Energy efficiency has been a major topic within the glass industry of late, especially since New York City Mayor Bill de Blasio’s comments denouncing all-glass buildings back in April. Glass industry professionals spent ample time on the topic of glass and energy efficiency in a webinar yesterday titled, “Professional Roundtable: Perspectives on Glass and Glazing in Design.”

Urmilla Sowell, advocacy and technical director for the National Glass Association (NGA) kicked off the roundtable by asking how industry professionals respond to de Blasio’s remarks.

James O’Callaghan, director at Eckersley O’Callaghan Engineers, said that while the mayor’s statement was bold, it was not entirely educated in respect to how the industry uses glass.

“Fundamentally we use glass to allow us to have light into our buildings, which is a need psychologically. It also has many benefits in respect to how it can be made,” he said. “It’s a relatively economic form to be able to unitize and create façade systems and with that you have historically seen a lot of buildings that are cladded with glass … I’m not advocating that glass is the answer to everything by any stretch of the imagination but I do think it plays a very important part in architecture…”

Dan Weissman, senior associate and director of Lam Labs, used the phrase “everything in moderation” when it comes to glass. He said that there are few alternatives for a material that can maintain thermal weather barriers, let light in and last on the façade of a building for more than 50 years.

Thomas Culp, engineering and strategic consultant and owner of Birch Point Consulting, pointed out that glass can be aesthetic and perform.

“It’s presented as a false choice but there’s an opportunity to do both. Glass can offer views and other benefits of glazing while being energy efficient,” he said, while explaining that recent updates to building codes will take time to go into effect. Culp said that the industry needs to get to a point where new low-E coatings and vacuum insulating glass (VIG) technology are being used and maintained regularly.

In regard to codes, Nick Bagatelos, founder and president of Bagatelos Architectural Glass Systems, added that codes are driving energy efficiency in California.

“The technology is available but the codes aren’t there yet in the rest of the country,” he said.

Another reason high-performance glazing isn’t more widely used is because it can be value engineered out due to being cost prohibitive.

“Architects inherently understand the value and positive impacts of glazing on occupant health and well being … and on real estate values. A well glazed building has a higher real estate value. The question is how we get them to keep the high-performance, energy efficient technology,” said Culp, who suggested conveying to the building owner the financial ramifications of value engineering high-performance glazing out of a project in regard to the human and energy performance side of the equation. He said it’s also important to point out the financial savings in the long term as an existing building as well.

Bagatelos pointed to LEED as an example of what can be done to educate people on the value of energy efficiency.

“Buildings that gained LEED certification 12 years ago, their value is higher today than non-LEED buildings,” he said. “Buildings going LEED are doing so because the developer has seen the value.”

The participants agreed that being brought in early on a project allows the architects to make more informed decisions about the products included in a façade and its engineering. However, some said they are rarely brought in early enough in the process.

The webinar was hosted by Architectural Record and sponsored by the NGA as part of its Glass & Glazing Design Academy.