Those who permitted that

Humayd says: Sayyiduna Anas (may Allah be pleased with him) used to pray the Friday prayer with the imam in the house of Nafi' bin Abd al-Harith. That house was slightly elevated above the mosque, and one of its doors opened into the mosque. He would pray the Friday prayer in that house, following the imam.

Salih, the freedman of al-Taw'amah, says: I prayed with Sayyiduna Abu Hurayrah (may Allah be pleased with him) on top of the mosque, following the imam, while the imam was below.

Abu Mijlaz says: If a woman prays behind the imam in such a way that there is a wall between the two of them, then if she can hear his takbirs, this following (of the imam) is valid.

Sa'id bin Muslim says: I saw Salim bin Abdullah pray the Maghrib prayer on top of the mosque. There was another man with him, and they were following the imam.

Mansur says: To the right side of our mosque, lower than the imam, there was a rooftop. During the days of al-Hajjaj's rule, some people who were in hiding used to pray on that rooftop and follow the imam, even though there was a long wall between them and the mosque. I mentioned this to Ibrahim and he considered it good.

Ibn Awn says: Muhammad (Ibn Sirin) was asked: If a man stands on the roof of a house in Ramadan and follows the imam, is there any harm in it? He said: I do not see any harm in it; however, he should not be ahead of the imam.

Hisham bin Urwah says: Urwah used to pray following the imam while he was in the house of Humayd bin Abd al-Rahman bin al-Harith, even though there was a road between him and the mosque.