There are two doors to the ground floor of Reginald's Tower; the original door, which is on the north side, away from the river, and the south door, which is a later 16th century insertion, facing the river. Both of these doors have been in use for visitors but because of noise, dust and wind, the guides requested that consideration be given to the fixing of an inner door to the quayside opening.
To preserve as much light as possible, a glass door was designed and ordered from a manufacturing firm. Carpenters from Dúchas, The Heritage Service of my Department, installed a timber subframe and a template was sent to this firm. The design was based on a complex survey, which incorporated a number of factors; the floor of the tower slopes unevenly outwards, the sides of the door opening are neither parallel nor vertical, the opening is within a circle and neither side of the opening is at 90 degrees to the inner wall, the arch over the opening is irregular in profile, the arch slopes irregularly to the outside, and there was only one point where the required width and height could be achieved within the opening.