I had the pleasure of exploring the tropical rainforest on the island of Puerto Rico during my vacation. I was surprised to learn that this was the only rainforest under the supervision of the U.S. Forest Service in any U.S. territory. Hawaii is home to other rainforests, but they are part of the National Park Service—a little trivia to use at the next cocktail party.
Rainforests are the home to more than 50 percent of all species on Earth. They are also responsible for almost 30 percent of the world’s oxygen turnover through photosynthesis from carbon dioxide. I was struck by the size of the plants and trees, as well as the fragile nature of the surroundings. The strange sounds of tree frogs, birds, flowing water and wind moving through the vegetation was a unique experience.
Although this was vacation, I quickly related the rainforest to the building construction industry. We often forget there is no waste in nature. A tree or plant at the end of its life will die, decay and return nutrients to the soil of the rainforest. The soil of the rainforest is not very deep or rich in minerals, so it relies on decaying vegetation to benefit new growth. The sun is the primary source of energy for the Earth, and the rainforest takes advantage of this fact. Tall mahogany or teak trees, some more than 150-feet high, create a thick layer of large leaves that absorb 98 percent of the sunlight that strikes the rainforest. With only 2 percent of the sunlight reaching the forest floor, there is very little vegetation below, which allows for walking and exploring with little difficulty.
Water is captured by the plants from the frequent rainfall. This particular rainforest experiences on average 19 minutes of rainfall six times every day. Some say it takes 20 minutes from the start of a rainfall for any water to reach the floor of the forest. The water that does reach the ground is purified as it permeates through rocks, minerals and plants. The Puerto Rico rainforest trail I traversed included a beautiful waterfall and pool at its base. The 1-mile-long trail out of the forest took us along water falling over rocks and shallow drops that fed into the impressive rainfall below.
OK, so what does all of this have to do with the construction industry? Today we use the term “sustainability” loosely and we often simply equate it to “green”. But only when you begin to appreciate the forces of nature can you truly understand what a sustainable setting is. No waste. No end to the supplies of energy and sustenance. The capture of rainfall without destroying the delicate ecosystems. These are all components of MBDC’s Cradle to Cradle life-cycle analysis certification concept.
In a Cradle to Cradle concept, an industrial system that typically "takes, makes and wastes" can actually create goods and services that generate ecological, social and economic value. William McDonough, one of MBDC’s partners, claims today’s product designers can look to nature for “industrial” nutrient cycling and use the abundance of the sun’s energy in today’s buildings and products.
So what is taking so long to realize that harvesting renewable energy through integration into a building’s envelope makes a lot of sense? Installing photovoltaic systems on a roof or wall surface takes advantage of a free source of energy. Likewise, tapping into the energy from the sun with a water-heating system or heat recovery system on a roof can augment the energy needed for heating water or air inside the building.
A rainwater-harvesting system integrated into a roof assembly can reduce a building’s dependence on a local water supply that is often strained because of climate changes. Once again, the water falling from the sky is free, whereas the water from your faucet has a price attached to it—not to mention embodied energy.
Designing building components that can be removed, disassembled, reused or recycled helps to reduce the solid waste stream and energy needed for replacement virgin materials.
In the systems mentioned above, a metal roof or metal wall assembly can achieve the noted benefits of sustainable design. The design flexibility of today’s metal-building components allows for a variety of aesthetic features and a variety of fastening, attaching and dynamic performance features. With high recycled content and the ability to be completely recyclable, metal-building components are an important contributor to today’s sustainable building design.
Much of this is simply rethinking how we can produce and use building materials and systems. It will take rethinking to make “sustainability” a household word. A walk through a rainforest can make you rethink a lot of how we do things in industry.
Scott Kriner is president of Green Metal Consulting Inc., Macungie, Pa., and a member of Eco-Logic's advisory board.
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We’re clearly in the most intense green revolution since the oil embargo of the 1970s. Some might think this frenzy of activity to reduce our impact on the environment is new and can only be addressed with 21st century innovation. My recent visit to the National Building Museum in Washington, D.C., quickly reminded me how wrong that assumption can be.
The Green Community exhibit at the museum provided an interesting look into the history of green practices that are common today. The quote that caught my eye was: “The human race is challenged more than ever before to demonstrate our mastery--not over nature but of ourselves.” I was surprised to see this was not a recent quote but one made by Rachel Carson in 1962.
I was reminded that many of today’s green solutions to climate, water and sustainable existence are nothing new to mankind. A timeline in the museum points out that in 80 A.D., the Roman Senate required water to be stored during dry periods. In 1510, Leonardo da Vinci designed a horizontal water wheel to prove the principle of water turbines. In 1690, Colonel William Penn required Pennsylvania settlers to preserve 1 acre of trees for every 5 acres that were cleared. In 1762, Benjamin Franklin led a committee to regulate waste disposal and water pollution. The first mechanical windmill water pump was invented in 1854. And in 1861, Professor Augustine Mouchot of France patented a solar pump.
It was also amazing to learn about the amount of waste cities around the world generate. The U.S. recycles approximately 32 percent of its trash, which translates into 4.6 pounds per capita. Americans discard 96 billion pounds of food each year. Restaurants and grocery stores throw out $30 billion of food annually. This incredible amount of discarded food was the basis for the formation of a national group called the Freegans. One mission of the Freegans is to salvage discarded food and provide it to food banks in cities across the country.
I left the museum with the feeling that we can do better in the building-construction industry regarding the innovation of sustainable products. We must remember in nature there is no waste. To be truly sustainable, our industry needs to create and build with products that do not end up as waste. There already are some products in other industries that actually mimic nature:
The idea of mimicking nature is referred to as biomimicry. There is biomimicry research and innovation occurring in the construction industry today. For example, there are self-cleaning coatings available that are based on the nanoscale bumps on a lotus plant’s leaves. The carpet industry has used biomimicry to develop alternatives to conventional adhesives. Researchers are learning how to modify building designs for thermal comfort based on studying termites, which can maintain constant temperatures inside a building no matter the outside temperature. Scientists are studying the web silk of spiders for possible applications in construction fibers or cabling. Other research has proposed adhesive glue from studying mussels, solar cells made like leaves and water harvesting from fog similar to how a beetle does it.
Where will tomorrow’s building materials come from? Will they have a lower impact on the environment than today’s materials? Where will we look to find the inspiration for these innovations? We certainly can learn from our predecessors about innovation. We can examine how necessity was the mother of invention.
We can also learn from nature. A closer examination of our environment can show how things naturally stick together, gather and distribute energy, cool, shed and retain water, insulate, provide strength, remain clean, repair and are reused. At the end of a product’s life in nature it often becomes food for another process in nature. This is a lesson in sustainable building practices, as well.
Tomorrow’s roof and wall assemblies will likely feature biobased sealants, adhesives, insulators, coatings, reusable attachment techniques and innovative new products. The end result should be a more sustainable design without compromising the structural and/or functional performance of the assembly. As the green community says, we have no choice but to Reduce, Reuse, Rethink and Recycle to sustain the use of components in the construction industry.
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