St Mary's has a seven-bay aisled nave with arcades of c.1200, a 13thc. S chapel, and a 15thc. clerestorey. The chancel is 13thc. and the tower 14thc. with an octagonal ashlar spire. Construction is of roughly coursed stone. The nave has N and S doorways, the S giving access to a hexagonal meeting room, built in 1985 and extended in 1999, while the N, under a 14thc. porch, is an elaborate composition contemporary with the nave arcades.

A church of St Mary existed in 1109, but the present building dates from the time of Bishop Eustace (1198–1220).

The N doorway and arcades belong to Bishop Eustace's campaign. Stylistically the S arcade comes first, then the N with its greater variety of scallop forms and finally the doorway with stiff-leaf and dogtooth.