Crticism of Sustainably Designed Buildings
Sustainable Building Materials and Technologies under Microscope
Oct 5, 2009
Shari Shapiro has coined the word “greenbashing” to describe spurious criticism of sustainably designed products and buildings. Some of this greenbashing is unwarranted, as Shapiro demonstrates in a blog entry for August 2009.
Shapiro highlights three egregious examples of greenbashing. One of these features an executive director of a provincial roofing contractors association. He suggested green roofs were more combustible than regular roofs, a statement that does not stand up to scrutiny.
Critics of sustainable building also attack LEED for either not being forceful enough, or conversely, for setting the bar too high. Many of these commentators have not actually studied LEED; they are noisy without being well versed in the certification system and its inner logic.
Some of the most serious reservations about green building come from engineers at Building Science Corporation. Jeff Melvin and his associates often ask probing questions that deserve consideration.
Engineering Assessment of Sustainable Design
Building Science Corporation is an architecture and building science consulting firm with offices in Boston, Massachusetts and Waterloo, Ontario. The firm has built its reputation on building technology consulting, with a focus on moisture management, indoor air quality and understanding why buildings fail to perform as expected.
In recent issues, the firm’s newsletter has covered exposés of questionable sustainable design practices. Included in these are double façades, or buildings with two layers of glazing with an air plenum between the two layers.
The design intent of a double façade is that the air between the glazing layers is either captured to warm the building in winter, or circulated to avoid overheating the building in a hot climate. Double-skinned edifices are supposed to be more energy efficient than conventionally-glazed buildings with a single layer of glazing.
Not all double facades perform well. In worst case scenarios, they have been shown to use more energy than conventional commercial architecture.
Interstitial floors, and distribution of mechanical systems through underfloor air plenums, have also been analyzed. Interstitial service floors promote design flexibility by allowing work spaces to be easily reconfigured as technology and services change. Underfloor distribution of mechanical services simplifies the provision of occupant-controlled thermal and ventilation systems so valued in LEED buildings.
The experts at Building Science Corporation have posed tough questions about how these floor systems, especially more shallow spaces filled with the spaghetti of wiring for technology, will be cleaned to avoid the growth of dangerous moulds.
Experiments in Sustainable Building
It is inevitable that as new technologies come onto the market to meet the demand for green buildings, not all will perform equally. Stalling on the adoption of sustainable technologies, because some building systems have been poorly conceived or constructed, is a lame way to encourage sustainable building practices.
The best sustainable buildings are realized through an integrated design process that brings everyone to the table: engineers, building science experts, architects and other designers, as well as the building’s users and owners. It is a process that if informed by good science can only improve how architecture is erected.
Sound building science principles can guide more effective application of new technology and improve existing practices. This is where those pernickety engineers and their questions come in handy, encouraging the best design and construction possible.
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