A building envelope separates the inside from the outside, but it can do much more than that. A building envelope should not only look good, it also needs to perform well by acting as a durable air and moisture barrier, providing potential energy savings and improving indoor air quality and internal climate.
Examine the “building envelope” as a whole: it includes the foundation, walls or exterior finish materials and facades, coatings and glazings, insulation, roof, and windows and doors. High-performance building envelope options are varied and may include several different products that work together as a whole system, such as claddings, metal panels, brick, masonry, concrete, stone or tile, curtainwalls, daylighting and skylighting systems, ICFs, EIFS, and beyond. Also gaining more attention are building integrated photovoltaics and solar systems, living wall systems, rainscreens, strawbale (even in commercial buildings), rammed earth and other innovative green approaches.
Following are examples of building envelope products and buildings that were designed with high-performance sustainability goals in mind.
Apollo Group Inc.’s employees have begun moving into Riverpoint Center, its new corporate campus in Phoenix. Along with celebrating the desert region’s natural colors and materials, Apollo’s design-assist team challenged Wausau Window and Wall Systems to help control the Southwest sun and reduce energy consumption, while maximizing daylight.
Taking an active role in shaping the project’s success, Apollo selected a joint venture design team composed of Carpenter Sellers Architects of Las Vegas and SmithGroup of Phoenix. Sundt Construction was chosen as general contractor, responsible for the overall budget estimated at $107 million. Sundt recommended KT Fabrication of Chandler, Ariz., as the project’s glazing contractor.
Together, Sundt and KT drew on past experiences with Wausau to complete the curtainwall and window system team.
CSA and SmithGroup designed the buildings along the site’s east-west axis maximizing natural light into the open office spaces. Each building’s façade responds to its own exposure: On the west and east, shading is accomplished with narrow, deep-set vertical windows and small apertures that allow views to the outside, while minimizing the amount of exposure to the low sun. On the south, KT fabricated the horizontal sunshades that shield the openings from harsh summer sunlight, while positioned to invite solar light and warmth in winter months. On the north, glazing areas are maximized to welcome year-round daylighting, significantly reducing reliance on artificial illumination and its associated energy costs.
Wausau manufactured a total of 186,000 square feet of window systems ranging from 4¾- to 8¾-inch depths. The majority was factory-fabricated in Wisconsin as vertical silicone-glazed curtainwall, then shipped to KT as knocked-down framing members for installation on site.
Each of Wausau’s systems meets the industry’s most stringent requirements for air infiltration, water resistance and structural integrity. High-performance insulated glass from Viracon was used throughout Riverpoint Center mitigating unwanted solar heat gain and the adjacent freeway noise. Complementing the systems’ high-performance, all of the aluminum was finished in durable, clear anodize by Linetec.
• The National Institute of Building Sciences, under guidance from the Federal Envelope Advisory Committee, has developed a comprehensive guide for exterior envelope design and construction for institutional/office buildings called the Envelope Design Guide, which is continually updated through the Building Enclosure Councils.www.wbdg.org/design/envelope.php
• According to the provider of this Web site, the U.S. Department of Energy, the building envelope is a critical component of any facility since it protects the building occupants and plays a major role in regulating the indoor environment. Consisting of the building’s foundation, walls, roof, windows, and doors, the envelope controls the flow of energy between the interior and exterior of the building. A well-designed envelope allows the building to provide comfort for the occupants and respond efficiently to heating, cooling, ventilating, and natural lighting needs. In this section, information is available on foundations, walls and roofs, and fenestration.www1.eere.energy.gov/buildings/commercial/envelope.html
Situated in southeastern Massachusetts with a panoramic glass façade that capitalizes on water views, the Medical Information Technology Inc. Building, also called MEDITECH Southcoast, is a tribute to the community and a major component of the area’s economic revival. The new four-story, 122,000-square-foot building, located in Fall River, Mass., is home to MEDITECH, a software vendor in the health care informatics industry.
