[3] Generally, a medieval undercroft was built with at least three vaulted bays depending on the wealth or storage needs of the owner.

Being constructed of masonry they were costly to build and only could have been afforded by rich merchants which reveals that Guildford was a wealthy town during the Middle Ages.

[1][3] The Undercroft at Guildford is late 13th-century in date and is believed to have belonged to the house of a merchant above it who dealt in wine or expensive cloths or silk.

That near the steps shows the head of a woman wearing a wimple which was fashionable women's headwear in the late 13th century.

By the far corner in the uphill wall a narrow doorway can be found which led to a spiral staircase to the house above which supports the theory that the Undercroft was originally built as a shop.