Thaumas P. Ehr, Landscape Architect

Early Arizonans knew how to stay Cool Naturally

 If you had to live a week without air conditioning this summer, do you think you would survive?


If you’ve set up your home to take advantage of natural breezes and to block the hot sun, you’d have a pretty good chance. After all, generations of Arizonians managed to get through summer after sweltering Arizona summer without mechanical intervention before air conditioning as we know it hit the market in the early 1900s and came into common use in the ’50s.


We can learn a lot about smart housing from history. In fact, our forebears can teach us a few things about saving energy and spending a whole lot less to stay comfortable at home.


Some of Arizona’s earliest Indian cultures built their homes from the earth on top of deep pits or into the sides of caves. They relied on the ground’s natural coolness to keep the indoors temperate. That concept translates into the modern basement—which few homes in Arizona have.


But a basement can prove valuable to an Arizona homeowner. Because it’s encased in earth, a basement stays super-cool during the summer, making it a great bonus room for your family.


From those early Indians to the 18th- and 19th-century Spanish and Mexican settlers, resourceful early Arizonians faced their homes to the south so in the summer, when the sun is high, their buildings were shaded.

Many of them built courtyard-style houses—often made from thick, adobe walls that slowed heat transfer into the home—forming a U or an L around an enclosed yard. The yard was equipped with a fountain and lush greenery so air that blew through would catch some cool humidity on its way into the house.


You can do the same by fencing in your backyard or, if you’ve been planning to add a garage or a sun room, by positioning it so it gives your house an “L” shape. Add a waterfall, mister or fountain and lots of native plants to achieve a similar cooling effect.


Also, if you have or add a porch on the south side of your house, take your color cues from the 18th-century, when desert dwellers whitewashed the walls of the house only halfway up and then switched to a dark color on top. The reason: When the sun was low at noon during the winter, it would hit the dark part of the wall, which would absorb the heat and warm up the house. In the summer when the early afternoon sun was high and hot, it would be blocked by the roof of the porch.


Today, south-facing homes still are the most comfortable. Still, if you live in a home that faces a different direction, you can add awnings and sunscreens to south-facing windows. Those awnings can reduce solar heat gain in the summer by 65 percent or more. Add awnings to west-facing windows as well to block the afternoon sun.


The south side is the best place for a porch, but the roof runs a close second. Nobody sleeps on the roof anymore, but it was common during territorial times because it was cool up there overnight.

Wherever your porch is, do what late 19th- and early 20th- century Arizonians did, and leave it open on three sides or surround it with big windows. Hang slatted window coverings or sun screens that keep out the sun but let the breezes in.


And if you’re in the market for new windows, consider replacing your sliders with double-hung models—they open both from the top down and the bottom up. In pre-a/c days, homeowners would open the bottom of the windows on one side of the house to let fresh air in, and open the tops on the other side to let hot air—which rises—out.


From mud huts to tract homes, the best strategies for beating the heat haven’t changed much—but we tend to ignore them because it’s so easy to crank the a/c a little lower. Relying more on cross-ventilation, good window shades, light-colored paint, strategically placed water features and trees, and other commonsense cool-downs worked for centuries.


For one week this summer, try relying less on your air conditioner. You may find yourself making changes around the house that you’ll stick with long after the summer!