Boston-based Payette incorporated sustainable elements to the building that would capitalize on the natural landscape and scenic location of the site. To provide advanced energy performance and meet Massachusetts’ thermal requirements, the building features an advanced façade-a synergistic, seamless integration of products designed to provide advanced energy performance and indoor environmental quality. Using a collaborative approach, the advanced façade includes high-performance glass, thermal doors and windows, and motorized sunscreen systems that automatically respond to exterior solar conditions and are integrated into the versatile curtain wall.
Kawneer’s (www.kawneer.com) 1600 Wall System1 curtain wall, outfitted with automatic solar-tracking motorized shades to provide maximized daylight and views while offering sunshading, was used in the creation of the advanced façade helping contribute to the overall indoor environmental quality of the building. Additional combinations of high-performance Kawneer thermal products, 7500 Wall curtain wall, 1600 Wall System1 curtain wall, 560 Insulclad Thermal Entrances, 8225TL ISOLOCK Windows and 2000T Terrace Doors reduce thermal transmittance and helps optimize energy throughout the facility.
The new Natural Sciences Building at South Puget Sound Community College, Olympia, Wash., features 6,592 square feet of Kalzip TF800R on its exterior walls and color-matched extruded aluminum flashings. The 52,000-square-foot three-story structure, which is targeting LEED Gold certification, was designed to complement an existing science lab and classroom building on the western edge of the campus. The Kalzip 0.040 gauge aluminum décor helped fulfill both aesthetic and functional needs of the project that was completed in October 2008 by the Miller Hull Partnership. In addition, the Kalzip panels also can be reused or recycled at the end of the building’s lifecycle.
LEED-certified center features manufactured stone
The 25,000-square-foot LEED-certified Little River Canyon Center is situated in the Little River Canyon National Preserve. When completed in early 2009, this teaching center in the heart of an unspoiled wilderness area will serve as the headquarters for the National Park system and as a field school for Jacksonville State University. The architects and planners at the university had an unwillingness to tap the reserves of natural stone in the area, a significant factor in the decision to specify a manufactured stone alternative. A custom blend of 12,000 feet of Eldorado Stone was used around the base of the building, for columns, and even for the entry sign.
Eldorado Stone, which incorporates recycled content into its stone products, such as fly ash, was selected for its cost savings and the reduction in landscape disruption at the site.
“We felt that Eldorado Stone was in keeping with the spirit of the center and what we were trying to accomplish, which was to protect and conserve natural resources,” says Jay Jenkins, AIA, partner at JMJ Architecture. “And best of all, you can’t tell it isn’t real stone.”
Insulating concrete forms are a stay-in-place foam insulation system for energy-efficient, cast-in-place, reinforced concrete walls. This five-story residential condominium located in Huntsville, Ontario, features Nudura ICFs, finished with exterior stone and stucco.
Nudura offers a product line that combines the use of EPS foam with reinforced concrete that can be used in commercial or residential applications. The EPS foam emits no CFC or HCFCs or VOCs and the foam is 100 percent recyclable. In addition, the web material is 100 percent recycled. The company reports that the synergy of these materials forms a structure that is extremely energy efficient by as much as up to 70 percent, air tight and moisture resistant, resulting in a comfortably enclosed space that enables building mechanical systems to heat, cool and ventilate the structure more efficiently.
Green Residential Project incorporates concrete, metal, zinc and other façades
Del-Sano Contracting Corp. has completed Garden Street Lofts, a luxury residential building in Hoboken, N.J., pending a Silver LEED rating. This project was redeveloped from an existing 42,888-square-foot, structural steel, concrete and masonry, former coconut processing and storage warehouse erected in 1919. Del-Sano built a new 35,054-square-foot, seven-story structural steel and concrete addition with gauged metal-perimeter wall framing and a zinc rain screen façade. The addition rises above and is linked to the restored cast-in-place concrete building at the original fifth floor roof level. Energy performance was optimized using special window glass and Viracon Low E VE 1-42 glazing. Designed by Sharples Holden Pasquarelli Architects and developed by Bijou Properties, Garden Street Lofts uses low-emitting, recycled, locally manufactured, and rapidly renewable materials, such as structural steel and zinc facade, bamboo flooring, cotton insulation, FSC-certified wood, FSC IPE decking and siding, no-VOC paints and low-VOC coatings. W&C