Meantime the rebuilding went on rapidly; in a few cases a street was widened; but the narrow lanes running north and south of Thames Street show that little regard was paid to the regulations. No wooden houses were built, and the old plan of high gables and projecting windows was exchanged for a flat façade and square coping. The churches were rebuilt, for the most part slowly. Some were not rebuilt at all. The last was finished thirty years after the Fire. Of the general character of Wren’s churches this is not the place for an estimate. It is sufficient here to explain that Wren was guided first by the sum of money at his disposal, and next by the extent of ground; that many of the old churches were quite small buildings standing in small churchyards; but he extended the foundations and increased the area of the church; that he built in every case a preaching-house and not a mass-house, so that nearly all the churches are oblong halls instead of cruciform buildings; that he studied the interior instead of the exterior, and that some of his finest churches inside present no feature of interest on the outside. The builders, all over the City, used as much as possible of the old foundations. Thus the Heralds’ College preserves the court of Derby House; Wardrobe Square is the inner court of the King’s Wardrobe Palace; while the narrow streets on either side of Cheapside preserve exactly the old lines of the streets burned down. It would be interesting to ascertain, if possible, where Wren’s churches were built upon the older foundations; the north wall of the Holy Trinity Minories, for instance, belongs to the ancient convent there; the vestry of Allhallows in the Wall is on a bastion of the wall.