The traditional architecture of Holy Spirit follows the design of the Romanesque Revival period, which began around the beginning of the 20th century. The style is similar to Richardsonian Architecture, after H. H. Richardson, who used brick and stone to create heavy, solid designs, reflective of Romanesque architecture of the 11th and 12th centuries. The brick detailing of Holy Spirit is based on that period, and the color is similar to churches in Tuscan, Italy. Among the notable masonry features is the stair-stepped pattern over the entrance, which juts over three feet from the main surface of the wall. It won the 1994 Award of Excellence, first place, from the Masonry Association of Georgia. The exterior walls were built with 350,000 bricks; 88 tons of green Vermont slate was used for the roof. Within the roofline there is a series of copper lightning conductors, the last of which is encased in a five-foot-tall finial in the shape of a fleur-de-lis. The cross at the apex of the tower is of lightweight aluminum. Parishioners signed the base member and capping steel beam before the cross was set in place.