[Ger-Poland-Volhynia] Catholic Church Records

[gpvjem]

    I have some extracts from Catholic records from Ozorkow in which a number appears beside the event, probably the registration number, however in the birth entries there is another number mentioned and it is refered as "Haus Nr. _ _ "   This number is found only in birth entries and not to marriage or death. 
    Can someone enlighten me please as to what this Haus Nr pertains to?

Thank you for any help,

John Marsch