Cortana, Microsoft’s vocal virtual assistant, is gaining the ability to control smart-home products like lights and thermostats.

Home-automation company Insteon, based in Irvine, California, is working on a Windows Phone 8.1 app slated for release later this year that aims to make it easier to do things such as turn on the lights or boost the temperature by issuing commands via Cortana like, “Insteon, turn off all the lights” or “Insteon, adjust living room thermostat temperature down.”

Cortana, which was announced in April and is built into Microsoft’s Windows Phone 8.1 (which began rolling out to Windows Phone 8 users on Tuesday), can answer spoken queries like “What’s the traffic like on my way to work?” and respond to commands like “Change my 10 a.m. meeting to 11” or “Remind me to feed the cat when I get home” (see “Say Hello to Microsoft’s Answer to Siri”).

In many respects, it’s very similar to Google Now and Apple’s Siri, but unlike these competitors, Microsoft is allowing third-party developers to create apps that can be controlled using Cortana—a move that could inspire app developers to dream up new uses for the voice interface.

In addition to its iOS and Android apps, Insteon already offers conventional apps that allow users to control the company’s Internet-connected lightbulbs, wall switches, thermostats, and outlets on Windows phones and tablets.

The addition of Cortana voice controls is still in the early stages. During a demonstration at a Microsoft Store in San Francisco on Tuesday with a Windows smartphone and array of Insteon gadgets, it could do only a few simple things like turn an Insteon lightbulb on and off or, in response to the spoken command, “Insteon, it’s hot in here.” The smartphone responded “Nobody likes being hot, want to adjust your thermostat?” while pulling up thermostat information.

Insteon cofounder and CEO Joe Dada said in an interview Tuesday that he has long been interested in bringing voice control to his company’s automation products. Yet while Insteon has tried voice-recognition technologies in the past, it found consumers weren’t interested enough and the technologies didn’t work well enough. “It was just too early,” he said.

Dada says he’s currently using Cortana at home to turn various things on and off.

Despite efforts to improve understanding of voices and language and filtering of background noise, though, usage of voice-recognition technology is still not all that common. Consumers expect voice-recognition software to work nearly all the time, and often get frustrated when it fails—which is still a common problem no matter which company is behind it.