The Council on Tall Buildings and Urban Habitat has released a series of video presentations from their 9th World Congress, held September 19-21, 2012 in Shanghai, China. The sold-out, three-day event brought together over 800 of the world’s leading tall building owners, developers, contractors, architects, engineers, planners, and policy-makers to discuss the “Age of the Sustainable Skyscraper City.”
Among the included presentors is Mic Patterson, Vice President & Director of Strategic Development for Enclos, who lectured on retrofit and lifecycle considerations for the building Facade. Patterson’s New Skins for Skyscrapers: Anticipating Facade Retrofit delves into the high-rise boom of the 1960’s as the precursor to many of today’s aging, underperforming buildings. His lecture discusses in length the opportunity for retrofit in existing buildings through a series of case studies, including the recent reclad of the Jacob K. Javits Convention Center in New York City, one of the largest applications of space frame technology in the world.
Patterson’s CTBUH conference video is available in its entirety here.
“Facade Futures” first appeared in the Facade Tectonics Journal, the University of Southern California School of Architecture’s focus group publication, in 2011. The Advanced Technology Studio of Enclos now publishes a revised outlook annually. The intent is to identify continuing and emerging trends by looking back upon the events of the previous year and anticipating what the New Year will bring. The following is adapted from the original journal article and addresses many of the same topics. We welcome your comments.
by Mic Patterson
Until the recent shift toward the modular, prefabricated curtainwall designs referred to as unitized systems, not much has changed in contemporary curtainwall technology since its advent in the mid-twentieth century. Not since the early pioneering days of lightweight, thin, aluminum and glass systems replacing traditional masonry infill walls has the facade industry been so challenged to innovate. Market forces including escalating performance demands are driving a step change in building skin technology, bringing increased attention to the facade and interest across professional, industry and the academic boundaries. Rapid climate change, volatile energy prices, depletion of easily accessible carbon-based energy resources, unstable economic conditions, increasing adoption of green and sustainable building practices, and urban population growth are all among the pressures forcing change across broadening areas of global culture. The intent here is to take a brief look at how these forces are shaping the future of the built environment through the building facade.
General Market Conditions (a contextual sketch): Economic conditions have improved in 2012 with a progression of mildly favorable indicators. The ABI (Architectural Billing Index), was up in November for the 4th straight month. Its gains are being led by the residential and industrial sectors, the while institutional and mixed-use markets are actually down. Nonetheless, many industry professionals we’ve talked with are guardedly optimistic in 2013. The emerging market conditions are not uniform across the nation, with some regions booming while others languish. Tall building construction has resumed with a vengeance in New York City, with over twenty towers currently underway (Curbed). While new office building projects have certainly come to life, the emphasis remains on luxury residential and mixed-use projects with a significant residential program. San Francisco is also in the midst of a resurgence of building activity (read more). All sectors have contributed to the uptick, as owners and developers pull the trigger on delayed projects in anticipation of rising costs resulting from improved market conditions. In fact, leading facade contractors are busy with growing backlogs and recruitment activities to fill open operations. Look for the improving conditions to gradually spread to other large metropolitan areas that have yet to benefit, and for a leveling off and possible gradual downturn in the current hot markets. Much, however, will depend upon emerging developments in the overall marketplace through 2013’s first quarter. The underlying market conditions are felt by many to lack fundamental stability, and any number of emerging variables could negatively impact market direction. International concerns include the dire economic conditions in Europe and continued political unrest in the Middle East. Looming issues at home include the lingering effects of the subprime mortgage crisis, the perceived “fiscal cliff,” the expiration of the Bush tax and payroll cuts, another debt ceiling showdown, student debt, continuing tight credit, and so on. Good fortune may smile upon us, but be prepared for market turmoil in 2013 — the potential is certainly there.
The Push & the Pull: The architectural facade has long been a compelling focus of interest for building scientists and designers alike, combining attributes of both appearance and performance in a manner unlike any other building system. It is informative to study the patterns of innovation within markets, the relationship between the push of industry vendors and material suppliers, and the pull of design teams demanding superior materials, products and services. The construction marketplace has been dominated for decades by the push, with newly available products and technologies often slowly adopted by building design teams. The traditional practice of masonry infill walls in the early half of the twentieth century continued for decades even after new structural framing practices and lightweight building materials made novel approaches possible. This dynamic has undergone a fundamental shift: the long-running dominant industry push has been supplanted by a waxing pull from the design team for better performing materials. The manifestation of this dynamic is increasing innovation in facade design and all aspects of facade technology.
