YOU SAID:

The custom is to be sad in a house

INTO JAPANESE

習慣は家で悲しむことです

BACK INTO ENGLISH

The custom is to grieve at home

INTO JAPANESE

自宅で悲しむのが習慣

BACK INTO ENGLISH

It is customary to grieve at home

INTO JAPANESE

家で悲しむのが通例

BACK INTO ENGLISH

It is customary to grieve at home