U.S. Naval Academy enhances daylight and energy savings with dynamic glass

A good case in point is the U.S. Naval Academy in Annapolis, MD. A leaky metal roof at the Academy’s McDonough Hall was transformed into a glass roof that provided abundant daylight and energy savings into the historic building using SageGlass®.  

McDonough Hall is one of the original buildings constructed on the Naval Academy campus, and today serves as an athletic facility. When the metal roof required replacement, the Navy saw an opportunity to bring daylight to the dreary interior by adding more skylights. But Navy architect Tony Freitag wanted to go one step further: he sought to improve the building’s energy performance and maximize daylighting by replacing the metal roof with one made of glass.

“The challenge was, if we made an all-glass roof, how would we avoid ‘poaching the people inside of the building,’ so to speak. The space is already hot and humid, so controlling solar heat gain was a major concern,” Freitag said.

Due to the Hall’s historic architectural significance Freitag ruled out solar shades as they would have altered the original design integrity of the building. Mechanized internal shades and blinds did not make sense due to the roof’s hard-to-reach location and the fact that they would negate the purpose of the glass roof. Therefore, Freitag began researching new options.

Freitag and his team ran some initial building energy calculations based on using electrochromic glass and discovered it would reduce the building’s HVAC cooling requirements by at least 18 percent.

“I took those findings all the way up the chain of command and presented the idea of using dynamic glass. That’s how a simple little project of fixing a leaky roof turned into a sustainable, money-saving, cutting-edge renovation that helps out the whole eco-system of the building,” Freitag said.

Those who have experienced the space since the addition of the SageGlass skylight have expressed enthusiasm about the improved atmosphere. “This part of the building was once the old exterior façade with beautiful big stone arches that were filled with windows. When those windows were removed and the metal roof and wall installed, the space lost a lot of its charm and brightness. The SageGlass skylight creates a bright space with natural light and enhances the daylight in adjacent spaces as well. Everyone I’ve talked to, including the athletic department and military leaders, believe it’s a vast improvement,” Freitag said.