By adding curves to shape the 102,000-square-foot semi-circular library, further set off by two cubic stones -- Missouri Red granite and Rosati sandstone -- the architects achieved a distinguishing look for the exterior of the library. "Missouri Red granite had a tradition of use in the state, which is why we selected it," said Bottino. "The light cream-colored sandstone, which has darker veining, complemented the granite well."

Holzman concurred with Bottino, adding the importance of selecting stones from the area. "We like to use materials from the locale and region where we are working," said Holzman. "The reason we like to do that is because the people in the community are familiar with them, so it allows a connection with the tradition and culture of the area. Older structures in the area were designed with those stones, so it connects the building in the community."

Once the circular form of the library came to fruition, the architects then had to decide how to further separate the northern side which faces a civic, public area from the southern side of the building, which faces a residential area. They also wanted to differentiate between functions of the building. "The building is organized so the northern portion is the collection and public area, while the southern portion is the staff area," said Bottino. "The overall goal for us was to fit a prominent civic building on the site, while tying together residential and public areas. We decided to use the red granite on the perimeter and northern side of the half-circular shape of the library, and the low retaining wall for the parking section, to face the civic side.

"The sandstone was used on the southern side --for the straight edge of the half-circle -- to face the residential side."

The granite used was quarried at Missouri Red Quarries, Inc. in Ironton, MO, and fabricated by Granicor, Inc., in St. Augustin, Canada. While about 17,600 square feet of granite was used for cladding, 3,000 square feet of the material was used for the low retaining wall.

A total of 13,000 square feet of Rosati sandstone -- supplied by Rosati Sandstone of St. James, MO, and fabricated by Earthworks, Inc. of Perryville, MO -- was used for the building.

"A challenge we had was locating the material and determining whether it was available," said Holzman. "These materials are typically used on a small scale and it is infrequent that they are used on a larger scale. We found a good source for the materials, and it was supplied in a large enough quantity in an adequate time, so it worked out."

Once the stones were selected, the architects then chose a variety of cuts and finishes for the materials. "The granite was split-faced with a sawn top and bottom and split ends," said Bottino. "It was nominally 12 inches high and varied in length from 18 to 36 inches. Periodically in the walls, there are also horizontal bands in ashlar, which were 2, 4 and 6 inches in height and random lengths, which tied the windows together. When you look at it at an angle, there is a difference in texture.

"Interspersed throughout the granite walls are also large, quarry-faced blocks with a rock-face, dubbed "roughbacks," for a rougher, larger scale texture -- they were 3 feet tall and 5 to 7 feet long.

"The majority of sandstone was 10 inches in height by random lengths, split-faced with split ends and a sawn top and bottom," Bottino continued. "Smooth, sawn sandstone was also used as 24 inches in height by 12-inch-wide pieces, set slightly turned to form a saw-tooth pattern."

Construction of the addition and renovation began in September 2000 and ended in September 2002. The general contractor, KCI Construction Co. of St. Louis, MO, commissioned Wulff Brothers Masonry Corp. of Columbia to install the stone. "A challenge was to get the masons to understand the effect we were after," said Bottino. "Through the use of mockups -- to represent different patterns of the building -- we were allowed to set the standard of workmanship and detailing acceptable. One mockup had to be rebuilt, but once the masons understood, it went up without difficulty."

The stone installation took about a year, with 50 to 60 workers a day, according to Dennis Murray of KCI Construction Co. "The installation for the majority of the exterior was done using stainless steel clips, and stainless steel adjustable fasteners," he said. "The outside perimeter of granite was stacked on a mortar bed. It was a typical installation for us. There were no difficulties with the installation of the stone."

Once the project was completed, the reaction from the public has been positive. "Any change to an existing institution provokes a bit of anxiety," said Holzman. "At the dedication ceremony, the mayor made an interesting presentation, saying that he believes architecture can be a positive force on the environment. He also read a letter from a boy scout in the community, who asked what everyone had been arguing about in regards to the library design -- he thought it came out so well. The result of the project was that the library readership has gone up and everyone is enjoying the building."

End box

Columbia Public Library
Columbia, MO
Architect: Hardy Holzman Pfeiffer Associates, New York, NY
Stone Supplier: Missouri Red Quarries, Inc. in Ironton, MO (granite); Rosati Sandstone, St. James, MO (sandstone)
Stone Fabricators: Granicor, Inc., St. Augustin, Canada (granite); Earthworks, Inc., Perryville, MO
General Contractor: KCI Construction Co., St. Louis, MO
Stone Installer: Wulff Brothers Masonry Corp., Columbia, MO