Hauxton has kept its 12thc. aisleless nave and chancel, and the chancel arch between them. The nave terminates at the E end with angle-rolled buttresses. The chancel had an apse originally but is now square-ended. Transepts were added to the nave, but have been removed. The W tower, with its tower arch, is plain Perpendicular. A storeroom has been added to the nave, approached from within through the completely plain N doorway. Construction is of flint and pebble rubble with render on the chancel. 12thc. carved features are the S doorway, one nave window, the chancel arch and possibly the font.

The S doorway, windows and chancel arch are presumably original to the building and must date from c.1100. The chancel arch arrangement with paired half columns and a second-order nook shaft also occurs at Isleham Priory, although the forms of the cushion capitals differ. Johnson notes that the E capital of the doorway has a close parallel on the S doorway of St Mary Magdalene's chapel, Cambridge. The chip-carved lintel is comparable to work at Little Abington, and the quatrefoil diapering of the window head is the same as work on window heads at Little Abington and St Mary Magdalene's, Cambridge. She suggests that the same local or itinerant workshop was responsible for both Hauxton and St Mary Magdalene's.