Isuspect that our species has been longing for “smart homes” since prehistoric times. John Q. Caveman is in one corner of his cave, about to retire after a long day of gathering (he’s never been the hunting type), and suddenly, a needling worry becomes lodged in his mind: Did he put out the fire in front of the cave? He vaguely remembers doing so, but what if he’s thinking of last night, not tonight?

Millennia later, we are caught in the same fix. Do you drag yourself out of bed and down two flights of stairs to check if you turned off the space heater in the basement? Home automation was supposed to have solved this. For decades, technology companies and futurist magazines have teased us with visions of houses in which the lighting, temperature, TV and audio system could be controlled from a central unit. You are supposed to be able to check on that basement heater while staying snug under the blanket.

But while much of the necessary technology exists, easy-to-use smart-home systems have always been the province of the ultra-wealthy. Economical DIY alternatives for the rest of us, including partial home-automation devices like universal remotes for entertainment systems and devices that control appliances remotely, have largely fallen short of the home-automation dream.

The good news is that the prices on that other route to a smart home, customized systems installed by professionals, are slowly starting to fall. Some upper-middle-income people may already be able to afford a professionally designed setup that controls at least a complete entertainment system, or maybe one that controls a few items like the TV, the lights, the thermostat, the door locks and, say, the coffee maker, while others may be able to afford them soon.

Randy Stearns, the president of Engineered Environments, a Bay Area company that sells professionally designed automation systems, showed me one of his smaller projects, the automation of an entertainment system for Bill Weeks, a retired real estate executive who lives near San Francisco.

Weeks’ wall-mounted TV was connected to a rack of other audiovisual equipment in a nook carved out of a nearby stairwell. There were no visible wires; all the connections were hidden behind a wall panel. Weeks could control his entire system with a single remote that had been configured to his specifications by one of Stearns’ technicians.

When I have tested store-bought universal remote controls, they typically get out of sync with the equipment, or lack certain crucial buttons, and inevitably I needed to reach for the original remotes to be able to get everything under control. But the remote that Stearns’ firm provided as part of Weeks’ system (URC’s MX-980, a complex device usually sold to and configured by professional installers) did not suffer from those flaws. Its buttons and on-screen panel could be endlessly programmed to do exactly what a user wanted. When Weeks pressed “Watch DVD,” for instance, his TV and his DVD player sprang into action. Weeks said he had never had to explain how to use the TV, not even to baby sitters or grandparents.

“We wanted to make it obvious for everyone who came by,” he said. He had to pay a fortune for that simplicity, though. The total cost of Weeks’ configuration, including equipment and installation, was $4,600, in addition to the television he bought separately.

Weeks’ bill is representative of current prices; professionally installed smart-home systems run from a few thousand to tens or even hundreds of thousands of dollars, depending on the scope of the job. But Dave Pedigo, senior director of technology for the Custom Electronic Design and Installation Association, a trade group of home theater and home automation installers, said that prices for custom automation kept falling, and that one major reason was the advent of touch-screen devices like the iPhone and iPad.

“The onslaught of Apple and Google devices has really been changing this market,” Pedigo said. To illustrate Pedigo’s point, and to give me a taste of what less-affluent homeowners might be able to enjoy in coming years, Stearns took me to a sprawling house in the Bay Area suburb of Atherton, where his firm had installed an extensive home-automation system. It included over a dozen TVs, among them a 262-centimeter screen in a dedicated home cinema, as well as a whole-home audio system, with speakers mounted invisibly in the ceiling. There was also an integrated lighting and climate-control system, so that the family could, say, keep tabs on the temperature in the wine cellar while working out in the home gym, on the other side of the property.