In the 13th century a clerestory with six Early English lancet windows on each side was added to the nave to increase the amount of natural light, much of which had been lost when the aisles were added. Another Early English lancet window from this period survives in the north wall of the chancel. The south aisle proved to be unstable and was underbuilt in an attempt to stabilise it. At a later date, it is not known in which century, the south aisle was demolished.