Gilston Peel is a simple rectangular tower, measuring around 9.5m by 6.7m, with walls 1.0m thick at the base.

It was ruinous by the early 19th century, but was restored as a two storey dwelling, changing many of the original features, one of which survives as a small window blocked-up in the south-east gable.

A small one storey extension has been built on the west wall, and the tower seems to have undergone further (and rather unsympathetic) restoration in the late 20th or early 21st century, with nine modern windows installed in the south wall, and four in the north wall.