Concrete Masonry Units. One line of sustainable concrete masonry units (CMUs) is made with up to 30 percent recovered glass, offering the same advantages as conventional CMUs but with a less harmful environmental impact.
Another advantage of sustainable CMUs: their particles are smaller, reducing the size of the small voids typical in conventional CMUs, thereby reducing their permeability to water.
Masonry flashing. One type of through-the-wall/surface-mounted flashing made from 45 percent recycled material consists of a composite membrane with an adhesive backing. The flashing, designed to resist tearing, can be applied to masonry, concrete, steel, and wood. Stainless steel reglets and termination bars — flashing components embedded in masonry joints — can be obtained with an average of 60 percent recycled content.
Insulation. One brand of sustainable insulation is a thin nanocomposite coating sprayed, brushed, or rolled on like paint onto an interior wall surface. Although it is more expensive than conventional fiberglass insulation, it requires much less labor to install than adding batt insulation (the rolled matted sheets) to existing structures. The nanoparticles used in the coatings repel water, resist mold, and are anti-corrosive on metal surfaces.
Bricks. Durable, weather resistant, and non-flammable clay bricks are a popular choice in building construction. Although these do not deplete a scarce resource and can be crushed and reused as gravel, they don't contain much recycled content nor can they be recycled into new bricks. In some cases, intact bricks from historic buildings can be cleaned and reused but at an increased labor cost.
Sustainable bricks, which typically contain 30 to 100 percent of recycled material such as ceramic, glass, and iron oxides, are starting to gain traction as a viable green alternative in the construction industry. Recycled bricks have many of the same advantages as clay ones, but they add less to landfills. In addition, recycled bricks manufactured close to where the materials are collected and processed also reduce fuel and emissions from transportation, lessening the impact to the environment even more.
One area in which a building can reduce its carbon footprint is by choosing materials low in volatile organic compounds (VOCs), which are emitted as gases and can be harmful to the atmosphere. They are found in many building products and materials, such as paint and paint strippers (the strong fumes are VOCs), coatings, cleaners, fuels, wood preservatives, pesticides, and miscellaneous solvents.
Paints and coatings. Conventional oil-based paints contain high-levels of VOCs and can only be cleaned with toxic solvents, releasing even more VOCs into the air. As an alternative, latex paints - which use water as a solvent - provide good quality and durability and allow for easier and less-toxic cleanup. Also available: many low- or non-VOC stains and clear finishes for floors and cabinets.
Façade cleaners. Chemical cleaners, such as acid-based and alkali-based agents, are effective in removing dirt and stains from buildings. If they are applied improperly, however, they can discolor and/or damage masonry as well as leave hazardous materials in the run-off water after rinsing.
As an alternative, biodegradable gel-based, latex-based, and water-based products, which do not contain harsh solvents or emit VOCs, can be used on most surfaces, including brick, concrete, metal, stone, and wood.
Environmentally friendly cleaners may be painted or sprayed on and then stripped off, or in the case of paint-removal pastes, applied with a brush, roller, or spray and then scraped, squeegeed, or washed off. Not all cleaners work on all types of masonry, stains, and dirt, so it's important for your contractor and engineer/architect to follow manufacturer guidelines to avoid scarring the building's exterior.
Caulking. Traditional caulking agents are applied wet, and as they dry and cure in place, many release VOCs, formaldehyde, and other products that improve performance and longevity but may be harmful to breathe. Solvent-free caulking is available that emits a minimal number of VOCs. These non-flammable, non-toxic products are also resistant to shrinkage and discoloration.
LEED points. Buildings that use sustainable materials and follow environmentally sound practices receive points toward LEED (Leadership in Energy and Environmental Design) certification. But even if your cooperative is not pursuing, or eligible for, such certification, it can be cost-effective to incorporate a green approach to repair and upgrade work.
Contractors may be resistant to changing the way they've always done things, so they may not embrace your board's enthusiasm for making your repair and upgrade project green-friendly. Moreover, the particulars of each property make some sustainable practices harder to implement than others.
So, as the field continues to evolve, it will require education and due diligence on the part of owners, managers, and their engineers and architects to sort out what is right for each building. But by keeping green alternatives in mind and selecting them whenever possible, your cooperative — as well as the environment at large — will benefit.