CHIBA, Japan -- Startups that make green homes be warned: Panasonic is coming. It will take a few years, but it's coming.

The Japanese electronics giant has assembled a strategic plan to start making modular homes in about three to five years that will combine green construction along with sophisticated electronics to curb energy consumption, according to executives during a roundtable discussion at Ceatec, a large technology trade show taking place near Tokyo this week.

In a Panasonic demo at the show, sensors embedded in the ceiling adjust the air conditioner and lights depending on whether or not people are present. The sensor system (based around a technology called Beam Steering) also tries to determine which members of the household are in the room. If grandpa is there, for example, the heater might get cranked up.

"House to total solution, Panasonic is the only company to propose that," said Ohtsubo Fumio, president of Matsushita Electric, which will officially change its name on a global scale to Panasonic on October 1.

Read more at Green Light.