The walls at the base are 9 feet thick, and about 7 feet at the summit. The building is of three stages, a basement, at the ground level, 12 feet high; a first floor, 25 feet; and a second floor rather more, perhaps 30 feet. The floors were of timber. The first floor seems to have rested on a ledge, the upper and the flat roof upon joists, those of the lower lying east and west; those of the upper, north and south. The joist holes in the north wall have been closed by early work, and above is a slight set-off or shelf in the wall, as though the level of the floor had been altered. In the west wall, also, new joist holes, smaller, have been cut above the old ones. The original roof was very steep, having two slopes and a central gutter, as at Porchester, and the reverse of the arrangement at Ludlow, where the ridge was central, and the two gutters lateral. The weather table remains perfect in the north wall, with a hole 2 feet high by 1 foot broad, to carry the beam which supported the gutter and the feet of the rafters. The table is seen continued horizontally upon the west wall, where it was laid as a flashing to cover the upper edge of the tiling. The walls were brought up to a level line all round, so as to conceal the roof. This arrangement, as at Ludlow, Richmond, Porchester, and the gatehouse of Sherborne, shows that there was no original intention of using the roof as a platform for mangonels and such like heavy machines. The flat roof, of lead, was apparently of later introduction. No traces remain of any mural staircase in the north or west wall, nor of any mural passages. The basement was, probably, a dark store or cellar, reached only by a trap in the floor above. The entrance seems to have been on the first floor in the west wall, in which also are traces of a loop or small window. The north wall remains perfect. It was most exposed, and is without openings of any kind. In what remains of the south wall is one jamb of an original fireplace, of which is seen the sloping back, and part of a lateral nook and Norman abacus above it. The flanking shaft is gone. In the part of the east wall still remaining is the northern half of a small full-centred window, deeply splayed inwardly. The east and south walls above the first floor are gone. In the west wall, upper floor, is seen the north jamb of a small full-centred window set in a bold splay of hourglass section. North of it, in the same wall, is a small recess, probably for a lamp, and which seems to have been round headed. There, probably, was a fireplace in the south wall.