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.
With the overall theme of performance backed by quantitative data, the University of Southern California School of Architecture’s bi-annual Facade Tectonics conference concluded on Friday with a diverse discussion of design considerations and academic research. Harris Hall sheltered the conference crowd on one of Los Angeles’ rare rainy days, where inside, the university’s winter summit featured presentations by many industry leaders focused on advancing building facade technology.
Nick Bagatelos, president of BISEM-USA, opened the event with a presentation on prefabricated building-integrated photovoltaic (BIPV) wall panels targeting net-zero performance. While Bagatelos’ research acknowledged that a vertically oriented photovoltaic system would yield only 72% of the energy obtained by an optimized rooftop array on a unit basis, vertical applications can provide a substantial increase in overall energy output because of the larger area of the facade as compared to the rooftop, especially in high-rise buildings. BISEM currently offers BIPV cassette systems that are prefabricated with electrical hardware included, providing a simple, plug-and-play product for glazing installers. Bagatelos claims his product performs to demanding European energy standards, but with the low price tag required by the American marketplace.
“Cost effective is key in America,” Bagatelos said. “During the one year mock-up of my BIPV wall system’s testing, price of the material alone dropped 8%.”
USC assistant professor of architecture Joon-Ho Choi followed with the first of many academic research studies presented at the conference. Choi’s ongoing project involves evidence-based sustainable design and the environmental impacts of buildings. His aim is simple: minimize the risks of high performance buildings to owners and developers. In this pursuit, Choi has created a database compiled from the U.S. Green Building Council and post-occupancy performance data. Users input a number of performance metrics to receive a predicted post-occupant performance, with particular focus given to climate considerations.
Rounding out the morning session were Jim Frawley, southeastern area manager at SIKA, with a presentation on the increasing strength of structural silicone; Amy Hackney, senior project manager at Simpson, Gumpertz and Heger, with a presentation on the do’s and don’ts for vegetative roof design; Reuben Freed, director of research at Greenscreen, with modular living wall considerations; and a collection of USC Viterbi School of Engineering graduate students with a life-cycle analysis of living wall systems.
Returning from the lunch break, umbrellas in hand, conference attendees reconvened for a presentation lead by Erik Johnson, associate professor of civil engineering at USC’s Viterbi School of Engineering. Johnson presented a sampling of student research on how shading fins can double as tuned mass dampers in the event of a seismic event, commenting that “smart buildings must be a synergy of a number of systems.”
Kyle Konis, assistant professor of architecture at USC, talked about problems resulting from the use of obsolete daylighting simulation methods and metrics. Konis identified the three main issues — outdated legacy metrics, inaccurate sensors and controls, and crude “fake sky” simulations — as the context for his research on developing luminance metrics based on quality of light rather than quantity.
In a following presentation, Judson Taylor, senior principle at Simpson, Bumpertz, and Heger, claimed, “The most sustainable building is an existing building, particularly when we can extend its lifespan.” Using the term “green retrofitting,” Taylor explained in detail the energy savings associated with overcladding, backed by data showcasing anticipated payback time.
On a different note, Mark Perepelitza, sustainability resources group manager at SERA Architects, followed by discussing integrated facade design in high performance applications. Using several case studies from SERA and his research from the Lawrence Berkeley National Laboratory, he stressed the importance of accurate digital simulations to measure indoor environmental quality (IEQ). “Today’s advanced buildings are tomorrow’s baseline,” Perepelitza concluded, noting the rapid evolution of green standards and rating systmes.
Echoing the sentiment, YKK AP America brand manager David Warden wrapped up the conference with a discussion on ways to maximize the thermal properties of modern facades. From a performance and economical standpoint, Warden sees the most opportunity in the building envelope’s framing members. “Advanced framing is the most cost effective first step,” emphasized Warden, backing up the claim with research data showing that the most impactful addition to a framing system in modern curtainwall design is a thermal break; a thermal isolator between the facade system and the supporting building structure.
Throughout the one-day summit, question and answer sessions veered to one reoccurring theme: building codes. The Q&A following this final session was no exception, with Warden predicting, “Codes will have the greatest influence and role in pushing the capabilities of future high performance facades.” The consensus was that, while progress is being made through the adoption of voluntary standards and rating systems, green practices will ultimately need to be legislated as mandatory building code requirements in order to achieve sustainability goals in the built environment. The diverse conference attendees are obviously preparing for this eventuality.