Its Still (almost) All About Glass: Glass remains a ubiquitous material in the building skin, a virtual commodity material, in spite of the challenge it poses in extreme loading conditions (blast and impact), and its extensively documented behavior as a poor thermal and acoustical insulator. Despite frequent predictions of a decline in the use of glass in the building facade, the trajectory remains upward, as evidenced by the latest crop of glass skyscrapers taking shape from in New York City and throughout Asia. Meanwhile, the debate continues: should the use of glass be prescriptively limited, or are large areas of glass required to maximize energy efficiency? Daylighting is a determining factor here, and substantial documentation exists demonstrating that large areas of clear glass are not a prerequisite for effective daylighting. There is also the argument that large areas of glass actually create more challenge than benefit with respect to good daylighting design (Daylighting Collaborative). Nonetheless, the extensive use of glass will persist, driven not by performance issues but by the owner and occupant demand for the aesthetic of floor-to-ceiling glass. Developers have learned that they can demand higher lease rates and enjoy higher occupancy rates with buildings featuring an extensive use of glass. This will not abate without legislative intervention in the form of significantly escalated requirements for the energy performance of buildings, including daylighting analysis and energy modeling for any large building. This is coming, but only gradually. The voluntary adoption of green codes, standards and rating systems could speed the process, but much will depend upon economic conditions. Meanwhile, material suppliers continue to develop architectural glass products with ever-improving performance attributes.
Security Glazing & Facades: Safety concerns continue to rise after the Oklahoma City bombing and devastation caused by Hurricane Andrew in the 1990’s. As terrorist and storm threats continue to increase, so will the development and application of security glazings and facade designs. Blast design criteria are now commonplace on government and many public buildings. Given the recent devastation caused by Hurricane Irene and Sandy, look for impact-resistant provisions found in South Florida building code to migrate northward.
Dynamic Glass: The market penetration of high-performance electrochromic products appears to be imminent. Sage Electrochromics was acquired by Saint-Gobain, potentially bringing massive resources to the SageGlass product line (read more). Soladigm has raised significant amounts of private equity funding and has partnered with Guardian to bring their electrochromic product to market (read more). Both are in the process of bringing new high capacity fabrication plants on-line with the promise of competitive products for building facade applications.
Thin Skins: Architectural glass is a highly engineered material with a tremendous amount of technology packed into an extremely thin panel —the typical double-glazed IGU is only 1 inch deep (25 mm). Solar, thermal and acoustical performance continues to rise through methods of triple glazing (two cavities), cavity treatments (thin-films, aerogels, gas fill, fritting and mechanical sun control devices), and an increasingly diverse range of interlayer laminating materials. Look for triple-glazing to gradually increase market share as a relatively easy and effective green building design strategy, especially in comparison to the cost and complexity of double-skin facade solutions. Vacuum glazing holds future promise as an affordable high-performance thermal material that, interestingly, produces a panel of even less depth by reducing cavity thickness (read more).
Deep Skins: Conversely, facade designs are getting deeper with the introduction of multiple skins, deeper cavities, shading systems, and maintenance and circulation space within the cavity. A new Gensler designed Shanghai Tower under construction in Pudong includes a double skin that incorporates multiple atria within the cavity (read more). The profession is equal parts interested in and skeptical of double-skin facades. The continued upward trend of this technology is threatened by lingering negative economic conditions, but the facade is no longer constrained to the thickness of a conventional curtainwall system.
Shape Shifting: Geometric complexity in the building facade will continue while fueled by new parametric modeling tools such as Rhinoceros and Grasshopper (and the rest of the zoo), all of which are eagerly embraced by students and young professionals. Optimization is an emergent computation process providing the rationalization of complex surfaces as a means to reduce component differentiation in the built facade.
Daylighting: Daylighting requirements should be legislated as a means to reduce electricity consumption, a major contributor to GHG emissions. While appropriate leadership to accomplish this is lacking, daylighting design practice is gradually growing. The U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) program, despite its shortcomings, encourages this practice. Daylighting also contributes to a healthier work environment, but requires good design practice to avoid problems with glare.
Integrated Facades: In the deeper zone of the building envelope (see Deep Skins above), shade systems and electric lighting will be tied to the facade through sensors and controllers, with the whole system tied to a building automation system. These systems are growing in effectiveness and becoming more affordable. For a great example, see the work done by the Lawrence Berkley National Laboratory on the New York Times Tower (read more). Building systems integration is a fundamental aspect of high-performance building design.
Acoustical Facades: Acoustical behavior has emerged as an issue of growing concern, largely driven by the increasing urban residential population. The inside/outside sound transmission properties of various glass products are well known and documented, but it gets more complicated with a curtainwall system. Flanking sound, or sound across partitions, floors and building units, is emerging as a significant problem. Triple glazing, laminating, and double-skin facades are all techniques to improve acoustics through the building skin.
