High Concrete Group LLC has introduced ThinCastTM, the thinnest precast concrete rainscreen panel available on the market. Designed for use in commercial, institutional, retail, and low- to high-rise construction, this innovation provides architects with the natural beauty and character of concrete in lightweight panels that accomplish their rainscreen design goals.
Location: Wheaton, Ill.
Type of Precast: Architectural Cladding
Size: 150,000 sq. ft. (41,800 sq. ft. of architectural precast cladding)
Developer Chooses Precast for Traditional Theme within Schedule and Budget
Local businessmen in a Wheaton, a quaint suburban community outside Chicago, saw an opportunity to collaborate with community leadership to redevelop an underutilized assemblage of commercially zoned parcels. They visualized a building with a ground floor retail function typical of a traditional business district development. The image of the architectural precast office building needed to convey durability, permanence and civic-mindedness. The anchor tenant and development team guided the decision to emulate the classical look of the earlier buildings found in the city’s financial exchange district. The decision to use architectural precast to achieve this ambitious expression was recommended by the project team.
The Wheaton community is noted for its conservative and traditional values that are exemplified by the many examples of its fine traditionally-styled architecture. Although abounded by many examples of colonial style buildings, the adjacent turn-of-the-century Romanesque courthouse and other limestone-clad buildings provided a strong contextual setting that was reinforced development team’s vision. This new development serves as a significant anchor the anticipated expansion of downtown redevelopment south of a commuter rail.
The site totals 1.64 acres and includes a four-story parking garage that totals 140,646 square feet and provides parking for approximately 428 vehicles. The first floor of the building is intended as retail space.
The building’s base is two stories in height and employs a tall arcade on two sides at the ground level to provide covered, pedestrian-friendly circulation alongside shop windows and past the main lobby entrance. A projecting cornice defines the top of the building’s base. The remaining upper two stories employ a series of tall piers that support arched openings. Color contrasting window framing and spandrels infill the arched openings. A frieze and projecting cornice crown the top of the building.
A key factor in the choice of precast architectural panels was developer’s preference. The firm regularly relies on precast to meet the constraints of its construction schedules and to perform reliably long term. However, “as developers we would not do this design on a spec basis,” notes Rob Ezerins of architect Opus Architects & Engineers, Inc. “This is very peculiar to the owner’s and tenant’s shared vision.”
The design team used stone formliner to create cornices and rustications that formed 20-inch x 36-inch “blocks” in the large panels, to break up the mass andrecreate the finish and texture of Joliet limestone used on a nearby landmark building. The buff colored panels are acid etched with the use of rusticated stone form-liner to suggest what the material of the building might be, without betraying that it’s precast, to be true to the 100-year old buildings nearby. Striking 5-foot x 3-foot keystones top the large arched windows.
Despite the intricate detailing, the team’s economic and repetitive use of building components made the execution of the design feasible. “The formwork at the precaster’s factory was built with the same care as wood furniture,” says Ezerins. “They were very mindful in helping us realize the client’s vision.”
The project represents a sensible form of sustainable design, and could be considered for LEED Neighborhood Development though it’s not in the plan, says the architect. Daylighting with large window openings was a major part of the project conception, which had to be balanced with the look of a load-bearing structure typical of classical buildings. The windows were made as large as possible to allow light in and to make the building more marketable, as more glass area often reads to tenants as more flexibility in laying out office space.
In fact, the building has as much glass area as many more contemporary office buildings. The large window openings were originally intended to be curtainwall; however, there is not a stitch of curtainwall, which would be antithetical to the traditional look. Further, cost engineering and the developer’s interest in long-term performance favored using simple glazing. Decorative metal accent panels were applied to the precast panels after the last stage of the exterior shell to reduce the chance of damage.
The building’s nighttime image was carefully planned to emphasize the building’s features from the street. Sconces placed between rusticated portions bring out the formliner textures on the lower floors. LED uplighting at each of the piers on the third story sill reinforces the stone image from a distance.