Click on image to begin slideshow.
Construction of the New San Diego United States Courthouse is nearly complete. Tenants began occupying the 16-story tower located in downtown San Diego the week of November 5, with the initial court hearing scheduled for the first week of December. The 467,000 square foot structure is the soon to be home of six courtrooms and 12 chambers for district and magistrate judges, in addition to office space.
Enclos provided comprehensive design/build facade services for the project's nearly 300,000 square feet of facade. Design considerations included both oversized and blast-resistant wall systems. Enclos' strategy was to unitize as many wall systems as possible to ease field installation. Unitized systems were ultimately developed for the glass, terracotta, soffit and canopy wall types. Additional scope of work included a transparent glass clad lobby, point-fixed glass, skylights, curved glass, aluminum metal panels (flat & curved), perforated metal panels, sliding and swing doors.
Additional information on the New San Diego United States Courthouse is available here.
Nearly 200 people attended the COLLABORATION symposium.
After a trio of successful events in 2012, COLLABORATION: The Art & Science of Building Facades continues to receive accolades from the AEC industry. Be sure to check out Black Spectacles’ video recap from last month’s Chicago conference, themed “Facades + Innovation,” here.
- Thomas Brock, Illinois Institute of Technology
- Diana Darling, The Architect’s Newspaper
- Jennifer Marmon, PAR
- Mic Patterson, Enclos
- Bradley Samuels, Situ Studio
- Mark Sexton, Krueck + Sexton
- Jonatan Schumacher, Thornton Tomasetti
COLLABORATION: The Art & Science of Building Facades conference is a tri-annual event that gathers leading architects, contractors, consultants, manufacturers and academics to impart new perspectives on opportunities for innovation in the delivery of the building skin. The event continues throughout 2013 in New York City (April 11-12), San Francisco (July 11-12) and again in Chicago next fall. Please visit The Architect's Newspaper for ongoing conference updates.
by MIC PATTERSON & TYLER TUCKER
Prime among performance and design considerations within the realm of facade systems today is the utilization of transparency to provide natural daylight to the building interior, while simultaneously controlling solar radiation and glare. In addition to the use of high-performance glazing materials, shading systems have become a primary strategy in affecting a balance between these often conflicting objectives.
An efficient shading strategy starts with appropriately considered building orientation and configuration. Passive design features such as deep overhangs can provide shade to facades exposed to solar radiation. This approach was used by Murphy/Jahn Architects on the Main Terminal Building of the New Bangkok Airport.
On the other hand, dense urban environments often present limitations to building orientation and configuration, and façade retrofits are generally limited to the constraints of the existing building. These situations may require more aggressive façade interventions in the form of fixed or dynamic shading devices.
Shading systems can be located on the exterior or interior of the building façade. Fixed exterior horizontal or vertical fins can be integrated into the façade system to shade glazed areas. As always, much depends upon climate and location, but in North America, horizontal fins tend to work best on a southern façade. Vertical fins become more useful on the east and west elevations, but a careful combination of the two will usually provide the best results.
Exterior solutions have the significant advantage of stopping the solar radiation before it passes through the building skin, thereby greatly reducing the potential heat gain. The disadvantage is that these systems are exposed to local climate conditions that can easily result in costly maintenance requirements, especially with active shading systems. One justification for the use of costly double-skin façade designs is that they provide a sheltered cavity for the location of shading mechanisms. The Loyola University Chicago: Richard J. Klarchek Information Commons, for example, includes automated aluminum louver blinds within a west-facing double skin cavity that are raised, lowered and adjusted to control head gain and glare (provided by Warema).
Exterior blind systems, while not inexpensive, have been used with success in Europe for decades. These systems have become available in the United States in recent years, and their use is gradually increasing. Operable exterior louver systems have also been used as custom solutions for solar shading.
