Studies show that bright buildings can produce bright students. At the new College of Business Administration at California State University – San Marcos (CSUSM), they produce significant energy savings, too.

That’s because the building, designed by Gail Bouvrie, AIA, of AC Martin Partners in Los Angeles, is one of the first buildings in the country to feature Solarban 70XL glass, a revolutionary solar control Low-E glass from PPG. Another PPG product, Duranar coatings, was used to protect and beautify the aluminum extrusions used in the window and door frames and other metal architectural components.

A light-filled, 72,500-square-foot complex, the new building, also known as Markstein Hall, incorporates 27 classrooms in one three-story wing and 88 faculty offices in a separate four-story wing. High-tech accoutrements include teleconferencing equipment in each classroom, high-speed internet access wired into every desk, and state-of-the-art video and acoustical components to facilitate both on-site and distance learning.

Despite all these technological embellishments, perhaps the building’s most significant yet understated advance is the glass that envelopes it.

AC Martin Partners was the architectural firm that designed the Joe Serna Jr. California Environmental Protection Agency Headquarters Building in Sacramento, a LEED Platinum-Certified structure that is widely regarded as the “greenest” high-rise building in the country. Ken Lewis, AIA, a principal with the firm, was in charge of Markstein Hall. As a leader of such an environmentally progressive firm, it’s no coincidence that one of Lewis’ goals was to make Markstein Hall as sustainable as possible. It is also the reason he chose to make the new building one of the first in the country to capitalize on the performance and aesthetic benefits of Solarban 70XL glass.

More Light, Less Heat

Introduced at the GreenBuild 2005 International Conference and Expo, Solarban 70XL glass constitutes a major advance in the architectural glass industry for two reasons. First is the glass’ remarkable solar control performance. Combined with traditional clear glass in a conventional one-inch insulating glass unit, Solarban 70XL glass blocks up to 73 percent of the sun’s solar energy, while transmitting more than 63 percent of its visible light. The result is an unprecedented Light to Solar Gain (LSG) ratio of 2.33.

Second is the glass’ transparency. Solarban 70XL glass is billed as the only architectural glass in the industry to combine such an exceptional level of solar control with a clear glass aesthetic. In fact, before the introduction of Solarban 70XL glass, the highest-performing non-tinted solar control, Low-E glass transmitted 70 percent of the sun’s visible light in a one-inch insulating glass unit, while blocking only 56 percent of its solar energy. The resulting LSG of 1.84 was 21 percent less than that of Solarban 70XL glass.

The potential energy savings associated with Solarban 70XL glass was highlighted in a recent study conducted by an independent energy and environmental research firm. The study compared the energy performance of six glazing configurations, including several competing solar control Low-E glasses, on three common building types in 12 North American climates. It showed that architects and building owners could cut capital investment in a building’s cooling plant by up to 26 percent when substituting Solarban 70XL glass for other leading solar control Low-E glasses. The study also showed that building owners could anticipate on-going energy savings of 3 to 5 percent annually for buildings constructed with Solarban 70XL glass (see chart at bottom left).

Real World Performance At San Marcos

Thanks in part to Solarban 70XL glass, building owners have realized a significant and immediate payback on their initial building investment.

For instance, Lewis estimates that by specifying Solarban 70XL glass for Markstein Hall, he was able to lower mechanical costs for the building by $2.00 to $3.00 per square-foot. These savings were related primarily to a lower chilling capacity requirement, as well as smaller fan sizes and ducts. Yet, these initial cost reductions were just the beginning. Working closely with San Diego Gas & Electric (SDG&E), Lewis and his building team were able to earn more than $100,000 in incentives through the utility’s Savings By Design program.

According to program administrators, Markstein Hall is expected to generate annual energy savings of almost 500,000 kilowatt-hours, or approximately $75,000 per year at current energy prices.

While Solarban 70XL glass does dramatically reduce solar heat gain, it is not the sole reason for the Markstein Hall’s energy efficiency. Instead, the glass functions as part of a comprehensive energy management system featuring a demand-control ventilation system and a carbon dioxide sensors that can trigger fresh air intake, helping students to stay alert during their studies.

Another highlight is multi-switched, multi-level lighting fixtures that combine compact fluorescent, linear fluorescent, metal halide and other fixtures with abundant natural light to provide direct and indirect light. Not only does the natural light and fresh air contribute to energy savings; the combination is expected to enhance student performance as well.

The glass fabricator was Oldcastle Glass, Los Angeles. The glazing contractor was Division 8, Inc. PPG products used on Markstein Hall were PPG IdeaScapes Solarban® 70XL Glass and Duranar® Coatings Sunstorm Silversmith.