Material efficiency

Building construction can be a materially consumptive endeavor.

Material efficiency of construction projects or physical processes is a description or metric which expresses the degree in which raw materials are consumed, incorporated, or wasted, as compared to previous measures.^[1] Making a usable item out of thinner stock than a prior version increases the material efficiency of the manufacturing process. Material efficiency goes hand in hand with Green building and Energy conservation, as well as any other ways of incorporating Renewable resource's in the building process from start to finish.

Material efficiency can also mean the degree in which a material can handle a particular load, strain or weight upon it. Material efficiency can be achieved through using recycled materials, materials that use renewable energy, and other ways. For example, using recycled steel instead of new steel "reduces the energy produced in making the steel by 75 percent, and saves space in landfills as well."^[2] Material efficiency, "entails the pursuit of the technical strategies, business models, consumer preferences and policy instruments that would lead to a substantial reduction in the production of high-volume energy-intensive materials required to deliver human well-being. The motivations for material efficiency include reducing energy demand, reducing the emissions and other environmental impacts of industry, and increasing national resource security. With a growing population and increasing wealth, demand for material extraction and processing is likely to double in the next 40 years. The environmental impacts of the required processing will become critical."^[3]

Material efficiency in the building process

Using materials that are more "efficient" in the building process today can be less expensive and energy intensive than using new building materials. An example of this would be using recycled steel to erect the frame of a building instead of using wooden timbers. Using recycled steel saves room in landfills that the steel would otherwise be taking up, saves 75% of the energy required to produce steel in the production process, and saves trees from being cut down to build homes. The recycled steel can be fashioned in the exact dimensions needed for building and can be made into "customized steel beams and panels to fit each specific design."^[2] These new, more efficient materials, can cost more initially when being used in building but in time will save money through lower heating/cooling bills, lower electric bills, and other kinds of bills. Over time you can recoup your money and save even more all the while staying comfortable inside your home.

Lighting

There are three types of light bulbs today that are very popular: Incandescent Light Bulbs, Compact Fluorescent Light Bulbs (CFL's), and Light Emitting Diodes (LED's). Electric lighting alone can account for around 14% of your current home energy bill.^[4] In addition to this, only 10 percent of the electricity used by an incandescent bulb generates light; the rest is wasted.^[4] Here are two tables comparing the three types of lightbulbs:

^[5]

Visual Representation Of Electricity Use By Bulb Type With Halogen Bulbs Included.

^[5]

Another way to reduce electricity conumption and save money with lighting is by installing dimming switches with these bulbs. A dimmer can increase and decrease the amount of light emitted by the bulb to your liking. It can not make a light bulb brighter than its maximum already is but it can reduce it thus using less electricity and saving you money.^[4]

Insulation Techniques

Popular materials used for insulation are fiber glass, rock wool, and slag wool. After being manufactured these items require no energy to use and require no maintenance unless damaged. Using inflation properly is the most effective way to reduce energy use and green house gas emissions.^[6]

Facts about today's insulation:

• Using insulation reduces average home heating and cooling costs by around 20%.^[6]
• For every Btu consumed in the production of insulation, 12 Btus are saved each year by the use of insulation.^[6]
• For every pound of carbon dioxide emitted in the production of insulation, 330 pounds of carbon dioxide are avoided by the use of insulation.^[6]
• Fiber glass and rock and slag wool products are reusable. They can be easily removed and put back into place.^[6]
• According to the Department of Energy, heating and cooling systems use more than half of the energy consumed in American homes. Typically, 42% of the average family’s utility bill goes to keeping homes at a comfortable temperature. The energy sources that power these heating and cooling systems emit more than 500 million tons of carbon dioxide and 12% of the nitrogen oxide emissions, the active components in acid rain. By combining proper equipment maintenance, upgrades, insulation, weatherization, and thermostat management, you can reduce your energy bills and emissions by half.^[6]

Plant-based Polyurethane Rigid Foam

There is a new "generation" of insulation being released to the public recently. Plant-based Polyurethane Rigid Foam is made from plants such as bamboo, hemp, and kelp, that "offers high moisture and heat resistance, excellent acoustics and protection against mold and pests. It also has a higher R-value than fiberglass or polystyrene, meaning that it has a higher thermal resistance and insulates better."^[2] The hygroscopic properties of bio-based insulation mean that they can absorb and store moisture from the surrounding air, according to project partner Patricia María Pérez Tarancón at Acciona, Madrid, Spain. "The material behaves as a moisture buffer," she says, "This softens the relative humidity changes in the environment, reducing risks from common pollutants such as bacteria, viruses, chemical reactions, allergies and respiratory infections, as well as reducing the need for air-conditioning."^[7] These plant-based insulation techniques can be cheaper, healthier, save more energy in houses and buildings, as well as cut energy consumption in the manufacturing process of insulation.

