Passive cooling can add aesthetic value and sustainable options for keeping a home cool in a heating climate.
By Leandra Beabout
Before this summer’s heat wave in Europe and California’s massive McKinney Fire, trend forecasting company WGSN predicted rising demand for homes outfitted with creative cooling solutions. Additionally, 63% of REALTORS® say energy efficiency has proven either very valuable or somewhat valuable in listings, according to National Association of REALTORS® data.
When it comes to sustainable cooling, though, air conditioners with good Energy Star ratings, though popular and well known, are only the tip of the iceberg. Developing an eye for climate-adaptive design—that is, homes with weather-resistant features baked into the architecture itself—can put your business on the leading edge.
Passive Cooling: A Unique Selling Point
“Passive cooling refers to any means of cooling that doesn’t use compressors, fans, pumps or any other form of powered machinery,” says Alexandra Rempel, assistant professor of environmental design at the University of Oregon. In other words, passive cooling keeps homes comfortable without gas or electricity.
Incorporating multiple passive cooling features in a property can cut energy bills by more than 50%, according to architect developer Jason Boyer, whose firm recently developed a smart-home community, Karma, in Phoenix.
“But the real value is in the increased occupant comfort, which directly translates to pride of ownership,” he says.
5 Passive Cooling Features to Know
Though passive cooling is easiest to implement in a new build, some features can be retrofitted to existing homes, according to Curt Johansen, development director for Triad Development, creators of Lagoon Valley, a sustainable community in Vacaville, Calif.
These five passive cooling features can attract buyers seeking future-proofed or sustainable homes. They’re also excellent considerations for homeowners who want to save on energy costs or prepare their homes for eventual resale.
1. Reflective White Paint on Exteriors
Using light colors to reflect sunlight is nothing new, but advances in research and technology could make ultra-reflective paint de rigueur in hot climates.
Last year, for example, scientists at Purdue University found that using ultra-white exterior paint could cool the home as efficiently as central air conditioning.
For homeowners who prefer to shy away from a stark white house, there’s still room to play. A white roof could be paired with colorful brick or siding. Roofing products with cooling color pigments can also reflect up to 60% of sunlight, according to the U.S. Department of Energy.
Researchers say these so-called “cool roofs” can reduce home temperatures by up to 5.4 degrees Fahrenheit. While that’s no substitute for air conditioning when temperatures soar into the upper 90s, it’s a viable start.
2. Clerestory Windows and Skylights
Heat rises, and one of the simplest passive cooling tricks is to give that heat an easy exit. That’s how operable clerestories—window rows placed above eye level—and skylights help keep homes cool without consuming energy. While adding windows is a costly renovation, it can enhance aesthetic and energy-saving value for homeowners whose existing home has high ceilings or large swathes of blank wall space.
Combining clerestory windows and skylights works by optimizing two types of airflow: cross-ventilation and stack ventilation. Operable clerestory windows placed across from each other in a room or house promote breezy cross-ventilation, explains Rempel.
“Stack ventilation relies on the principle that warm air rises,” explains Boyer. Eye-level and clerestory windows invite cool air into the home, pushing warm air upward and out through open skylights. Boyer says skylights have the added benefit of “allowing controlled natural light to brighten your interior spaces.”
While clerestories and skylights might attract some buyers for aesthetic reasons, real estate professionals can also educate budget-conscious buyers about the energy-saving value of these features.
3. Triple-Glazed Windows
Direct sunlight through windows is one of the greatest contributors to heat inside the house, according to Rempel. Anything that prevents this warming can help slash energy costs, especially in areas with little shade.
“[Replace] older windows with energy-efficient, triple-glazed windows, with operable shades, on all south- and west-facing walls,” Johansen says.
Brokers can play a key role in explaining how a listing’s triple-glazed windows can dial down energy costs and ultimately make the house a more comfortable home, especially in areas affected by heat waves or power outages.
4. Exterior Window Coverings
Because the sun’s rays quickly heat houses, Rempel says exterior operable shading is one of the most effective cost-cutting passive cooling features.
“This takes the form of operable shutters, awnings, screens or blinds exterior to the window,” she explains. “The shade can deflect the solar radiation before it even comes in through the window.”
To maximize energy savings, homeowners can opt for moveable exterior coverings. When temperatures cool in the evening, the shades should be retracted or opened “to let warm glass surfaces radiate to cold night skies,” Rempel says.
For sellers, attractive window coverings could also boost curb appeal.
5. Cooling Landscape Features
Lush landscaping can help cool a house in two ways: preventing sunlight from shining directly into rooms and, in the case of fountains or ponds, absorbing heat to cool the air.
Cities in the southern states significantly benefit from trees, says Rempel. “Leafy trees cool the sidewalk and streets under them,” she explains. “Tree shading also affects the light quality, creating a sense of coolness … even if the heat and humidity are unbearable.”
Of course, it’s key to keep humidity levels in mind. In hot, dry climates, a plant-filled indoor-outdoor space equipped with misters offers a comfortable extension of the home. Houses in humid climates such as Florida or Louisiana, on the other hand, benefit most from drying cross-breezes and shade. This is easiest to accomplish with a screened-in porch heavily shaded by trees and awnings.
Using landscaping like trees and high shrubbery to shield the home’s windows and roof—where possible and safe—from direct sun with landscaping features is great in humid and subtropical climates as well.
Translating the Value of Passive Cooling to Your Clients
Real estate professionals play a crucial role in explaining the value of passive cooling. Budget-conscious buyers abound, particularly in the current economic climate of high fuel costs. This passive cooling solution could give sellers an edge in a market that some say is tipping in buyers’ favor.
If you’re ready to help clients understand the benefits of passive cooling, you have three main angles:
- Passive cooling reduces energy costs. Passive cooling can reduce total air conditioner loads by up to 80 percent in milder climates and up to 30 percent in hotter regions, says Rempel. Southern homeowners might still need mechanical air conditioning, but the savings are more significant because baseline air conditioner usage is greater.
- Passive cooling boosts comfort. A house protected from solar heat during the day and cooled through natural ventilation at night “will be tens of degrees cooler during the peak hours,” Rempel says.
- Passive cooling is environmentally friendly. For home buyers who care about the environment, sustainability matters. More than half of REALTORS® report client interest in green home features.
- What’s important to remember, Johansen says, is that though passive cooling features aren’t always cheap, the long-term cost savings and comfort will be substantial.
“Good design is good business,” adds Boyer, “leading to positive buyer perception and increased return on a seller’s investment in their home.”
Reprinted from REALTOR® Magazine by permission of the National Association of REALTORS®. Copyright 2022. All rights reserved.