Air Spaces Changed Everything

Sometimes Materials are Immaterial



This abstract proposes that architectural facade design over the last 60 years has convulsed in light of two disruptions: air spaces which create veneer facades and parametric software, locating any point in space, connecting dots to describe a surface.

Rainscreen principles are now ubiquitous in modern envelopes almost anyplace normal temperatures range beyond natural human comfort. Although all layers of a rain screen assembly contribute to its performance, the critical aesthetic component of this system is the most ephemeral: a zone of air allows the temperature and atmospheric pressure behind the epidermis to match the exterior conditions beyond it.

Parametric software has freed the humble airspace to evolve from the 25mm (1”) wafer in a layering of flat components to a space of any dimension varying from the minimal 25mm to many metres, even undulating within a wall, in service of limitlessly complex geometries. In many cases, these flamboyant forms are attained as ‘blocks’ or ‘chunks’ - as named by Stephen Kieran and James Timberlake in Refabricating Architecture - which are built on a shop floor and assembled on site. The only necessary construction considerations are practical assembly on-site and occasional dismantling.

Now, anything that is not water-soluble or prone to freezing can be a facade.

With no real need to select materials for their intrinsic qualities to create a habitable shell, all the composition rules are gone. Almost anything works. Using stone in a facade is no more about its inherent qualities of compressive strength or imperviousness than a piece of William Morris wallpaper is about the paper - everything is all just durable wallpaper. Is an aluminum panel about aluminum, or a shape or a graphic composition, or hopefully both?

Everything one sees now is a visual material reference to support a design composition treatise – surface materials, in many cases, don’t matter to envelope performance.

As materials suppliers strive for ever-thinner, lighter skin components, the real, technically and materially disciplined envelope is beneath, out of view. Materials do matter behind the form-giving air space, where enormous research investments support marketing of improved energy performance and coping with ever-tougher government standards.

This abstract proposes to discuss how we express/manipulate facades in an era of virtually no material thickness, supported with historic design agendas and historic background going back a century and a half.


Photo of Gerry Lang, M.Arch., (Penn, 2008), B. Arch (hons., Toronto, 1978) OAA, AIA,TSA

Gerry Lang, M.Arch., (Penn, 2008), B. Arch (hons., Toronto, 1978) OAA, AIA,TSA

Senior Associate, Leader of Facades Group

architectsAlliance Toronto



The relationship between architectural composition and the intrinsic qualities of building materials changed irrevocably in Chicago in the nineteenth century and, in purest compositional terms, has been growing more strained

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Early Days, Since 1871

In 1871, the Great Fire destroyed 17,500 buildings[1] in Chicago’s wood-structured business section, precisely when the opening of The West was doubling Chicago’s population every decade (from

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The appearance of mass, once conveyed by deep facades of heavy earthen compression materials, is now a graphic narrative, achieved by lightweight components. It is more a composition of positive/negative

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architectsAlliance (aA), for allowing the use of two project images

SOM New York, for allowing the use of Lever House images

McLennan Jankalns Miller Architects (MJMA), for providing Regent Park Aquatic Centre images

Judith Geher, Architectural Visualisation Artist, Diamond Schmitt Architects, for Photoshop illustrations

Eventscape (Toronto), for providing information on dye-sublimated aluminum

Picco Engineering, for providing information and images of Perry World House stone envelope.

Rights and Permissions

Bergdoll, Barry, and Christensen, Peter. Home Delivery: Fabricating the Modern Dwelling. Museum of Modern Art, New York, 2008

Brock, Linda. Designing the Exterior Wall: An Architectural Guide to the Vertical Envelope. John Wiley & Sons, Hoboken, NJ 2005

Lenzen, Steffi, and Schittich, Christian, editors. Fassaden: Best of Detail. Institut für Architektur-Dokumentation GmbH München, 2015

Kieran, Stephen and Timberlake, James. Refabricating Architecture. McGraw-Hill, New York, 2004

Schons, Mary. “The Chicago Fire of 1871 and The Great Rebuilding.” https://www.nationalgeographic... Geographic Resource Library, January 25, 2011 (accessed June 1, 2019)

Article: Garden, G.K. “Rain Penetration and its Control.” Canadian Building Digest No. 40, April 1963, National Research Council of Canada Archive

Article: Heydar Aliyev Center June 25, 2019)

Article: Sisson, Patrick. “How Air Conditioning Shaped Modern Architecture – and Changed Our Planet.” June 18, 2019)

Article: Hahn, Ashley. “History Grafted onto Contemporary Design at Penn’s New Perry World House” (accessed June 27, 2019)

City of Toronto Fact Sheet, April 27, 2018: 2018 Development Charges By-law Review, p.3

Homepage: NBK Terracotta (accessed June 20, 2019

Image Credits

Figure 1 credit - photo by David K. Staub from Wikipedia.

Figure 2 credit - Photo by Heather Shimin, via Shutterstock.

Figures 3, 20, 21, 22 - Photos by author.

Figures 4, 5 - courtesy of SOM New York

Figure 6 - Canadian Building Digest 40, September 1963

Figures 7,8 - courtesy of Picco Engineering

Figure 9 - Corian website

Figure 10 - NBK Ceramik website

Figures 11, 18 - courtesy of MJMA Toronto

Figure 12 - Photo by Helene Binet, Design Boom, November 2011

Figure 13 - Photo by Helioscribe via Shutterstock.

Figures 14, 19 - Photoshop images by Judith Geher, Architectural Visualisation Specialist

Figure 15 - Longboard Company website

Figure 16 - Photo of Graphic Concrete product, from Altus Group Website.

Figure 17 - Image from Dezeen, Nov. 21, 2018