For this church:
The current fabric of St John’s is essentially from three periods of building spaced over 800 years. The first period is approximately 1070 to 1200, the next, the second quarter of the 15th century, and the third in the first half of the 19th century.
The oldest part is the lower walls of the tower, built of coursed rubble-stone and including herring-bone work, with two-light round headed windows and no plinth. This dates from probably pre-1070 and has clear butt joints onto the enlarged nave.
This enlargement, from 1070-1100, is clearly wider than the tower with long and short quoins both to north and south at the west end. The nave north wall from this period is clearly marked by a change from its coursed rubble-stone to later ashlar blocks, the line of which runs through the clerestory windows. Internally, above the north arcade a clearly defined ridge halfway up the clerestory windows corresponds with the external evidence.
From the same period is the chancel, also of coursed rubble-stone with no plinth and ashlar quoins in the north east corner. It probably had three small windows on the north side. Evidence for this is, externally, a redundant small round headed window with an arch cut from a single stone, and internally two narrow round headed windows that now open into the Becket Chapel.
The north arcade, the east wall of the north aisle and, probably, the arch through to the tower are from the next building phase of 1135 to 1154, but interior plaster work has hidden any evidence of joints.
The final construction work of this first building period was the Becket Chapel. Externally the coursed rubblestone east wall is butt-jointed to the chancel. There is a redundant lancet-shaped window with small voussoirs set very high up, and internally, the arch opening into the chapel from the chancel cuts into the two small windows already mentioned.
The second phase of building lasted a relatively short time in the 15th century, but involved a number of major changes to the fabric.
The tower was raised a further storey and this is clearly marked by a change from the rubble-stone work to smooth ashlar blocks. To support the additional stress of this, and the building of an internal staircase, buttresses of smooth ashlar blocks were added. That to the south west corner is keyed into the tower fabric and is slightly larger because of the stair, whereas the others are butt-jointed.
Buttresses were also butt-jointed onto the south east corner of the chancel and also halfway along the chancel south wall. The window on this wall, with three cinquefoil lights, dates from this time, as does the present east window and the window in the wall of the tower.
Another significant change was the addition of the clerestory windows. On the north side four courses of smooth ashlar blocks from halfway up the windows show where the wall was raised to accommodate them.
The last change was the rebuilding of the chancel arch with an opening in the north side, possibly where a stair to a rood was sited.
The third phase of building was that of the 19th century. In this the north aisle was rebuilt to make it wider. Externally very clear butt joints can be seen at the west end between the 11th century work and the smooth ashlar of the 19th century. At the east end it is less clear. The Becket Chapel was rebuilt, but the east wall shows what appear to be two phases of enlargement, that of the 19th century and an earlier one. Both are shown by butt jointing but also a string course broken by the earlier jointing. The window is a later insertion with a crude head that appears to be from other mouldings. It is possible that it is stone redundant from the chancel east window when that was enlarged in the 15th century. There is also a small pilaster that has been placed under this larger window. Internally, the wall between chapel and aisle appears to have been thickened as the arch is quite deeply recessed by plasterwork that partly covers the stonework on the left.
The Norman door in the tower was placed here when the south aisle, vestry and porch were built. The butt jointing at the west end is very clear, as is that where the small porch butts onto the chancel buttress.
One final change in the fabric that can be seen, is where the roof of the nave was raised in 1939. This is shown by the courses of smaller stone blocks at the top of the north and south nave walls.