Aluminum and the Sustainable Home: What You Should Know

Where Is Aluminum Used in our Homes? 

Besides aluminum foil and pots and pans, many homeowners might have aluminum in their home's structural elements without ever knowing it. Aluminum is commonly used in metal roofing as a coating that helps preserve the underlying steel and increase roofing durability. Similarly, aluminum siding is also widely used for a low-cost external cladding option.

Older homes might also have some or all of their electrical wiring from aluminum. While aluminum doesn't boast a great deal of conductivity, like copper, it is lightweight, so many power lines are made from aluminum wires. Some homes contain windows and door frames made from aluminum, along with interior curtain walls. Also, some LED bulbs contain large amounts of aluminum in their manufacture.

What Are The Advantages of Aluminum For Home Building?

The most oft-cited benefit of using aluminum for home construction is incredibly lightweight. Compared to other materials, aluminum has an exceptional strength-to-weight ratio and weighs up to 65 percent less than steel. For houses that use aluminum posts and beams, the structural element will be lighter without sacrificing strength and durability, especially compared to steel posts and beams. Aluminum allows homeowners to reduce their foundation's size and depth, thus potentially helping to reduce the volume of cement required for the home's foundation.  

Aluminum is also resistant to corrosion. For this reason, it is sometimes used as a reflective and protective coating on steel roofing. One study found that coated aluminum roofs can reflect up to 95 percent of sunlight. This coating drastically improves the thermal performance of homes with a metal roof. It helps to reduce cooling loads during the summer months.

What Are The Downsides of Using Aluminum For Homebuilding?

There are two main drawbacks to using aluminum in your home. First, mining aluminum is a highly energy-intensive process that causes significant damage to the earth's ecosystems. We will take a closer look at aluminum mining below.

Secondly, relying on aluminum for certain aspects of your home can compromise acoustic performance, especially if you opt for aluminum siding. While aluminum siding is generally one of the most inexpensive exterior cladding options, it can be loud, especially during high winds or rainstorms. Also, aluminum is certainly not a "natural-looking" product. For homeowners wanting a more natural feel to their home, aluminum products will inevitably look like metal. Metal is often considered cold or industrial-looking, but it can be appealing to a modern aesthetic.

How Does Mining Aluminum Affect the Environment?

From a mining perspective, obtaining raw aluminum often requires massive strip mines. Strip mines have far-reaching environmental effects, including destroying forests, landscapes, and wildlife habitats. These mines also lead to soil erosion and the pollution of waterways. Once mined, the aluminum compounds need to be separated through electrolysis, which takes enormous electricity.

What Is the Embodied Energy of Aluminum?

Newly produced aluminum has a high embodied energy footprint, measured by the "process energy requirement," or PER. PER is a measure of the amount of energy required to manufacture specific building materials. Since aluminum requires strip mining and energy-intensive processes to separate the aluminum through electrolysis, its PER is higher than virtually all other commonly used building materials.

According to studies done by the Australian government, aluminum products used in housing construction have a PER embodied energy rating of 170. This rating is the highest of all commonly used building materials. For comparison's sake, plywood has a 10.4 PER, while cement has a PER of 5.6. Even copper and synthetic rubber products have a significantly lower PER than aluminum, respectively, at 100 and 110 PER.

Does Recycled Aluminum Have a High Embodied Energy?

Aluminum from a recycled source contains less than 10 percent of aluminum's embodied energy manufactured from raw materials. When this is taken into account, aluminum's embodied energy footprint is much lower than concrete, plastics, and even masonry.