Granaries were an important feature of all Roman forts. They not only housed the grain for the troops, but also stored valuable equipment. Each fort was supposed to hold a year's supply of food in case they fell under siege. The granary buildings were usually situated in the centre of Roman forts as far as possible from the reach of attackers fire arrows.
Granaries were raised off the ground in order to keep grain damp free and to allow air to circulate easily.
The granary at the Lunt was sited to the west of the Principia, and dates to between AD64 and AD78. It was built on top of a structure which has been identified as the commanding officers house.
The granary was the next feature to be reconstructed, in 1973. The reconstructions were carried out by the Royal Engineers using substantial donations from The Observer newspaper and Lord Iliffe, the owner of the Coventry Evening Telegraph.
The granary was reconstructed in elm, mainly as a result of the felling of a number of elm trees due to Dutch Elm Disease, though there was evidence of elm timber found on the site.
It took 18 men from 31 Base Workshop Squadron 10 days to build the structure using prefabricated timber.
The posts were set into their original positions in twelve foundation trenches. The raised floor was then added with loading bays at either end. The roof was made from elm shingles and was relatively steep in pitch to allow for high rainfall. The building measured 21.34m x 9.14m and was 9.14m in height at the roof apex.
The interior of the granary was arranged as a museum with three sections. The first had elm storage bins which would have been a feature of the original granary; the central section housed displays about the Roman Army using finds from the site and elsewhere. There was a particular emphasis on the cavalry. The final section was a small shop with a sales counter.
The museum was opened by the Right Honourable Lord Iliffe of Yattendon (Bart.) on 18th June 1974.
There were two more granaries in the fort. Unusually, these two buildings were not in the centre of the camp but were built close to the north edge. These two extra storehouses support the belief that cavalry were stationed at the fort.