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Recent years have seen a number of announcements of heroic efforts to literally reach for the moon because terra firma is becoming unlivable due to global overheating. Nation after nation has declared its goal of landing on the surface of that celestial orb to colonize new territory, usually suggesting to 3D print dwellings using the surface dirt or sending inflatable pods that expand upon landing to provide shelter. One recent fantastic pronouncement proposed a gigantic solar shield (presumably made of fabric for lightness) that would cast a shadow upon the Earth to help keep annual solar heat gain within acceptable range.
As architects, we have been given a mandate to help mitigate the environmental impact of our buildings and to focus our efforts here on Earth instead, certainly a more practical endeavor.
The architectural profession’s current mantra goes something like this: “Whatever you do, make your buildings reduce their carbon footprint to zero!” This has been the drumbeat for architects since the launch in 2015 by the United Nations of the “2030 Agenda for Sustainable Development” that warns of a no-turning-back-deadline for Earth’s health report.
Architect Nic Goldsmith, FAIA, has made a career of designing fabric structures and doing the heavy lifting with regard to fabric as a material of choice when it comes to sustainability. “This is a big subject,” says Goldsmith, “First there is embodied carbon and then there is operational carbon. Fabric as a material can work for both areas, although in different ways.”
Means to an end
There are many ways to reach the sustainability goal, and this publication will offer several involving architectural fabric as the means. We propose that a) counting the embodied carbon and operational carbon, b) making wise material choices, and c) integrating photovoltaic technologies with fabric structures, can all significantly help reduce the overall carbon impact of our buildings.
Embodied carbon
When it comes to embodied carbon, adaptive reuse of existing buildings is one sustainable approach that has proved highly successful. To start, the lighter mass of architectural fabrics begins the carbon count at much lower levels than more traditional building materials such as wood, steel and concrete. Fabric has a very low embodied carbon measure and also lower carbon footprint for transportation to a construction site. Combining the sequestered embodied carbon of the original building with
the low carbon footprint of fabric elements keeps the overall calculations to a minimum.
There is another approach with reusing existing buildings and that involves modifying existing buildings with “mid-doors” strategies. (See mid-doors sidebar on p. 8 and case study on p. 17.) This approach has been nicely applied by Goldsmith to two public spaces that work with existing buildings to find underused spaces that can be converted to more active use throughout the seasons. The concept of “mid-doors” is relatively recent, and it begins to make use of spaces that are neither indoor nor outdoor but a blend of both, focusing on spaces that provide a protected and pleasurable quality of accommodation.
Operational carbon
Fabric helps keep energy use down with significant shade over our buildings and pedestrian spaces which can generate LEED points. Examples include membrane facades and strategically placed canopies or umbrellas over ground level public walkways (see case study p. 16). The umbrella is a perfect metaphor for what we, as a society, have come to cherish since the impact of the COVID pandemic. We have learned that we can live outdoors more comfortably with protective shades or enclosures, many of which are made with architectural fabrics. In fact, the public has realized that it loves living outdoors, and the restaurants and pop-up food markets, and general gathering spaces produced by the pandemic have kept many of these organizations in business by the use of fabric shelters (see case study p. 15).
Careful material selection
Material choices can have an enormous impact on an architect’s attempt to be energy efficient and wise when specifying products. Key to this is the increasing use of Environmental Product Declarations (EPD) to help verify “truth in advertising” when buildings must perform as efficiently as possible. The commissioning of building systems (such as heat pumps), the operational performance standards and client requirements that squeeze the most energy out of the embodied material carbon footprint, as well as insulation specifications, have necessitated the use of third-party verifications such as EPD. Thus EPD becomes the standard to match and has quickly become de rigueur for carbon counting.
Moreover, architects have a prime responsibility to reduce the environmental impact of their buildings and, as frequently quoted in building energy performance reviews, 40% of all carbon impact in the world can be attributed to buildings, their operations, their materials and performances, and life-cycle energy usage.
