South aisle, mid C14, three 3-light windows with reticulated tracery similar west window, ashlar parapet, single pitched roof
Gabled buttresses at corners with gargoyles
2-stage angle buttresses, west door with 4-centred head: tall C14 three light windows immediately above with panel tracery
Interior: 6-bay C14 arcade with octagonal piers and double chamfered arches: South taller with concave sides to piers, stained glass: east window by Morris and Co
South window of chancel has remains of glass c1532
North chapel C19 glass by Ward
Monuments: Inscribed tablets to Robert Washington 1622 and Laurence Washington 1616 in nave and chancel respectively
south-east corner by John Stone, demi-figure rising from urn
John Spencer 1783, by Nollekens, west of bay window is white marble tablet, female figure with male profile in clouds
The Spencer chapel is scheduled as an Ancient Monument. (Buildings of England: Northamptonshire, p.229)