I don't think there is no value at all, there are already lots of house robots for sale - robotic vacuum cleaners, lawn mowers, floor cleaning robots etc. Just take iRobot products - Roomba or Scooba, they are pretty popular already. And it is surely gonna be better in the future.
To compare, "home robots" have only a little bit more searches, 14,800.
And the owner of homerobots.com wants $25,000 for his domain.
Edit: and houserobots.com is listed for $4,188.
There must be some value in .net, if you take future growth into account, or not ?