Aurora Police Headquarters and Branch Court Facility Architect: Cordogan, Clark & Associates, Aurora, Ill. Structural engineer: Engineering Services Group Inc., Aurora, Ill. General contractor: Leopardo, Hoffman Estates, Ill. Mason contractor: Masonry Co. Inc., Wheeling, Ill. Material supplier: Masonry Accessories Inc., Joliet, Ill. Anchor supplier: Heckmann Building Products Inc., Melrose Park, Ill.

When completed in late 2009, the $70 million 200,000 square-foot Aurora Illinois Police Headquarters & Branch Court Facility will house 400 public safety employees and serve hundreds of visitors each day to serve Illinois’ second largest city. Aiming for LEED gold, thermal resistance of the building façade—along with sound structural connectivity—played a key role in achieving success.

The 25 acre site will consist of a three-story 160,000 square foot main building for the police headquarters and a branch court facility. There will also be a separate 40,000 square foot building for training and storage. The project is aiming for a gold rating from the U.S. Green Building Council for Leadership in Energy and Environmental Design (LEED).

Brick veneer to steel studs
The architect’s goal was to achieve a thermal resistance value of R-32. This was accomplished by using 6-inch cold-formed steel studs with batt insulation, 5/8-inch exterior gypsum board, a vapor barrier, 3 inches of rigid insulation, 3/8-inch ThermaDrain drainage system, an airspace, and brick veneer. Single screw barrel-type masonry anchors were installed through the ThermaDrain back to the steel studs. Adjustable hotdip galvanized pintle ties into the veneer completed the anchoring system. The single barrel-type anchor was selected because of its single point of penetration from the airspace back to the steel stud.

The anchor provides reduced thermal conductivity and has the ability to adjust inward to seal the ThermaDrain. The screw anchors were also fast and easy to install. The ThermaDrain allows cavity moisture to drain down the wall and out weep holes. Stainless steel drip-edge flashing is also installed at the bottom of the walls.



Precast panels
The precast panels were attached to the cold-formed steel studs using engineered stainless steel stone anchors. The engineering process includes an analysis of each unique shape of stone panel. This analysis provides the engineer with information to determine the anchor attachment locations and to ensure internal stone stresses are minimized to prevent cracking of the stone.

Typical loading conditions encountered by the precast cladding include self-weight, wind, and seismic loads, as well as thermal expansion and contraction forces. After the anchor locations are determined, the resulting reactions are utilized to select a specific type, size, arrangement, and material thickness of each anchor and appropriate anchor fasteners. The engineered anchors for the Aurora Police project were 1/8-inch-thick x 1-1/4-inch-wide with a 3/4-inch split-bend into the precast panels. The anchors were attached to the steel studs thru the gypsum board and vapor barrier with #10 self-drilling steel stud screws. The insulation and ThermaDrain were placed above and below the anchor to avoid crushing the insulation from compression loads. Similar stone anchors with a straight bend were used to tie the top and bottom precast panels.