An old trick I've heard is to have someone call the house's landline while you are robbing it. As long as the phone is ringing, you can be reasonably sure that no one is home.
If it has an automatic answering system, you can't "let it ring for minutes", and if it has the ringer turned off (and there are lots of people who, with an answering, do this by default) then it won't even ring at all (though you'll think it is ringing.)
VoIP# -> unpublished home line (+ Mobile)
Home line 'protected' from autodialers by old fax machine, 4 rings then silence. Only political calls seem undeterred.