The archaeological work has identified the fourteenth century foundations of the nave which have been repaired, almost certainly during the restoration of 1862 when the west end of the church was rebuilt.

In the east end of the trench the ironstone and sandstone rubble foundations for the gable wall were encountered. The very top of the foundations incorporated handmade brick fragments measuring 4 ⅝ x 2 ¼ inches thick which were probably used to level or strengthen the foundation during the rebuilding of 1862. Above was a mix of coursed ironstone and limestone, which supported the ashlar masonry above. Both ironstone/limestone and foundations were bonded with brown sandy clay. The foundations had been truncated by a modern service trench infilled with a fill comprising limestone and ironstone rubble, the remnants of the foundations, in a matrix of loose dark grey silty clay loam, re-deposited grave earth. One trench had in turn been truncated by the insertion of a concrete bedding layer for a surface drain.

Matt Hurford, 2019, Church of St Giles, Costock, Nottinghamshire: Archaeological Recording of Groundworks within the Churchyard (Unpublished document). SNT6131.