Facade Retrofit: The facade retrofit of older buildings with contemporary facade technology is gradually gaining momentum, especially in key market sectors like New York City. The city added a regulation allowing for the expansion of the building envelope by eight inches to accommodate over-cladding retrofit strategies. The retrofit of the Javits Convention Center in New York City is just now nearing completion (read more).
Glare: As with acoustics, glare has emerged as a significant problem with glass, both inside and outside the building envelope. The marketplace has seen its first lawsuits dealing with glare, including the highly publicized occurance at the Vdara Hotel & Spa in Las Vegas and the Nasher Museum in Dallas (read more). Glare problems in China have caused code changes and prompted regulating authorities to block the construction of some new glass skyscrapers.
Building Integrated Photovoltaics (BIPV): The commitment to renewable energy sources remains low, hobbling what should be a robust market that would both provide jobs and reduce environmental stress. The technology continues to improve, but while cost is gradually dropping it remains high. New projects incorporating BIPV continue to emerge, but the BIPV component is frequently value engineered out, limiting it application to a small projects in even smaller markets.
Durability: This aspect of performance is often ignored in the high-performance building facade dialog. Predicted service life does not equate to warranty period, at least not inherently. Most materials and products are actually warranted for a far shorter period than their expected service life, but this service life often goes undefined. The issue of durability is starting to make its way into the dialog in the form of standards and rating systems. The Canadian version of LEED includes a point for durability planning, although nothing in the United States has emerged so far (read more).
Lifecycle Assessment (LCA): It’s just not all about energy consumed during the operations phase of a building. Embodied energy and environmental impacts must also be considered. Lifecycle is gradually emerging as the appropriate timeframe for evaluating cost, environmental impact and additional sustainability factors. LCA is the framework for evaluating the full spectrum of relevant building performance considerations. Lifecycle costing (LCC) will not soon replace first-cost and short-term payback analysis as the metrics of private developers, but ultimately, mandatory requirements will force the issue. LEED Version 4 introduces the topic into the dialog with a point involving building LCA (read more).
R&D: The construction industry has long been negligent in reinvesting profits in new research and development. This is changing as suppliers, vendors and contractors recognize that their success in a more competitive and technically demanding future will depend increasingly on their ability to deliver more efficient and economical solutions. Despite the prospect of continuing tight economic conditions, R&D spending must increase. There is great opportunity for collaborative R&D initiatives bringing together government, industry, academic and professional groups in common pursuits. This needs to happen.
Post-Occupancy Monitoring: Many are rightly and righteously frustrated by the lack of performance data yielding from the many high-performance buildings that have become operational in recent years. There is no excuse for this, but there are many reasons. Sometimes the data is simply not collected. In other cases data is collected but not shared for liability reasons. New York City has instituted an energy reporting requirement that is just producing its first round of data, and raising some eyebrows in the process (read more). Look for this program to pressure further code changes and spread to additional cities. Building rating systems like LEED will increasingly adopt post-occupancy monitoring requirements.
LEED: Midyear 2013 should see the release of LEED Version 4. The schedule 2012 release of the upgraded system was postponed to allow for a fifth public comment period ending December 2012. Adverse economic conditions have impacted certification growth, but use of the building rating system continues to spread both internationally and domestically. Future growth will depend upon developments in national economies and the adoption of the voluntary system by institutions, governments and private developers.
Trends are indicators, not predictors, and can shift rapidly under the pressure of prevalent market conditions. This is why they are important to watch as a means to anticipate both opportunity and threat. There remains underlying instability in the marketplace, which will likely produce some market turmoil in 2013 with the ability to manifest in unpredictable ways, especially if negative economic conditions reemerge. Future success will be a measure of actions taken now in preparation for these coming changes.
About the Author:
The John Jay College of Criminal Justice is a 2012 recipient of Architecture Magazine's Annual Design Review awards. The publication awarded 21 projects designed by architecture firms located in the United States.
Architecture Magazine refers to the research and academic institution's 625,000 square foot expansion as "a distinctive building, but also one that responds to its context," citing its glass facade and painted aluminum fins. The new 15-story glass-clad tower is located adjacent to the existing Haaren Hall, an early 20th century redbrick structure previously used as the campus’ main building. In an effort to synchronize the two structures that originate from vastly different architectural eras, painted aluminum vertical fins were designed to wrap each side of the glass tower. When viewing the structures from the east, the glass tower’s exterior fins include a red dot silk-screen pattern to blend with the existing redbrick Haaren Hall. When approaching from the west, the tower’s fins are coated by silver-speckled mica-flake paint to accent its glass facade.
Enclos' scope included design/build services for 240,000 square feet of facade, which included curtainwall, skylight, louver and panel systems. Systems include localized blast design.