Still, the maintenance and cost considerations associated with exterior solutions result in the prevalent use of interior shading systems. These systems are most commonly either vertical or horizontal (Venetian) slat blinds, or roller blind systems. Slat blinds utilize adjustable overlapping blades while roller blinds are flexible continuous membranes. Both types are available in a range of light transmission properties from opaque to nearly transparent, achieved through the use of materials with varying translucency and/or the perforation of materials to achieve the desired light transmission. These systems can be automatically controlled, manually controlled, or automatic with manual override. Automated systems are most effectively integrated with the building management system (BMS), which typically integrates the shading and lighting systems with sensors and controls to optimize deployment in response to changing interior lighting conditions induced by a dynamic exterior climate. A successful system can maximize available daylight to the interior, minimize glare, optimize daylight penetration, and minimize solar heat gain. Optimizing available daylight to the building interior minimizes the use of electric lighting, the leading contributor to electricity consumption in buildings, which are in turn responsible for the consumption of 72% of all electricity produced in the United States. Electric lights also produce heat, so reducing their use can also reduce a building’s cooling loads, further reducing energy consumption.
The Dynamics of Solar Behavior
Optimizing daylighting to the building interior can represent one of those rare something-for-nothing opportunities. Relatively minor design decisions can produce significant results. The many variables involved in solar behavior, however, make the prediction of results from iterative design modifications something of a challenge. Best practices for daylighting include the following considerations:
- Building location and orientation
- Interior luminance requirements
- Local climate conditions
- Building geometry
- Daylight redirection and distribution
- Location and percentage of façade transparency
- Properties and performance of glazing materials
In the early days of daylighting and solar architecture, analysis was limited to manual techniques and simulations involving such tools as sun-path diagrams, solar charts, and devices like the heliodon. These may have been cumbersome and time-consuming techniques, but they were also the source of seminal solar design theory and architecture. The groundbreaking work of Ralph Knowles and the definition of the solar envelope were accomplished with the extensive use of a heliodon.
Contemporary facade designers benefit from the development of sophisticated computerized simulation tools that both render and quantify building energy performance and daylighting behavior. These tools offer the advantage of nearly immediate feedback, and facilitate an iterative process of design exploration that can yield optimal results. Software programs such as Autodesk Ecotect use the sun position and desired shading periods to generate optimized shading forms (in addition to providing whole-building energy analysis). Radiance is a sophisticated lighting simulation and rendering tool available free of charge from the Lawrence Berkeley National Laboratory. Other software tools such as Rhinoceros, in conjunction with Grasshopper and Galapagos, can use scripted optimization routines to generate and modify forms (for example, exterior louver strategies), simulate their position, evaluate their performance, and make modifications based on that evaluation in an iterative process. The results are optimized, parametrically driven shading solutions in response to key application variables. The output typically includes renderings and visualizations as well as related charts, graphs, and supporting performance data.
As a curtainwall design-builder, Enclos is ideally positioned to provide integrated shading solutions for the building façade. Working with our clients early in the conceptual design process in a design-assist role, we can participate in and facilitate system design and simulation. Our unique rapid-visualization work process brings conceptualized form into 3D with unprecedented speed. We can simultaneously provide real-time budget and constructability analysis, thereby creating an informed decision-making environment for the design team. Visual and performance mockups are typically the last step in finalizing the design prior to moving directly into the manufacturing and installation phases. The responsibility for the complete implementation of the building skin provides us with maximum opportunity to integrate the shading strategy with the façade system design. Rather than being treated as separate systems, the shading systems can become part of our prefabrication strategy and built right into the façade modules under factory-controlled conditions.
Decades of experience in the design development process have taught us a certainty: the early involvement of a facade contractor is advantageous to all with stock in the building façade; be it owners, developers, architects, contractors, and eventual building occupants. This becomes truer as the increasing performance demands on the building skin result in escalating system complexity. The integration of shading systems as a component of the building façade is just such a case in point.
 Knowles, Ralph. Energy and Form. Cambridge, Massachusetts and London, England, MIT Press, 1974.http://apps1.eere.energy.gov/buildings/tools_directory/ for a comprehensive listing of daylighting and related software tools.
Following is a list of leading industry providers of architectural shading systems and related technology. This is intended only as a courtesy to our readers, and is in no way an endorsement of these companies or their products. It is incumbent upon the project team to rigorously evaluate and qualify these and any other providers of building system products and services.
About the Authors:
© enclos corp 2012