Barnston is a village in the west of Essex, 2 miles S of Great Dunmow and 9 miles NW of Chelmsford. The old village centre, around the church and Hall, is half a mile E of the compact, modern settlement. The church consists of a 12thc nave with a timber bell turret, probably 18thc, at the W end and a S doorway without a porch. This is 12thc as are two round-headed lancets in the N wall, one blocked. The chancel has no details earlier than the 13thc. The exterior walls are rendered. Repairs undertaken in 1967-71 included the digging of a shingle-filled drain around the walls, but clearly this was not entirely successful as work was being undertaken on the drainage system in 1998. The S doorway is the only Romanesque feature described here.

Barnston was held in 1066 by Wulfwine as a manor of 2 hides and 30 acres, and in 1086 by Hugh de Hugh de Bernières from Geoffrey de Mandeville. The manor also included woodland for 200 pigs and 20 acres of meadow.

Only the outer order of the doorway is original, although the jambs might contain some 12thc stonework. The capitals and imposts suggest a date c.1140-50. Rodwell records that the cement on the walls was recently replaced ( ). At the time of the visit some of this and the whitewash was flaking off in places and repairs were being carried out. Rodwell also mentions that repairs undertaken in 1967-71 included the digging of a shingle-filled drain around the walls. Work was being undertaken on the drainage system at the time of the visit in 1998.

RCHME (1921), Pevsner (1954) and the EH listing (dated 1967) describe the dedication as unknown. The dedication to St Andrew postdates 1999, but was in place by 2007 (Bettley and Pevsner).