"High-Performance Facades" is an ongoing series leading up to the Facades+ Conference in New York City, April 11-12. The theme of the two day event is performance. Part Two of this series will appear in an upcoming edition of SkinTec shortly after the New Year.
by Mic Patterson & Jennie Matusova
A definition of high performance, whether used in the context of buildings or their subassemblies (facades), is elusive and nebulous, often incorporating trending key words like “sustainable” and “technologically advanced” to describe works that are often neither. A concise and consistent definition for what constitutes a high-performance facade is simply not found in literature or dialogue today. The difficulty lies in pinpointing the most significant contributors to the performance of a facade, with contenders ranging from metrics such as U-value to the physics of a double-skin facade cavity to the role of facade commissioning. There is no clear answer. However, several leading research initiatives have attempted to hone in on the increasingly exaggerated attributes of high performance facades in architecture and engineering literature.
In its 2006 report High Performance Commercial Building Facades for the California Energy Commission, the Lawrence Berkeley National Laboratory (LBNL) team defined facade performance as a product of technological solutions “based on fundamental building concepts for daylighting, solar heat gain control, ventilation and space conditioning” (Lee et al, 2006, 11). The “high” part of the moniker signifies an intelligent combination of these strategies based on details unique to a project, such as siting, materials and building system integration. Although many effective facade strategies could include passive and relatively low-tech solutions (i.e. correct solar orientation, overhangs, etc.), the reality is often increasingly complex designs that involve advanced materials, automated dynamic components and integrated climate controls.
In America, the tendency towards a more high-tech approach to performative facades is often the result of both clients and architects wanting to create a distinctly “sustainable” image. A roundtable discussion of 24 industry professionals led by LBNL confirmed this mentality, with one architect stating:
"What it comes down to is whether that difference in payback [for an advanced facade] can be justified with the image of sustainability that the client can use as a type of advertising cost. It only works if people can see it. If you can’t look at the building and see that there is something about it and that is sort of a reflection of the sustainability, then there is not as much interest in it." (Lee et al, 2006, 42)
This mindset is a relatively recent phenomenon characteristic of the U.S. marketplace and less a factor in Europe, even though high-performance facades have been a part of European architecture for well over two decades. In Europe, the greater proliferation of advanced facade technologies has been “driven in part by higher energy prices, stricter building codes, and higher expectations regarding the quality of the working environment,” (Yudelson, 2009) as explained in High-Performance Facades: Design Strategies and Applications in North America and Northern Europe, another report for the California Energy Commission by the Center for the Built Environment (CBE). European markets have legislated standards for building envelope performance, whereas American construction has relied on the adoption of voluntary (occasionally incentivized) sustainability standards and green building and product rating systems (LEED, Green Globes, Cradle-to-Cradle).
Nevertheless, CBE’s report assembles a number of fundamental design strategies seen across a range of both European and American case study buildings. The seven key strategies identified are:
- Massing and Orientation
- Solar Control (glazing coatings, fixed and automated shadings, etc.)
- Natural Ventilation
- Double-Skin Facade
- Semi-Conditioned Atria
- Integrated Lighting and HVAC Controls
All of these have pronounced effects on minimizing building energy use while “simultaneously enhancing the comfort and well-being of the building’s occupants” (Zelenay, Perepelitza, and Lehrer, 2011, 1). The most effective and efficient buildings are designed holistically, integrating the facade strategy with other building systems and the overall design. When taken in broad strokes, one can start to see recurring combinations of strategies that have proven effective under certain climate conditions. For example, when combined correctly, integrated facade and HVAC systems in temperate areas such as coastal California can be particularly valuable because the mild climate “provides an opportunity to eliminate the need for cooling altogether” (2). Ultimately, though, the success of facade performance depends on so many other design factors unique to a project that each case must be considered as a distinct challenge without any prescribed solutions. Although more effective, this kind of custom, tailored approach to design makes any kind of quantitative comparison much more difficult.
All of this tends to leave us with more questions then answers:
- What is the relationship between performance and complexity?
- Are high-performance facades/buildings good for the environment (“green”)?
- What is the time scale for high-performance facades, and is it a short or long term solution?
- How do we measure performance, and what metrics define a high-performance facade?
Part 2 of this ongoing series will begin to address these questions and define metrics appropriate to a high-performance facade. Stay tuned.
About the Authors:
© enclos corp 2012
The Architect's Newspaper published yesterday a reclad feature including New York City's famed Jacob K. Javits Convention Center, which is amidst a 459,000 square foot facade renovation and expansion. The article, entitled "Second Acts for Modern Buildings," focuses on the realization of architect James Ingo Freed's original 1982 transparent glass design.
Enclos is responsible for the facade retrofit program, which includes removal of the original 1982 facade and the engineering, fabrication and installation of 459,000 square feet of curtainwall and skylight systems. The convention space — largely in part from its new high performance glazing — is predicted to improve its energy efficiency by 26 percent.
You can read the article in its entirety here.