Paterfamilias was the oldest living male in the household and he held power over the rest of the family. Every important decision was made by the paterfamilias.
"Ubi est paterfamilias?" "Est paterfamilias." "Ubi?" "Est." "Non scio." This just feels awkward to me. There's no actual definition of where the paterfamilias is, so adding a specifier in English feels off.