The surviving medieval work is mostly in Dundry stone from Somerset, with some local blue lias and Sutton stone, Purbeck marble being also used internally. The post-Reformation work is in lias, and Chipping Camden and Bath limestones with a little red Radyr sandstone in the Chapter House. The post WWII work is in concrete, faced with glacial pebbles and Pennant sandstone. The roofs are of Welsh slates and lead, almost all replaced post-WWII bomb damage.
The plan is nave, with north and south aisles and paired west towers, choir within the nave, sanctuary with ambulatory, Lady Chapel, partly within the main body of the church, Chapter House on the south, St. David's Chapel on the north and this is joined via the Processional Way to the Prebendal House (qv).
The West front, with its gabled end to the nave, is Early English, flanked on the left by the almost entirely Perpendicular north-west or Jasper Tower and to the right by the almost entirely Victorian south-west tower. The ground stage has a large central doorway, although this is well above the nave floor level (see Interior). Arched head with continuous chamfer outline, colonnettes and dripmould. Double lobed head to door with carved bishop in the key. Triple arched stage above, higher in the centre and with tight blind arches between. Above in the gable is a stepped arcade with central window and a trefoil headed niche above. Cross to gable. To the right is the south-west tower stair-turret with slits and a continuous mould. All this in the 'West Country' style as also seen in Wales at Llantony Priory (qv Crucorney Community, Monmouthshire). Three stage north-west tower with full height stepped buttresses, strings and octagonal stair-turret. The buttresses were said to have been 'added in modern times' in 1842 and thus may have been added by Wood in c1735 to strengthen the tower following the major collapse in 1722; there is a print made prior to the damage which shows the tower without buttresses, while post damage ones show them in place. The ground stage has a 3-light Victorian window, above, on each face, are a 2-light and then a 3-light window, which repeat from the ground stage, but these are late C15. The then existing battlemented parapet ('a mean and modern battlement', 1842) was replaced by an elaborate filigree crown of the Somerset type (e.g. St. Stephen, Bristol; but it is also modelled on St. John's, Cardiff) by John Prichard. The battlements had replaced a similar crown following the storm damage in 1703. The south-west tower also has three stages but is Early English in character with gabled niches on the buttresses. Two-light windows to each stage, on all faces on the top stage. Corbel table to pierced finialled parapet, tall stone spire with corner pinnacles and with lucarnes on the main faces at the base.
The S side of the nave is eight bays separated by stepped buttresses. The aisle windows are 3-light with reticulated heads. The second bay from the left has the Norman south door with four recessed orders and much dog-toothing and zig-zags. Timber lattice outer doors with plank door behind. The clerestorey has large paired lancets with strip pilasters between and a corbel table above; all this invented by Prichard and Seddon from the limited evidence available. The S door is possibly reset, but it is not known when or from where. It remains directly opposite the north door in the proper Norman relationship, but it would be surprising if the Norman Cathedral was as large as that suggests. Both doors were, however, recorded in their present positions in 1842, before the Victorian restoration. ''On the south side all is in ruins to the fifth compartment of the nave and its aisle--from thence to the chapter house the aisle is entire... Though the south porch is gone, the door-way which it covered is still perfect, and is a most beautiful example of the richest Norman work.'' (Winkle 1842) All the features on this side were damaged by bomb blast in 1941 and repaired soon after WWII. Very steeply pitched roof above, much more so than previous to 1703. This treatment is repeated on the north side of the nave except that the second and third bays are largely covered by St. David's Chapel, see below; while the Norman N door is now entirely an internal feature (see Interior).
The Sanctuary is two bays and is clearly of an earlier date and character although evidence of the Norman Church survives only internally. The aisle windows are a continuation of the north aisle ones, with 2-light windows in the clerestorey above. The exception is in the south aisle wall, next to the Chapter House, where there is a 5-light window with segmental head and reticulated tracery, and also an arched doorway into the aisle beside it, this last is Victorian. Roundel in the east gable wall above the roof of the Lady Chapel. Gable verges and apex cross, the roofline is carried through from the nave and the roof structure is wholly Prichard and post WWII when the chancel arch was lowered and the external division of the roof removed.
The first bay of the Sanctuary on the S side is covered by the Chapter House. This is square going to octagonal but the upper floor and the characteristic pointed roof were entirely reconstructed in c1850 and again after bomb damage in c1950. It is built of rubble stone with corner buttresses, lancet windows, some paired on the upper storey and a bell-cast roof. This last is a post WWII feature as the entire roof structure was removed by the bomb.
The east end has a 3-light window in each aisle and then the projecting three bay Lady Chapel. This has a large 5-light window with Geometric tracery in the east end, the first thing restored by Prichard and dating from c1844. The side walls have three 2-light windows with trefoil heads. C15 type low pitch roof with battlemented parapets and corner pinnacles, although this was actually a Prichard alteration made necessary by his heightening of the Sanctuary.
The final external feature is St. David's Chapel dating from 1953-6 and designed by George Pace. This covers the second and third bays of the N side of the nave (see above) and projects to an unlit apsed end for the altar. The E wall has continuous glazing at high level, descending to low level as well at the altar end. The W wall has full height glazing. All is divided into narrow lights with concrete mullions and occasional transoms. Smoothly faced parapets above rubble walling, hidden roof. The chapel is reached through the Norman N door of the Cathedral and is part of the Processional Way which continues to the Prebendal House (qv).