Nest thermostat in Two buildings

[MichaelBarsott]

I have one nest in the main house where my wife and I live, her father lives in our detached carriage house. If I put a second nest under my account in his apartment will it detect when he's gone and use eco mode, even though I'm home.

[sporfrog]

Because they are separate buildings and you consider the carriage house an apartment, I would recommend using two homes. In the Google Home app you can configure more than one home.  Each home can have it's own home/away status.

Google Home -> + icon (upper left) -> create new home.

For each home configure Home/Away and presence sensing. For your home, you and your wife and other household member's phones will participate. In the carriage house only your father-in-law's phone will participate or you can use only the thermostat sensor.

[cmbarsotti]

Thank you.