Energy & Environment

Energy Efficient Glazing is Growing, but Hindered by Market Dynamics

Buildings account for approximately 39% of total primary energy use in the U.S., with commercial buildings accounting for 26% of all U.S. electricity consumption. That’s just one of the insights from the National Fenestration Rating Council (NFRC) 2020 Fall Membership Virtual Meeting. The session, titled “Commercial Fenestration Market Study,” was presented by Guidehouse director-in-charge Ed Barbour, project manager Rebecca Ciraulo and research support Valerie Nubbe.

Focus on Performance

Advances in commercial energy codes, state and local policies, and government rebates are helping to grow the energy efficient glass market. Barbour said the role of fenestration in meeting building-wide performance targets will likely be muted without more guidance on the potential contribution and benefits of energy efficient fenestration. He added that most commercial building energy use and benchmarking data collected today doesn’t explicitly include fenestration.

According to the study, energy efficient glazing adoption is hindered largely by market dynamics rather than a lack of technological innovation.

Ciraulo explained that determining who makes the final decision on energy efficient glazing is difficult to trace. She added that the data upon which products were ultimately installed is rarely collected and standardized unless change orders are followed closely. According to the study, energy performance often takes a back seat in selection because energy efficient products often have higher price points.

“We’ve found in interviews that window selection is often driven by visual aesthetic requirements, especially related to clarity,” said Ciraulo. “Building owners and developers tend to demonstrate commitments to sustainability via highly visible selections such as green roofs or solar panels.”

However, thermal comfort also is key to increasing usable floor area, especially when tenants occupy the space for long periods of time. Schools and government buildings tend to install more energy efficient windows than other sectors due to building longevity and because they have a higher tolerance of longer returns on investment.

The study also showed that architects and building engineers only use a handful of modeling tools and don’t change their go-to tools. Fenestration-specific tools are often used when designing complex assemblies. Another finding was that fenestration rating and certification programs drive compliance but rarely window selection due to a lack of understood program differentiation within the building industry.

“Thermal certifications often are viewed as an added benefit and don’t impact the bottom line or health and safety,” said Ciraulo.

A Closer Look

Nubbe then gave an overview of installed building stock. Guidehouse relied on building sample data from six sources with more than 16,000 building samples total in addition to its own survey.

Nubbe also explained 2017-2020 average commercial window sales. Low-E glazing represents 84% of sales, primarily low-solar gain and sputtered technology. Dynamic glass, an emerging technology, represents approximately 1% of sales.

Ten percent of fenestration sales are single-pane glass while 78% is double-pane and 12% is triple-pane. Argon makes up 49% of insulating glass sales compared to 48% for air, 3% for krypton and 0.6% for vacuum insulating glass.

Aluminum frames with a thermal break make up 65% of sales compared to 22% for aluminum/metal, 8% for vinyl, 2% for wood and 3% for fiberglass/composites.

“Newly constructed buildings have significantly higher window-to-wall ratios than existing buildings. The majority (51%) have ratios over 25%. Office buildings have the highest percentage of fenestration area,” said Nubbe.

While energy efficiency has become increasingly important over the past decade, it’s still hindered by market dynamics. There are opportunities for the industry to reduce upfront costs; adjust the design-bid-build process; increase education; continue code advancement; increase compliance and enforcement; and integrate fenestration-specific information into industry standards and state and local policy planning.

Keynote Address

The NFRC Virtual Conference also included a keynote from Edward Mazria, founder and CEO of Architecture 2030 and American Institute of Architects’ 2021 Gold Medal Winner.

“We know now that we are in a full blown climate Emergency,” he said. “Fossil fuels and CO2 emissions are the issue of the day and timing is everything.”

His conversation centered around climate budgets and how to create a carbon positive environment by 2040. He explained that existing buildings are responsible for almost 50% of all emissions.

“… By 2030, you have to electrify those buildings and use renewable for the electricity,” said Mazria. “You have ten years to do it, and you need to provide incentives to get people to go first.”

He said that adding these types of policies will not only reduce building operations by 65%, but will save a huge amount of embodied carbon.

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