The massive late medieval tower, which dominates the building dates from the late 15th or early 16th century; it was erected at a time when many other churches in the region were also being provided with new or renovated west towers. Emley's tower was entirely new; it is built of large , neatly dressed gritstone blocks and has been little altered since. The tower probably replaced a small bell-cote, set between two windows on the west wall of the nave. The side of one of these windows can still beseen within the church, by turning to the left just insiode the doorway.
The rest of the church underwent numerous additions, alterations and rebuildings at various times. Many important changes can be seen in the south walls of the nave and chancel, shown below. The nave wall was probably built in the 14th or early 15th century; but the rough, uneven stonework and the scattered blocks of the Norman masonry show that it is largely made up of material salvaged from an even earlier church. The windows are 19th century restorations, but they are in fact set within the rectangular frames of older windows; the top of the earlier window on the left can be seen just below the roof eaves.
The roof of the chancel has also been changed considerably: the scar of an earlier, more steeply-pithced roof can be seen in the gable wall of the nave. The core of the chancel wall was built at the same time as the nave; a narrow band of the original walling can still be seen at the junction of the nave and chancel. Later the chancel was refaced, and took on its present appearence. The large, neat gritstone blocks and mouldings on the plinth and buttress - more elaborate than on the nave - are reminiscent of those on the tower. The chancel was probably refaced either at the same time as the tower was built, or soon afterwards. Its windows are in a style of belonging to the late 15th century.