In houses and in synagogues

Several modern writers have boldly asserted that every New Testament church was a house church. From the life of Saul (later called Paul) we notice that he looked for Christians both in houses and in synagogues.

Acts 8:3 As for Saul, he made havock of the church, entering into every house, and haling men and women committed them to prison.

Acts 9:1-2 And Saul, yet breathing out threatenings and slaughter against the disciples of the Lord, went unto the high priest. And desired of him letters to Damascus to the synagogues, that if he found any of this way, whether they were men or women, he might bring them bound unto Jerusalem.

I've read that there were hundreds of synagogues in Rome alone. The requirements to establish one did not require a large number. Conceivably an entire synagogue could have "crossed over" as thousands of Jews and even priests discovered their Messiah.

Acts 6:7 And the word of God increased; and the number of the disciples multiplied in Jerusalem greatly; and a great company of the priests were obedient to the faith.

I am not a greek scholar or a historian but I do appreciate them very much. Anyone done any research on this interesting subject?