The oldest surviving part of the 12th century church is the Nave with its original North and South doorways, which are still in use today. On either side of these two doorways were single-light, round-headed windows, which have been blocked in at a later stage of the church's history, but remains can been seen from outside. An interesting survival from this early period is the 'Tympanum' (as of a drum skin, the surface between the lintel and the arch above it) set above both doorways. They usually depicted a Biblical scene and were obviously intended as visual reminders to churchgoers. The external arch of the north doorway is decorated with rosettes and saltire crosses.

Inside the church and turning towards the East window, you will see in the South wall a small stairway that led to a ROOD LOFT. In mediaeval times a large plank of timber (perhaps with a screen below it) stretched across the building, separating the main body of the church (the nave) from the chancel, where the choir and priest said Mass. On this timber (maybe even a walkway) was a "ROOD" (the ancient name for the Cross), probably with a figure of Christ on it. During the great Reformation of the 16th century, a new and simpler understanding of the Christian faith gained ascendancy in the Church of England. The Holy Communion was no longer seen as the sacrifice of the Mass to be conducted away from the gaze of the common people. IT IS THE LORD'S SUPPER - THE FELLOWSHIP MEAL OF THE WHOLE CHRISTIAN FAMILY. In 1550 the Bishop of London, Nicholas Ridley, ordered that all stone altars and Rood screens should be removed from the churches in his diocese, of which Chadwell was one. From that day the hole in the wall has remained there, a reminder that ours is a reformed and Protestant Church. In the 19th century an iron work screen was again erected to stretch across this part of the church, but this was removed in the extensive renovations in the 1970's. (A small oil painting of how the interior of the church used to look is kept in the vestry.)