Performance Based Envelopes

Performance Based Envelopes: A Theory of Spatialized Skins and the Emergence of the Integrated Design Professional

Franca Trubiano

Architecture Program, PennDesign, University of Pennsylvania, Philadelphia, PA 19106, USA

Figure 1. London City Hall—Foster and Associates (Courtesy Terri Boake, University of Waterloo).

Realigning the design of building envelopes within the measures of air, light and heat has rendered possible an inventive form of practice whose benefits are far in excess of the metrics of data and analysis.

For many of its most advanced practitioners, the contemporary design of facades engages the true potential of “performance” when it deepens, broadens and complicates the theoretical dimension of this most liminal of surfaces.

Figure 2. Linked Hybrid—Steven Holl (Courtesy Terri Boake, University of Waterloo).

Of particular interest to this paper is a discussion of new theoretical paradigms associated with the design and operation of high performance envelopes of which four characteristics of this emergent sub-discipline are herein examined.

To begin with, the way in which building envelopes are no longer separators, dividers and barriers between a building’s interior and exterior conditions, but rather, “spatially” defined environments that fully engage the totality of a building’s engineering systems, is discussed.

Figure 3. Water Cube Project in Beijing, China, ARUP Associates (Courtesy Terri Boake, University of Waterloo).

Cantilevered Louvers, Double Skin Facades and Hybrid Conditioned Atria are representative of this new paradigm as is the use of Responsive Technologies to optimize their behaviors.

Lastly, the paper examines the rise of the new integrated design building envelope professional called upon to deliver ever-better performing skins, whether in the guise of energy modeler, climate engineer or façade construction specialist.

Hence, this paper develops a theoretical structure within which to describe, analyze and interpret the values made possible by this new and expanding field of performance based envelopes.

Figure 4. Lincoln Square Synagogue (Courtesy Front, NY).

Much of the current discourse on energy efficiency and architectural design has coalesced around the subject of building skins.

As highly technological devices, these works of architectural engineering are predicated on data based performance benchmarks, virtual simulations, and the laws of computational fluid dynamics.

Figure 5. Lycée Albert Camus, Foster + Partners, Reprinted with Permission from © Dennis Gilbert/VIEW.

Increasingly, they are responsible for the conservation of energy, the maintenance of thermal comfort, and the optimization of daylight and fresh air distribution, and as such designed, constructed and operated to meet ever more prescriptive goals.

Figure 6. Transsolar Double Skin Façade—Sparkasse Rosenheim, Reprinted with Permission from © Transsolar.

For many, refocusing the functionality of building envelopes on environmental metrics offers precisely the needed, vastly more objective terrain within which to evaluate their role as facades.

For others, it only privileges the technological determinism of building physics at the exclusion of all other design considerations.

Figure 8. Swiss Re Tower, London, England—Foster and Associates (Courtesy Terri Boake, University of Waterloo).

What is clear, however, is that the vast quantity of information and data generated, simulated, collected, analyzed and associated with the energy loses and gains of building skins increases exponentially every year.

A plethora of numbers and figures is now available to designers and engineers. For the large number of professionals whose clients continue to demand architectural envelopes constructed and operated to meet net zero goals, avoiding the use of data is not an option.

Figure 9. Swiss Re Tower—Interior Atrium (Courtesy Nigel Young/Foster + Partners).

Contemporary envelopes, when designed using performance based metrics attendant to air, light and heat give rise to an inventive form of practice, which albeit involves the processing of vast amounts of data, also registers benefits far in excess of said data.

Figure 10. Manitoba Hydro by Transsolar—Systems Diagram by Brian Christie Design.

In fact, engineering highly responsive facades secures a heightened definition of “performance” when engaging the more speculative dimension of building skins.

When novel design ideas are captured and represented across this most liminal of surfaces, the every way in which we think about building envelopes is fundamentally challenged. What emerges is an alternative paradigm for a theory of building.

No longer are envelopes conceived as dematerialized barriers between a building’s interior and exterior conditions, but rather as spatially determined environments fully engaged in the totality of a building’s engineering systems.

Figure 11. Manitoba Hydro Place, Double Skin Façade (Courtesy Terri Boake, University of Waterloo).

With the goal of significant reductions in energy use, design techniques, both old and new, are being developed and implemented to maximize environmental gains such as improved air and water quality, material reuse and recycling, resourceful site management, and reduced carbon emissions, amongst others. They also contribute much needed value to the figural language of architecture.

Figure 14. Al Bahar Towers, Abu Dhabi—Aedes (Courtesy Terri Boake, University of Waterloo).

Four such techniques are discussed and illustrated in this paper of which the propensity to increase the “depth” of the envelope is common to all.

Whether by the projection of exterior planes; the multiplication of material layers for moving and exchanging air, light, and heat at the exterior surface of the building; the introduction of program based architectural volumes that replace a building’s mechanical systems; or the introduction of responsive electronics, the sum of these technological imperatives is the material, dimensional, tectonic, and digital “spatialization” of the skin.

In deepening the section of the skin, each of these four techniques have reconfigured the performance mandate of building envelopes and in so doing have changed the very nature of how buildings appear.