Additions to weathered, worn facades include extruded-aluminum sunshades and blades to bring buildings into the 21st century.
Old age, or at least middle age, is setting in for the popular all-glass and concrete commercial buildings constructed in the last half-century that dot the landscapes of American cities. The materials weather and appear worn out over time or take on a dull sameness.
This is sparking aesthetic issues–not to mention a growing focus on green materials and energy-efficient, thermal-performance concerns about glass, especially in the northeast– that are prompting building owners and architects to seek alternatives to smarten the buildings’ appearances with material conversions. Increasingly, designers are looking to extruded-aluminum products to bring building facades into the 21st century, while also providing durability into the future.
Aluminum extrusions offer several ways to spruce up a building to give it an architectural design aesthetic and enhanced sustainability. Architects are continuing to use extrusions to break up the sameness of exterior glass or concrete walls. As showcased in the 500 Folsom building, currently in production in San Francisco, aluminum extrusions can provide an interesting aesthetic and add to a building’s visual appeal.
The Anaha Tower, Honolulu, is another unique building because of the architectural features of the curved glass and curved curtainwall. A difficult project for glaziers to complete, the result is a beautiful design and adds to a city’s visual appeal.
Aluminum-extrusion blades that act as sunshades are also used on large-scale glass curtainwall facades. The blades are integrated in the curtainwall with assembly blocks to be adjusted on site. Blades can be installed horizontally or vertically and finished in a variety of ways that a designer, architect, or owner favors to make a building more unique. Blade length and width vary depending on the location of the building, the total hours of sunlight each year, and the building’s exposure. Typically, larger or wider sunshades are used in areas that experience more sunlight and on the western and southern exposures of a building. Sunshades are used extensively at the airport in Sacramento, CA. The facility used extruded aluminum sunshades to achieve LEED Silver certification for Central Terminal B, along with maximizing daylight and reducing internal energy use.
Extruded-aluminum sunshades not only upgrade the appearance of a building, they are an integral part of achieving required LEED accreditation. In addition, their use adds a different architectural element that provides long-term durability and refinement.
In a glass-dominated building, double-skin facades capture heat between the glass walls to decrease heat loss in the winter and ventilate in the summer to lessen heat gain. Combined with the extruded-aluminum sunshading system between the glass walls, energy performance in summer is further enhanced. Additionally, sunshades deliver a complexity to the building’s appearance, providing a different flair than the flat, monotonous look of the original box-like design.
For window retrofitting, extruded-aluminum-clad vinyl has grown in popularity, including a hybrid casement window fabricated as a vinyl-only window, an aluminum-clad vinyl unit, and a vinyl window with aluminum on the outside and wood on the inside.
The use of aluminum extrusions in retrofitting older buildings is a trend that will continue. Architects see its value in keeping the original, while updating the building at the same time.
Sapa Extrusions Inc., Rosemont, IL, sapagroup.com, provided information for this article.