Perforated Anodized Aluminum Ideally Suited for Austin Central Library Aluminum panels from Lorin ensure durability of the decorative and functional metal building exterior

By Phil Pearce, Vice President Sales and Marketing, Lorin Industries, Inc.

Recently, the City of Austin, Texas built an entirely new central library building to serve its citizens, and in designing the building, architects from Lake Flato Architects and Shepley Bulfinch chose perforated anodized aluminum from Lorin Industries, Inc. as a central façade design element. The new Austin Central Library building, opened to the public in October 2017, makes full use of the functional and aesthetic benefits of the perforated anodized aluminum panels: many panels provide shade for the building and its entrances, while one large panel incorporates literary quotations that are visible on the buildings floor as light shines through the metal, and all of the panels add to the overall building aesthetic.

Austin Central Library project background
The new Austin Central Library is a 200,000 sq. ft. building, serving the entire community of Austin, Texas. The library was designed by architects from Lake Flato Architects and Shepley Bulfinch to be a gathering place for all of the citizens of Austin, with a large, six-story atrium intended to function as "the new living room for Austin," explained Jonathan Smith of Lake Flato Architects. Around the edges of the atrium, there are a variety of spaces designed for different kinds of activities, including public computers, shared learning rooms, co-working spaces, and more. The rest of the building features a number of other dedicated spaces: a traditional quiet reading room, half of an entire floor of the six-story building dedicated to children and teens, and plenty of space for books and other lendable materials. On top of it all is a rooftop outdoor reading garden, with a live shade oak tree growing atop the 6th floor roof.

The library building is situated on a site that functions as a gateway to downtown Austin, Smith explained, and so the exterior of the building was designed to suit the site itself and to be in conversation with surrounding buildings, including the City Hall building just four blocks away. Much of the building façade is constructed with local limestone, and on the South side, cantilevering off the building, is a metal façade component that serves as a set of large, screened-in porches overlooking the nearby lake.

Perforated anodized aluminum as a central design element
Early, architects on the project knew they wanted a unique exterior for the building, and knew that they wanted to use aluminum for its low weight and high recycled content, since the building is on track for LEED Platinum certification. In particular, the architects wanted corrugated, perforated aluminum with a deeper, more three-dimensional look than paint could offer to be part of the screened porch section of the building exterior.

The search for such a material led them to Lorin Industries Inc., the global industry leader in continuous coil anodizing of aluminum. Lorins unique aluminum anodizing process not only provides the kind of textured, three-dimensional appearance that the architects were searching for, but also protects the metal from corrosion, ensuring durability and a long lifespan.
The architects corresponded with Lorin experts to produce and compare samples of different colored aluminum panels alongside the local limestone that would form the other portion of the building exterior.

With these samples and a larger mockup, the teams worked together to finalize the color and finally to produce the panels, framing, and closures for the corrugated perforated aluminum exterior. The panels feature different levels of perforation based on where in the project they are, with different patterns or percentages of the metal open to provide more shade or greater visibility. Panels of the Lorin anodized aluminum fold off the façade and become the entry canopies over the three main entries of the building, providing shade and a unified exterior appearance.

Benefits of perforated anodized aluminum
The perforated anodized aluminum provided the Austin Central Library project with the exact mixture of unique aesthetics and functionality that the architects sought in designing the building. The light weight attribute of the panels was important in the structural design of the building, as its simpler connections helped to save costs for the public building. Additionally, the unmatched durability of Lorin anodized aluminum will preserve both the aesthetic and practical functions of the metal panels throughout the life of the building.

Typically, perforated anodized aluminum is created by punching or stamping a specific hole pattern onto the metal, either in a continuous coil form, or by sheet. The coil or sheet is fed through a computer-controlled punch press, which is designed to efficiently and quickly perforate a variety of patterns onto the metal. After the metal is perforated, it is anodized to provide the unique electrochemical protection, even inside the holes, available only with aluminum processed in this way.

Once the design is complete and the perforated panels have been produced, the installation process starts with installing the framing. Once the framing is complete, the installer can then install the panels according to the details and guidelines on the perforators supplied architectural shop drawings. Perforated panels are usually one of the last elements to be installed on a building. With perforated anodized aluminum in particular, most panels are light enough to install without a crane, which is one of the reasons why aluminum is so highly favored for perforated metals building projects like the Austin library, especially when saving on installation costs is important.

With its durability, light weight, protection from wind and sun, contributions to "green" building efforts, and finely-tuned finish, Lorin perforated anodized aluminum was uniquely and ideally suited to the Austin Central Library project.