The contract to design the Church was awarded to the firm of architects Gillespie, Kidd and Coia, 239 Saint Vincent Street, Glasgow. Doctor Jack Coia, shown in the leftmost picture drawn in the 1930s, was the main architect.

The picture on the far right is an artist impression of the planned building. It was drawn in November 1936.

The description below is adapted from the book Jack Coia, His Life and Work written by Robert W K C Rogerson in 1986.

The Church of Saint Peter in Chains, Ardrossan is built of reddish facing brick. The front elevation has a tower to the right, reminiscent of that at Stockholm Town Hall though much more simple. The main doorway, however, is striking in detail. The doorway has an ornate projecting keystone in stone at the centre of the expanding brick arch. The door feature continues to the gable roof and ends in a small well-detailed cross.

The tower is placed slightly behind the front facade and is perfectly plain apart from the belfry at the top. The tower has a doorway at the foot on the sea side with similar ornamental keystone carved with Saint Peter in Chains as the motif. The fenestration in the side elevations is most pleasing.

The interior of the Church is simpler than one would expect. It consists of a nave, four very large brick piers each 36 inches by 22 inches at either side with a large span between them. The aisle roofs are low, sloping down from the beams above the piers to the small side windows. The Stations of the Cross are located on the frieze, the encasure of the beams. The confessionals are positioned at both sides at the rear of the Church. There is a rear gallery approached by a stair in the tower. The whole of this rear area is finished in facing brick. The aisle walls and pillars are also in facing brick. The entrance porch is interesting and has small windows with Holy Water stoups in recesses beside them next to entrance doors to the Church.

The altar has on the top band the words Altare Privilegiatum in Roman Trajan lettering. Above this altar there is a most interesting canopy in plaster with more scallops at the edge, five of which have decorative panels in them. In the centre are the Keys of Saint Peter with the Bull of Saint Luke and the Eagle of Saint John to the right. To the left is the Lion of Saint Mark and the Angel of Saint Matthew. There is a side canopy on the left side of the Sanctuary with the words Tu Es Petrus Et Super Hanc Petram Aedificabo Ecclesiam Meum around it.