During the National Fenestration Rating Council (NFRC) 2020 Fall Membership Virtual Meeting last week, attendees gained insights into commercial glazing sales data and trends in energy efficiency. In the session, “Commercial Fenestration Market Study,” presented by consultancy firm Guidehouse, director-in-charge Ed Barbour, project manager Rebecca Ciraulo and research support Valerie Nubbe gave an overview of the findings.

The study had three purposes. To:

  • Gain insights and understanding of commercial fenestration market intricacies;
  • Gather data necessary to support an estimate of national savings potential of energy efficient fenestration products in commercial applications; and
  • Demonstrate commercial market opportunity for energy-efficient façade and window systems.

Buildings account for approximately 39% of total primary energy use in the U.S. Commercial buildings account for 26% of all U.S. electricity consumption. Advances in commercial energy codes, state and local policies, and government rebates are helping to grow the energy efficient glass market.

Barbour pointed out that 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 benchmarketing data collected today doesn’t explicitly include fenestration.

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

Ciraulo explained that determing who makes the final decision on energy efficient glazing is difficult to trace. She added that data on 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 where 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. Often, fenestration-specific tools are 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.

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. Of the buildings included, only 36% had glass with low-E coatings. Of the glass with low-E coatings, 81% was sputtered and 19% was pyrolytic. Clear glass makes up 48% of the market while tinted makes up 34% and reflective makes up 11%.

Non-insulating glass represents 48% of the market. Nubbe said that triple glazing makes up a higher percentage than expected at 10%. The majority of insulating glass is air-filled (55%), though 43% of insulating glass units include Argon.

According to the study, aluminum/other metal window frames make up 76% of the installed stock, of which 21% have a thermal break. However, new construction frames are primarily aluminum with thermal breaks.

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 about 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.