Fiberglass windows come of age

Storefronts and window walls

Fiberglass windows can reach up to 6.5 m² (70 sf) in a fixed frame and can be factory mulled and field mulled into storefront and window wall configurations. Due to improved energy efficiency, fiberglass frames can stay almost room temperature even on cold days and condensation resistance is superior. Triple pane is available up to 4.6 m² (50 sf) and offers even better U-factors.

With glazing pre-installed into the frames at the factory and easy-to-install field mullions, installation for fiberglass storefront windows can save costs involved with panning, field glazing, and mullion installation.

Cost comparisons

Fiberglass frames are competitive with aluminum frames, though it is difficult to directly compare prices due to wide swings in quality and location. One important consideration is fiberglass frames are factory glazed and factory mulled when possible (depending on size—these storefront windows are 4.6 m² each and factory mulled two wide), considerable savings can be realized when comparing installation costs of site glazing aluminum frames.

Glazing innovation

There are many window manufacturers using all types of materials and glazing science, so innovation and cost savings are the driving force for gaining a competitive advantage. One new development is a new style of operator for casements and awnings.

For years, casements and awnings have opened and closed with a crank. Now, a totally new sliding style of operation has been introduced that also meets the difficult 2.3 kg (5 lb) operating force Americans with Disabilities Act (ADA) requirement up to certain sizes. With the slider mechanism in the jamb, it does not interfere with shades and blinds opening or closing.

Summary

While similar in thermal efficiency, fiberglass frames are stronger and more durable than vinyl frames. While generally more expensive than vinyl, the strength of fiberglass allows for larger frame sizes, narrow mulls, and storefront capabilities.

Fiberglass window frames offer the strength, durability, and narrow sightlines of aluminum but are more thermally efficient, smoothing out heating and cooling peak loads, and providing better condensation resistance. Similar in cost to mid-priced aluminum windows, significant savings may be realized on labor costs when installing factory glazed and mulled fiberglass frames.

Fiberglass window frames are rapidly gaining popularity in commercial projects from multifamily to hospitality and new innovations in operating hardware make them attractive for senior livings. Offering flexible design and installation options, high-performance structural and thermal attributes, and sleek, contemporary sightlines, fiberglass windows make a great alternative to vinyl and aluminum windows and are worth considering on future projects.

Authors

George Ramsay, CSI, CDT, is the national architectural solutions consultant at Pella Corporation. Ramsay has more than 20 years of experience in building materials, specializing in working with the architectural and design community. He works around the country providing technical and design assistance, specification writing, and guidance, and is focused on making architects, and specification writers, fenestration challenges less painful. Ramsay served as president of the CSI-MSP Chapter 2016-2017 and was on the board of directors for five years. He has served on various committees locally and regionally over the last 15 years for CSI-MSP and is currently treasurer for the North Central region. Ramsay is a graduate of the College of Saint Scholastica in business management with honors.

Bryan Warring is the product marketing manager, Impervia fiberglass at Pella. With more than 13 years in the building material and construction industry, Warring’s experience is multi-faceted; it has spanned areas of the industry including retail store management, key account management, sales management, supply chain, and category management. He joined Pella in 2020 to take on the new challenge of leading and driving the Impervia fiberglass strategy. Warring graduated from Illinois State University in 2008 with a degree in marketing and earned a dual MBA in marketing and operations management from Regis University.

Jaron Vos is the manager of corporate architectural solutions team at Pella. Vos holds a bachelor of science in construction engineering and has assisted architects, contractors, and consultants with their fenestration application needs for 18 years.