1 Let us now consider, so far as indicated by the evangelist John, what was done with, or in regard to, our Lord Jesus Christ, when brought before Pontius Pilate the governor. For he returns to the place of his narrative where he had left it, to explain the denial of Peter. He had already, you know, said, “And Annas sent Him bound unto Caiaphas the high priest:” and having returned from where he had dismissed Peter as he was warming himself at the fire in the hall, after completing the whole of his denial, which was thrice repeated, he says, “Then they bring Jesus unto Caiaphas into the hall of judgment (pretorium);” for he had said that He was sent to Caiaphas by his colleague and father-in-law Annas.
But if to Caiaphas, why into the hall of judgment? Nothing else is thereby meant to be understood than the place where Pilate the governor dwelt. And therefore, either for some urgent reason Caiaphas had proceeded from the house of Annas, where both had met to give Jesus a hearing, to the governor's pretorium, and had left the hearing of Jesus to his father-in-law; or Pilate had made his pretorium in the house of Caiaphas, which was so large as to contain separate apartments for its own master, and the like for the judge.
Source: Tractates on the Gospel of John (New Advent)