We don't use Home & Away Routines. But I suspect the only way to do what you want to do would be to add your housemate to your Google Nest household, and then set up Home & Away routines to turn OFF camera alerts when EITHER of you are home and turn on alerts when BOTH of you are away. (You can't turn alerts on or off for just one of you.) You should be aware that some customers report that the Home & Away feature doesn't always accurately detect when you're home or away.
Hi and thanks for the feedback,after some further sherlock holmes work we figured it out, you have to have any additional members to the families phone location services set to always on..i couldnt see that explained anywhere at the start of the mission it would of helped but all sorted now. Thanks
Thanks for posting. I've seen that this post has reached its resolution. Thanks to everyone who collaborated on this thread especially @MplsCustomer and @pablo1eye. Since this has been resolved, we'll consider this as complete and will lock the thread in 24 hours. Feel free to start a new one if you need assistance with your Google Nest devices and the Community would gladly help.