Crystal Palace Great Exhibition tree 1851 via Wikimedia Commons. Image uploaded by Tldtld.
Sustainable architecture has many shorthands. It can be difficult to unpack terms such as LEED, net-zero, sustainable or green and determine what they really signify to a building practice that, to quote from the Brundtland Commission of the United Nations “…meets the needs of the present without compromising the ability of future generations to meet their own needs.” Aesthetically, architecture in North America and Europe has adopted shorthands for green building as well; one of which is the glassy, layered facade for large-scale institutional and commercial buildings. These buildings, such as offices, housing, and some education buildings, require an even distribution of windows along most of the perimeter to bring daylight to the program spaces. With extensive glazing, louvered screens and daylight sensing shades and lights, these buildings are touted as promoting daylighting while controlling heat gain. They have come to represent state-of-the-art, sustainable buildings.
Yet, we know that only 25-40% of the building skin needs to be glazed in order to achieve good daylighting on the interior, and that an opaque wall can achieve much higher insulating properties than those offered by a glazing system. The architect is largely responsible for the building, which can highly affect the energy performance of the building. My presentation posits the questions: why are we using so much glass for these building types, and what should we be doing instead? The use of extensive glazing is deeply embedded in the architectural profession for various reasons, and only by examining these desires and their effects can alternative paradigms be proposed.
These questions spurred on my Architecture Forum presentation to the office earlier this year. In order to better understand today’s condition, the presentation looked at the history of glass in architecture and what glazing has come to represent both within the profession and the larger public sphere. Layered onto this was an overview of the energy implications of expansive glazing systems at the building skin and the performative values of various wall assemblies and glazing types, including the possibilities of high performing glass facades and the risks of a highly glazed “green” aesthetic that is beyond the economic reach of many projects. With an understanding of the conceptual desires for expansive glass, the energy impacts of its use and the economic realities of its implementation, an incredible opportunity arises for the architecture profession to take a lead in sustainable design by developing new concepts for the building façade that utilize glazing in a more strategic way. The presentation investigated a wide array of façade strategies that represent the beginning of this much-needed paradigm shift, which was followed by a lively discussion with my colleagues.
I will be presenting this research again at this month’s BSA Building Enclosure Council meeting on Monday, October 27, at 4:30 pm. I look forward to discussing this topic further with the audience.