Cruciform in shape, the plan of the present building was completed by the end of the fourteenth century and has remained largely unchanged for the last 600 years.
St. Helen’s is built of flint rubble, or Totternhoe clunch, with flint facings and limestone dressings. There being no stone in the area, it is thought that the medieval builders used stone from the Midland quarries shipped down the River Ouse to Bedford and from there conveyed by horse and cart along the Roman roads to Wheathampstead.
Lime rendering works to south transept and south aisle, external masonry repairs to the west of the south aisle. Glazing works to south transept windows was also undertaken during this project.