To achieve a Zero Energy Design designation, the three-bedroom house was equipped with mainly electric appliances and onsite power generation provided by a 6.5-kWh solar array. Further enhancing the sustainable design, a rainwater collection system off the rear of the home–designed to emulate a waterfall–funneled stormwater into two 2,000-gallon tanks under the home.

The Carmel Valley climate includes fluctuating temperatures and risk of fire, so the home was designed to resist these elements while also providing sustainability in both energy efficiency and material selection. The aluminum windows provided an option for recyclability and durability while contributing to the energy efficiency of the home. “The home was designed to be sustainable and resilient,” Goodwin said.

“The choice to have aluminum frames for doors and windows provides so much more than just an aesthetically superior option for contemporary residences and commercial projects,” he added. “But much like an automobile, you feel the difference when up close to an aluminum or metal frame compared to vinyl, fiberglass, or the like. The feeling of an aluminum frame adds sophistication and weight to any detail. It feels more prominent and thus your project will reap the benefits of material that is strong and timeless.”

ALUMINUM: THE ORIGIN STORY

To understand the benefits of aluminum as a building material, it is important to learn how this metal was first discovered and processed. In 1887, Austrian engineer Carl Josef Bayer developed a chemical process to extract alumina from bauxite, the third most plentiful ore on earth. The basic process is still used today. In 1888, the Pittsburgh Reduction Company launched the first smelting plant in North America. Aluminum is now produced with far less energy and at a much lower cost. In the early 1920s, for example, the cost of aluminum was reduced by 80% because of innovations in the production process.

Unlike other metals with limited supply, known bauxite deposits are sufficient to support the current production rate of aluminum for another 300 years. Open-cast methods are usually used, and great care is taken to restore and revegetate mine sites. Globally, the area rehabilitated each year equals the area being mined.

Aluminum alloys mix aluminum metal with other elements such as copper, magnesium, manganese, silicon, tin, and zinc. They can be processed into different forms depending on the method of processing. The extrusion process, which forms longer, thinner pieces, is often used in the building industry, mostly for manufacturing doors and windows.

Because aluminum instantly forms a tenacious oxide film that provides protection against corrosion after extrusion, it has an advantage over steel where the iron oxide (rust) in steel can spall off to expose the metal to corrosion. For aluminum solutions, additional finishing is generally not needed except for aesthetic or severe service conditions (e.g., salt spray, heavy pollution). When additional finishing is desired, anodizing or paint (either liquid or powder) is typically specified. Anodizing is an electrochemical process that thickens and toughens the naturally occurring protective oxide.

Liquid and powder coatings are multistep processes that coat and protect the aluminum substrate and enhance its appearance. The processes range from a single-coat liquid or powder to a four-coat polyvinylidene fluoride (PVDF) liquid using a primer, barrier coat, color coat, and clear coat. Powder coating provides excellent hardness and mar resistance, while liquid coatings can utilize a protective primer and metallic topcoats to achieve many unique appearances. Fluoropolymer systems have been the first choice for curtain walls for many years, and they are still considered the premier system for this application.

Mechanical finishing, such as brushing or sandblasting, is also employed occasionally. Most extruders have either in-house paint and/or anodizing capabilities or finishing service relationships that facilitate a finished and fabricated component. American Architectural Manufacturers Association (AAMA) specifications 2603, 2604, or 2605 are generally used to define paint finish performance and parameters, while AAMA 611 Class l or Class ll specifications are used to define anodizing.

Photo by Philippe Newman; courtesy of All Weather Architectural Aluminum

Selection of coatings for aluminum fenestration particularly Class I anodization is critical to ensure both aesthetic appeal, design consistency, and durability. The Shipyard Condos at Hunters Point.