The contrast between the earlier west end and the later east end is readily apparent from the outside. The nave of Kentish ragstone in an early gothic style with its large gable end and belfry belongs to the original building of 1858 by Morphew and Green. Pevsner, in his ‘Buildings of England’, described it as “a cheap church” and no doubt the plan to build a chapel of ease for the inhabitants of the poorer part of Sevenoaks called for simplicity of design. The north aisle was added in the same style in 1878.
The east end of 1901-05, consisting of a new chancel, a Lady Chapel and the first bay of what was intended to be a new south aisle, is altogether grander. It is constructed of brick, with a higher roofline and more elaborate window tracery. With the coming of the First World War, plans to rebuild the whole church in this style were abandoned, although a chancel bellcote was added in 1939. St John’s therefore remains to this day very obviously a hybrid of these two stages in its development.