When it comes to North American membrane structure design and construction, several recent changes have occurred to the fabrics supply chain. “Evolutions in materials abound,” says Craig Huntington, SE, F.ASCE of Huntington Design Associates, Oakland, Calif., “and most prominent among these has been the emergence of membranes made from foil materials, chiefly ETFE. Where conventional fabrics have been limited to light transmissions of 15% or so, ETFE material provides near transparency.”
A common application of foil materials involves wrapping existing structures with sophisticated facade systems to help reduce solar heat gain. “Membrane facades are an area of market growth and design innovation for both new and retrofitted construction,” says Huntington. “Typically, membrane facades are employed as light-transmitting shading devices and
facade visual enhancements for office buildings and other applications.”
One of the more handsome examples of this type of application is the University of Cincinnati Gardner Neuroscience Institute by Perkins & Will, Minneapolis, Minn., with facade designed and installed by Structurflex. A large number of these retrofits are for parking garages, and that makes sense in response to city ordinances that require screening of most garages. The durable mesh fabrics used for facade treatment also readily accept graphic design elements in a variety of colors.
PV in your future?
Integrating photovoltaic (PV) features has become one of the strong cards to play when calculating the carbon bottom line. The development and rapid improvement in energy efficiencies for the “thin film” version of PV is offering architects a new opportunity to reduce material weight and add back to the energy balance calculations. Just as ETFE has become one of designers’ favorite new materials, thin film PV could become the next bright tool in cracking the metrics of reaching zero emissions.
A 2023 feature story in Specialty Fabrics Review, reporting on the progress of solar-powered fabrics, stated that new, more efficient versions of PV crystal (used to convert light into electrical pulses) that bond with fabrics “could be available within the next decade for use on marine, tent and awning canvases, as well as conventional buildings (see case study p. 14). Although adding PV components is only one tool in a host of sustainable tools we get to use, not everyone feels at ease with putting panels of PV on their building. Yet, it can contribute to one of the AIA’s Framework for Design Excellence, under the category of “Design for energy.” Thin film PV answers the framework’s question: “How can the project exceed building code efficiency standard to approach net zero energy and net zero carbon?”
With these methods described here, of integrating fabric elements into your buildings, we hope you find it useful as well as practical to improving your building design and performance throughout the value chain of construction.ϖ
Bruce N. Wright, FAIA, the former editor of Fabric Architecture, teaches architecture and construction management at Dunwoody College of Technology and is a consultant to architects and designers. He is a frequent contributor to Specialty Fabrics Review and Textile Technology Source.
Resources
Birdair Inc. birdair.com
Huntington Design huntingtondesign.com
NovaShield itape.com
Nowofol (ETFE) nowofol.com
Pvilion pvilion.com
Serge Ferarri sergeferrari.com/us-en
Sonoma Shade Sails sonomashadesails.com
SunCraft NZ suncraft.co.nz
TYLin Lightweight Structures Group tylin.com/lightweight-structures-group
SIDEBAR: What is “mid-doors”?
In November 2020, well after the beginning of the COVID-19 pandemic, the business journal Fast Company ran an article by Erik Olsen that defined “mid-doors” as a transition zone between inside and outside. “Rather than thinking of indoors and outdoors as a binary condition, we need to acknowledge there is a spectrum from indoors to outdoors,” Olsen wrote.
He cited several familiar places—large atriums amid big office buildings, grand European train stations that provide protection from sun and rain but are mostly unheated, and covered markets that only shade or stop the rain. He stated that “mid-doors spaces provide energy savings. Relaxed temperatures result in less heating and cooling energy, or in some cases, no energy at all.”
This Specifier’s Guide features two projects that were designed as mid-doors spaces, both located adjacent to Times Square in New York City. The TSX project designed by Perkins Eastman Architects and Silman, features ETFE pillow roofing and ETFE motorized walls (see p. 5).
“These allow for indoor/outdoor spatial qualities,” says Nic Goldsmith of Silman, “as the exterior temperature changes. This was an outdoor terrace which could now be utilized for year-round use. The mechanized retractable ETFE sidewalls are the first application of this material as a retractable glazing system.”