lowest ratio between its surface and volume it contains. The specificity of this type is the relative independence that the skin acquires in relation to its programmatic determinations, as functions are not strongly determined by adjancency to the outside and, therefore, by the form of the envelope. This often implies a wider variety of programs inside and a hetrogeneous enviornmental content. Sperhical envelopes generally enclose a wide range of spatial types with specific functions, rather than a single spatial condition. Unlike other envelope types in which the border between public and private occurs on the surface of the container, the spherical type often contains gradients of publicness. Spherical envelopes often correspond to public buildings that gather a multiplicity of spaces, such as city halls, courthouses, libraries, museums, and arenas. In the spherical envelope the gap between expressive and enviornmental performances is at a maximum, with low enviornmental and high expressive performances.

Aldo van Eyck Orphanage Double House

Farnsworth

SA / V (m2/m3)

Toledo Glass Museum Taipei 101 MASP

Westin Peachtree

Free University Mpreis McCormick Campus Center

Nexus Housing

Aplix

Torre Agbar Centraal Beheer Office Building

Casa da Musica Villa VPRO

Laban

London City Hall shows the three different types of spherical buildings as The above diagram Aqua Tower Gifu Housing Unite determined by the previous graph. Examples of each type are shown below. Silodam

Stansted Airport Jeddah Golden Resources

Baker House

Pentagon

Tokyo Opera House

Mall of America

Water Cube Mies Convention

The graph above establishes the definition of the spherical building type. The red line shows the surface area to volume ratio of a perfect geometric sphere. The black line shows the surface area to volume ratio of a perfect cube. The dotted black line shows the empirically determined variability in the type while still being close enough to the ideals to be considered spherical.

The gray shaded region is the area of the graph that is considered spherical. No geometric shape can have a smaller surface area to volume ratio than a perfect sphere so the gray region never goes above the red line. Deviations from the ideals beyond a certain threshold cannot still be considered spherical and therefore the dotted line bounds the bottom of the gray region.

Buildings are plotted as points indicating their surface area to volume ratio. Buildings that fall within the gray region are considered spherical and shown as black dots. Buildings of the tower type are shown as red dots, flat horizontal buildings are shown in green, and flat vertical buildings are shown in blue.

The zoomed out graph on the left shows that spherical buildings don't get as large as flat horizontal or flat vertical buildings. Also the largest buildings on the graph, the Mall of America and Mies' Chicago Convention center have relatively large surface areas for their enclosed volumes.

This graph defines the three different scales for spherical buildings. The ideal cube and sphere are plotted as in the previous definition graphs but here the surface area to volume ratio is plotted relative to the rough diameter of the building. When the diameter of a building is small the surface area to volume ratio increases and when the diameter is large the surface area to volume ratio

Wal - Mart #1800

Glass Box

Flat-Horizontal

decreases. This can be understood by inspecting the equations for the volume and surface area of a sphere. Because of this change in surface area to volume ratio based on building scale a program to scale correspondence exists. The two scale thresholds are indicated by vertical dotted lines.

Residential Sphere

Big Box

Corrugated Box

Mat Building

Mothership

0.6

Mat Building (proliferation of courtyards, general edge irregularity; i.e. Van Eyck’s orphanage) Mother Ship (monolithic figures; i.e. Mies’ Convention Center, Water Cube, Jin Yuan Mall) Donut (single, large, central courtyard; i.e. Pentagon, Jeddah)

Jin Yuan Mall

Mall of America

The Pentagon

Early figures produced by examing SA/V ratios in relation to P/(2X+2Y), our method for calculating invagination, seem to bear out this thesis. It is, however, not the identification of evolutionary stages that interests us but rather in that of its gaps and overlaps and the limits of the FH type, for identifying these areas will provide opportunities for more focused inquiry as to their origins, be they programmatic, economic, social, etc.

Mothership

Mat Building

Donut

Aldo van Eyck Orphanage Aldo van Eyck Orphanage

0.5

Double House

Broken Box (small courtyards begin to appear, corrugation of edges occurs; i.e. Aplix Factory)

FBU

Tokyo Opera House, Jean Nouvel

0.6

0.5

Big Box (featurless facade, some skylighting, i.e. Wal-Mart) Aplix

Program Detached from Envelope

Casa Da Musica, OMA

Donut

Flat Horizontal building types from small to large: Glass Box (prismatic form, large expanses of facade glass, impermeable roof; i.e. Farnsworth House)

Civic Sphere

Double House, MVRDV

Corrugated Box Big Box Glass Box

Wal - Mart #1620

Laban Centre

MAAB

The category of flat-horizontal envelopes includes those in which the horizontal dimensions are considerably larger than the (x=y>z) vertical. Buildings like airports, train stations, factories, trade fairs, convention centers, markets, and retail and leisure complexes generally belong to this category. The political performance of flat-horizontal envelopes lies in the delimitation of edges, frontiers, and boundries, and in the sheltering of large-scale atmospheres operating primarily through the articulation between natural and artificial. Since a comprehensive perception can only be obtained from an aerial perspective, flat-horizontal envelopes are experienced in a fragmented manner are, therefore, less concerened with representation and figural performance than with the organization of material flows: traffic, ventilation, daylight, security, etc. The flat-horizontal envelope usually presents relatively low affective and environmental performances.

21st Century Museum

Double House

0.4

0.4 Farnsworth

Farnsworth

SA / V (m2/m3)

21st Century Museum

21st Century Museum

SA / V (m2/m3)

0.3

0.3

Toledo Glass Museum

Toledo Glass Museum

Taipei 101

Baker House

MASP

Westin Peachtree

MASP Gifu Housing

Free University

0.2

McCormick Campus Center

London City Hall Silodam

Villa VPRO

Aplix

Centraal Beheer Office Building Casa da Musica

Centraal Beheer Office Building

Casa da Musica

Gifu Housing

Mpreis Nexus Housing Silodam McCormick Campus Center

Aplix

Torre Agbar

0.1

Free University

0.2

Mpreis Nexus Housing

London City Hall Villa VPRO Laban

Laban

Aqua Tower Unite

Stansted Airport Jeddah

0.1

Westin Peachtree Torre Agbar Aqua Tower Unite

Golden Resources

Baker House

Pentagon

Taipei 101

Pentagon

Tokyo Opera House

Tokyo Opera House

Golden Resources Mall of America

Water Cube Mies Convention

Mall of America

Water Cube

Stansted Airport

Mies Convention

0

0 139

1555

1800

2603

3180

3650

4235

4290

7549

9278

9308

30000

32045

35000

35344

48400

56000

176000

197449

1102500

0

50000

100000

Footprint (m2)

Flat Horizontal

Flat Vertical

Vertical

150000

200000

Footprint (m2)

Sphere

Flat Horizontal

Flat Vertical

Vertical

Sphere

250000


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