Call it a big glass revolution.

No longer bound by rules that once effectively blocked the use of oversized glass in exterior home design, residential architects, builders, and developers can now offer a dazzling natural light show that’s wowing millennial and baby boomer home buyers looking to blur the lines between indoor and outdoor life.

This big glass transformation comes without “… the high energy bills, drafty interiors, outside noise, and aesthetic limitations” usually associated with big glass design, says industry analyst Mariel Behnke of The Freedonia Group, a leading international business research company.

And there’s good news for builders’ bottom lines too: About three out of four surveyed home buyers say they will pay a $4,000 premium for a large retractable glass sliding door, according to independent research and advisory firm John Burns Real Estate Consulting.

The race is on to meet this surging demand with several big glass strategies, including:

Mulling Windows

Home designers and builders have long grouped a series of window assemblies (mulling) to create a larger glass expanse, say for a dining or living room. The difference today is the vast design palette architects and builders have to work with. Mulling arrangements can include many window formats from double- and single-hung, glider, awning, and casement to innovative corner windows for eye-catching panoramas.

Interestingly, the aesthetic limitations that once stayed the hand of traditional home designers and builders has all-but disappeared. Big glass is everywhere, not just contemporary homes. Kris Hanson, senior group product manager at Minnesota-based Marvin Windows and Doors observes, “Big glass has expanded well past contemporary design to include a broad array of home plans.”

Large Glass Doors

Home buyers expect a more seamless transition between outdoor and indoor living space. The growing class of glass doors offers a variety of styling arrangements, from lift-and-slide and multi-slide to bi-fold. Consider the multi-slide glass door, for example, as the outdoor gateway. Marvin’s multi-slide door is available in lengths up to 56 feet and heights up to 12 feet, helping erase the line between outdoor and indoor.

Of course, breakthrough door sizing is only made possible because of corresponding improvements in glass door energy performance. Specifying big glass doesn’t mean a larger HVAC system is required. “We offer larger door sizes without sacrificing energy efficiency or overall performance,” explains Hanson. For example, multi-slide glass doors from Hanson’s company now meet or exceed LC-PG50 rating and offer an extremely low standard U-Factor of 0.28.

Large Windows

Home buyers like the practicality and familiarity of their single-hung, double-hung, and casement windows. They just want them … well, bigger. For example, Marvin double-hung windows are now available in standard sizes up to 5 x 10 feet – yes, 50 square feet for a single unit. Super-size that with two or more assemblies in a mulled arrangement, and ordinary quickly morphs into extraordinary. Single fixed casement windows are now offered at sizes up to 6.7 x 10 feet, flooding home interiors with 67 square feet of natural light.

What’s next? Bet on bigger.

As Hanson puts it, “We’ll continue to introduce larger windows and doors for even more natural light and unobstructed sightlines. Today nearly any interior space can be transformed by big glass to feel even larger and more connected to the outdoors.”