BOULDER – One of my favorite modern technologies for homes may not be what you think it is, but smart glass technology should be at the top of your list when considering home upgrades. Ten to 25 percent of your heating bill is lost to heat escaping through windows, the U.S. Department of Energy estimates. Aside from installing thicker ones, most of us resort to blinds and curtains as a way to cool down or retain heat in our homes. Smart glass – or light-adaptive glass – is changing that. Installing smart glass in your home can save money on heating and cooling costs, block UV and infrared rays, and control a room’s light exposure. They could also make window coverings like curtains and blinds a thing of the past. Here are the six different types of smart glass you need to know about.

Electrochromic devices use electrical voltage that align tiny particles in a thin film within glass or plastic, allowing control over the amount of light and heat passing through. What does that mean, exactly? You can control the opacity of a glass window with the touch of a button. When darkened, you can still see through the window perfectly, but others cannot see in. Many museums use this type of glass in display cases and picture frame glass to protect the items from damaging UV rays and visible wavelengths of artificial light. Many smart glass products are electrochromic because they can be controlled based on a range of conditions.

Photochromism is a fancy word to describe a color reversal upon exposure to light. When a photochromic object is exposed to UV light, trillions of photochromic molecules in the glass begin to change structure, causing the material to darken. Residential photochromics are a great way to allow just enough light through a window for lighting purposes, while cutting out excess sunlight that creates glare and warms up the house. One of the most well-known examples of photochromism are eyeglasses whose lens darken when exposed to the sun (such as Transitions). Although small photochromic units have been produced in volume as a consumer product, these materials are still being tested for long-term outdoor applications.

As their name suggests, thermochromic objects darken when exposed to heat. Windows that automatically turn shades darker when exposed to the blazing sun are a perfect example, but thermochromic technology has many other practical uses, such as baby bottles that change colors when cool enough to drink, or kettles that change colors when water is at or near boiling point.   

Suspended particle
Windows can go from clear to dark in a matter of seconds thanks to microscopic, light-absorbing particles known as suspended particle devices (SPD). When an electrical signal is sent, the conductive particles line up in a straight line, allowing light to flow through. Once the electricity is taken away, they move back into a random pattern and block light, i.e., darken the window.

The cool part about SPDs is that you can benefit from this technology without needing to replace all the windows in your home. According to How Stuff Works, smart glass developer Research Frontiers has a patent that will enable homeowners to outfit their existing windows with SPD technology. Reportedly, you can power about 15 large SPD smart windows in your home for less electricity than it takes to operate a simple night light. Sign me up.

Micro-blinds are – you guessed it – microscopic thin metal blinds on glass that control the amount of light passing through in response to applied voltage. With no applied voltage, the micro-blinds let light pass through. When voltage is applied, the electric field formed between the two electrodes causes the rolled micro-blinds to stretch out and block light–or basically, darken.

Polymer dispersed liquid crystal devices
Privacy control is at the heart of polymer dispersed liquid crystal devices (PDLCs), which can be used in interior and exterior settings, such as conference rooms, hospital rooms, and bathroom/shower doors. This smart glass is used in residential settings, as well, where it can quickly cut down on lost heating or cooling, and of course, the privacy factor is a big deal for those in the luxury market. They allow for someone on the inside to see out while remaining dark for a person outside. You can buy it in an adhesive-backed roll to simply attach to existing windows.

We can’t wait to see where this technology will take us in the future, and hope this list inspires you to take a fresh look at the windows in your home.

Jennifer Egbert is an award-winning, top-producing Realtor with more than eleven years of experience. She is a licensed residential agent that specializes in the Boulder market. She is an expert in Boulder Luxury neighborhoods, home builders and most current market conditions. To learn more about the Boulder real estate market, visit,  follow her on Twitter and Facebook or call 303.442.3180.