Cool Roofing

Another more efficient way to cut energy consumption and save money along with newer plant-based insulation is with proper roofing. "Cool Roofing" involves using roofing which direct sunlight back into the atmosphere instead of being absorbed by the material and being passed into the building.^[2] This Cool Roofing can save money by lowering the cost of keeping a building cool with air conditioners. The same process can be used to keep heat in and lower the cost of a heating bill. A cool roof is one that has been designed to reflect more sunlight and absorb less heat than a standard roof.^[8] Cool roofs can be made of a highly reflective type of paint, a sheet covering, or highly reflective tiles or shingles.^[8] Benefits of a Cool Roof:

• Reducing energy bills by decreasing air conditioning needs.^[8]
• Improving indoor comfort for spaces that are not air conditioned.^[8]
• Decreasing roof temperature, which may extend roof service life.^[8]
• Reduce local air temperatures (sometimes referred to as the urban heat island effect).^[8]
• Lower peak electricity demand, which can help prevent power outages.^[8]
• Reduce power plant emissions, including carbon dioxide, sulfur dioxide, nitrous oxides, and mercury, by reducing cooling energy use in buildings.^[8]

Recycled Materials vs New Materials

Incorporating recycled materials into the manufacturing process of new goods is an integral change. Mineral resources are finite, such as bauxite ore for aluminum or fossil fuels to make plastics, so it is imperative to start reusing what we have already mined so that we do not deplete what is left. There are many technologies available that help tremendously with recycling efforts such as near-infrared equipment which, "is a common sortation technology in large recycling operations and can accurately identify many different types of polymers."^[9] Near-infrared equipment is a much easier way to sort through plastics compared to the human eye.

Aluminum

Aluminum offers the most savings, with cans from recycled material requiring as little as 4% of the energy required to make the same cans from bauxite ore. Metals don't degrade as they're recycled in the same way plastics and paper do, fibers shortening every cycle, so many metals are prime candidates for recycling, especially considering their high value per ton compared to other recyclables.^[10]

Plastics

Polystyrene from recycled material costs 88% less than without recycling, but a negligible amount of polystyrene is recycled in the United States because of the difficulty sorting it from other plastics. Other plastic products like polyethylene terephthalate soft drink bottles cost 76% less to manufacture form recycled materials, and this percentage as well as the variety of plastics that can be recycled is expected to increase with new separation technologies such as froth floatation and skin flotation. [3,6] Nonetheless, plastic degrades every time it's recycled, so some plastic will always need to come directly from fossil oils if such products are to continue to be produced.^[10]

Paper

Paper (in particular newspaper) and glass have lower energy savings than the previous materials, with recycled products costing 45% and 21% less energy respectively. Recycled paper has a large market in China, although work still needs to be done to facilitate mixed paper recycling as opposed to newspaper.^[10]

If we were to utilize these recycling methods we would not have to expend energy and resources on mining for new resources to use in manufacturing. Recycled aluminum, for example, has the same properties as newly manufactured aluminum but expends so much less energy in the manufacturing process. This is assuming however that recycling plants are being run in the most efficient ways possible.^[10]

Reusing Materials

Reusing current materials uses even less energy than recycling. Reusing is preferred to recycling because it eliminates the cost of transport to a recycling plant, sorting, re-manufacturing, distributing, and there are no wages needed to be paid to employees for doing these tasks. Reusable containers only have to be manufactured once for hundreds or thousands of uses (such as a water bottle used every day for years), and the energy cost between uses is approximately that of cleaning the container with soap and water, a negligible expense compared to sorting, melting down, and pouring the material into a mold again, for example.^[10] Reusing containers could, in theory, replace recyclable containers and one-use containers, if made out of a durable enough material.^[10] There are inconveniences that go along with reusing materials however. Some of these inconveniences include having to clean the containers between uses, carrying around full or empty containers, and they require a time commitment due to having to hold on to them instead of throwing them away.^[10]

Glass and Paper

For products with glass containers, a deposit-refund system to encourage people to return the containers to the store for reuse seems more useful than recycling, given glass's durability and the small energy savings for recycling it.^[10] Reuse doesn't work as well for printed paper, or for non-container metal or plastic items such as electronics or packing material, so recycling may still be the best option in these cases.^[10]

See also

• Conservation ethic
• Conservation movement
• Ecological deficit
• Environmental protection
• Global hectare
• Green building
• Energy conservation
• Recycling
• Renewable energy

References