It is a long, low barn, with a thatched roof, and walls built of brick, flint and limestone. It has large doors with timber lintels. The barn was commissioned by Sir William Paston III as a grain store and threshing barn. It is approximately 70 metres long, 9 metres wide and 16 metres high. It has been granted Grade II* Listed Building status by English Heritage due to its architectural and historical importance. There are three 30-metre long Victorian wings on the eastern side of the barn, added to house cattle. Unusually for a barn it has two date stones, one over an entrance and one in a gable end. Additionally, a plaque over the south door records: "THE BILDING OF THIS BEARNE IS Bl SIR W PASTON KNIGHTE".