A home with a view: New glass technology allows for bigger, better windows in the Rockies

The splendor of nature inspires us to live in the mountains, so sometimes it seems counterintuitive that homes built more than 20 years ago didn’t accentuate the mountain views as much as they do today. But window technology just hadn’t come far enough for expansive glass wall systems to highlight the mountain peaks, golden aspens or green valleys outside homes. 

Although window technology still doesn’t provide anywhere near the insulation value an actual wall does, the industry has made significant advancements in such factors as the size of windows and sliding glass doors and their ability to limit ultraviolet rays, which fade furnishings, floors and everything else sun rays hit. 

A brief history of transparency 

When humans first melted quartz, or silica, sand to manufacture glass, they could only fabricate small pieces, which contained imperfections, so they mounted them in a number of small window panes. Until around the 1950s, these single-paned glass windows were extremely drafty, but in the ’50s and ’60s, companies began to build double-pane windows, employing an air space between the glass pieces. 

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“It was a really good invention,” said Caz Casber, founder and owner of All Window & Door Services in Edwards, explaining how the air space helped prevent some heat loss. 

“It’s almost hard to tell between a window and a piece of art.” Adam Harrison, principal at Shepherd Resources, Inc.

In the 1970s and ’80s, manufacturers began to insert argon, an inert gas, between double- and triple-pane windows. 

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“It was a good addition to energy savings, but even with these two (or three) panes and inert gas, we’re still a long way (from superior insulation),” he said. 

Plus, gas expands at higher elevations, so it’s just not practical in the mountains, which is one reason engineers came up with low-e (low-emissivity) coatings on windows. The coatings, which often come on all sides of double-pane windows, minimize the amount of ultraviolet light (responsible for fading) and infrared light (responsible for transmitting heat) that passes through glass.

The idea involves keeping heat inside and cold out during the winter, and achieving the opposite effect during the summer months. Low-e windows reflect heat so when the interior heat tries to escape to the colder winter temperatures outside, it actually bounces back to the inside of the home, reducing heat loss; the reverse occurs in the summer. Passive low-e coatings maximize solar heat gain in a home, while solar control low-e coatings limit the amount of solar heat that seeps into a building.

According to energy.gov, low-e windows cost about 10 percent to 15 percent more than regular windows, but they reduce energy loss by as much as 30 percent to 50 percent. At first, they had a fairly high tint factor, which homeowners didn’t like, but that quickly changed. 

“Low-es have come a long way,” Casber said. “Now you can hardly tell they are low-e.” 

Another technology that’s been around for the past 20 or so years differs from the microscopically thin, transparent metallic coating employed in low-e glass, in favor of electrochromic glass (or “smart” glass). This type of glass changes from clear to opaque at the push of a button, which applies an electrical voltage across the windows. A variety of electrochromic glass exist: Some darken and become translucent while others become mirror-like and opaque. 

“They are incredibly expensive, but a lot of people like them,” Casber said.  

Of course, the best protection against damaging sun rays comes from awnings and shutters, which prevent direct sunlight from streaming inside, he said. 

“With even the best low-es, you still get fading carpets and furniture,” he said. “They’re still working on keeping harmful rays out and getting warm rays in (during winter). That’s the technology we’re working on.” 

And then there’s the overall insulation value, which has a long way to go. 

“You’re still not going to be able to gain the insulation value of a wall, which ranges from R-13 to R-49, the latter of which are common for ceilings and attics,” said John Warnock, owner of Highlands Glass in Eagle. “The best windows may reach R-5.” 

Of course, there’s also the problem of building a home “too tight.”  

“We all want to save energy, but along with that, we’re making our homes unhealthy because (we’re building them) too tight. It’s saving energy, but it’s not saving our lives,” Casber said, adding that the solution lies in proper air ventilation. 

Indoor/outdoor living 

Obviously, the lure of expansive glass walls and windows involves integrating the outdoor mountain environment with a comfortable interior living space. 

“It’s nice to be able to put glass in and show off the views; why would you not, when you have a beautiful view,” Warnock said. 

Advancements in window and glass door technology have allowed architects to design modern masterpieces characterized by extensive glass. 

“Twenty years ago, we weren’t able to incorporate sliding systems to the point of where we can today,” said Adam Harrison, principal at Shepherd Resources in Edwards. 

One recent project involved huge sliding glass, which tucks behind a wall filled with a large painting when opened. Another literally opens up a corner of the living room onto a large deck overlooking Gore Creek, giving the appearance of a floating ceiling and resulting in an airy, expansive indoor/outdoor living area, complete with interior and exterior fireplaces. 

Companies like NanaWall can build to specifications with minimal sightlines and various finishes and materials, from open-corner designs to unhinged pairs, segmented curved walls, no-floor tracks and more. 

With each project, architects like Harrison plan window placement wisely. For instance, when installing the huge glass walls that open up in the previously mentioned corner that overlooks the river, they strategically planned a metal floor grate to provide heat in front of one of the floor-to-ceiling windows, to keep the inside toasty. 

“All glass in a house results in bigger fluctuations in temperature, but you plan for that in the design,” Harrison said. 

In addition to highlighting views and bringing in more light, architects can plan for passive solar. One example may be not only placing the window where the sun is most intense, but also installing a stone floor, which holds much more heat and thus, releases heat as the sun goes down, as opposed to a wood floor. 

As glass manufacturers construct larger pieces of glass, the possibilities become even more far-reaching. Up until a handful of years ago, architects were limited by approximately 6- to 7-foot pieces of glass, but now companies, especially European ones, are beginning to make pieces measuring 10’ x 8’. 

“The typical window supplier will still say 6 to 7 feet, but we’re starting to find glass companies willing to break out of that size limit,” he said.  

In addition, glass and windows come in just about any shape and configuration, from circles to triangles, Casber points out, resulting in stunning-looking homes from both the interior and exterior. 

“The dynamics looking at it from the exterior are just wonderful. It gives us the ability to break up the materials of a home and provide a much more modern look. It’s almost hard to tell between a window and a piece of art,” Harrison said, adding how, these days, as more and more windows frame views, they essentially transform into a “piece of art.”