1) Super-insulate the envelope of any building.
"Insulation is fractionally expensive and completely economical," Sander says. "When you're making thicker walls, the labor is pretty much the same if you’re doing wood frame." His Palm Springs design features 17-inch walls, filled with layers of foam insulation, structural insulated panels (SIPs), and a thermal blanket. With thick walls, "all of the other systems that you put inside the house don’t have to do as much work," and bills go way down, he says.
2) Create shade.
In addition to active shading methods—roll-down shades for interiors or exteriors—Sander advocates for passive shading. In the Palm Springs project, he added a 20-foot overhang to protect an entirely glass facade. "You can add to the outside of a building relatively easily," he says.
3) Pick good windows.
Sander swears by double- or triple-glazed windows. Adding tinting to windows that face the sun can be helpful in deflecting heat.
4) Don't discount simple tricks.
Heating a pool can be a huge energy suck—but a simple coat of paint helps mitigate the damage. "If you paint the pool darker, it retains more of the sun’s energy and heats the water," Sander says.
5) Consider solar.
"Solar-thermal is entirely off the grid." Sander says. "I love the fact that you can do things that are sensitive to your local environment and make living and owning a house easier." In sunny Palm Springs, an array of solar panels on the roof also helps heat the pool.