The south doorway is Norman, with traditional Norman carving decoration. There are fragments of medieval carving incorporated in the south porch, including shears, a cross, and a head within a quatrefoil design.
To that 13th century building were later added very fine Perpendicular features, including large, traceried windows, a slender west tower, and a clerestory heightening of the nave. The font and rood screen are also 15th-century features.
There are some features of historic interest, including a series of memorials spanning many centuries. Among these is a 17th-century memorial brass to John Mauleverer. The most interesting feature is a wonderfully decorated stone coffin lid thought to date to 1300. The coffin is beautifully carved with foliage twining around a cross.
St John's is no longer in regular use for worship and is in the care of the Churches Conservation Trust.