Lesson 3 – Sustainable Building Materials in Natural Building

Some examples of sustainable building materials include recycled denim or blown-in fiber glass insulation, sustainably harvested wood, Trass, Linoleum, sheep wool, concrete, panels made from paper flakes, baked earth, rammed earth, clay, vermiculite, flax linnen, sisal, seegrass, expanded clay grains, coconut, wood fibre plates, calcium sand stone, locally obtained stone and rock, and bamboo, which is one of the strongest and fastest growing woody plants, and non-toxic low-VOC glues and paints.

Vegitative cover or sheild over building envelopes also helps in the same.

Paper which is fabricated or manufactured out of forest wood is hundred percent recyclable,thus it regenrates and saves almost all the forest wood that it takes during its manufacturing process.

 

What Makes Concrete a Sustainable Building Material?

Resource Efficiency The predominant raw material for the cement in concrete is limestone, the most abundant mineral on earth. Concrete can also be made with fly ash, slag cement, and silica fume, all waste byproducts from power plants, steel mills, and other manufacturing facilities.

Durability Concrete builds durable, long-lasting structures that will not rust, rot, or burn. Life spans for concrete building products can be double or triple those of other common building materials.

Thermal Mass Homes built with concrete walls, foundations, and floors are highly energy efficient because they take advantage of concretes inherent thermal massor ability to absorb and retain heat. This means homeowners can significantly cut their heating and cooling bills and install smaller-capacity HVAC equipment.

Reflectivity Concrete minimizes the effects that produce urban heat islands. Light-colored concrete pavements and roofs absorb less heat and reflect more solar radiation than dark-colored materials, such as asphalt, reducing air conditioning demands in the summer.

Ability to Retain Stormwater Paved surfaces tend to be impervious and can block natural water infiltration into the soil. This creates an imbalance in the natural ecosystem and leads to problems such as erosion, flash floods, water table depletion, and pollution. Pervious concrete is a special type of structural concrete with a sponge-like network of voids that water passes through readily. When used for driveways, sidewalks, parking lots, and other pavements, pervious concrete can help to retain stormwater runoff and replenish local water supplies.

Minimal waste Concrete can be produced in the quantities needed for each project, reducing waste. After a concrete structure has served its original purpose, the concrete can be crushed and recycled into aggregate for use in new concrete pavements or as backfill or road base.

 

Why Concrete is a Healthy Alternative

Clean environments, free of dust, mildew and other pollutants can be achieved with interior concrete floors.
On average, we spend 90% of our time indoors—and most of that time we are in our own homes, according to Angela Dean, author of Green By Design.

Yet, we are increasingly using products containing volatile organic compounds (VOCs), in some cases creating indoor air quality that is 20 to 30 times more toxic than outdoor air, she warns.

The Healthy House Institute reports that indoor air pollution is the cause of about 50% of illnesses. Common sources of this pollution include outgassing from toxic paints and finishes, carpeting, manufactured wood products containing glues high in formaldehyde, dust mites, mold spores, mildew, and some cleaning products.

When it comes to poor indoor air quality, carpeting is one of the worst offenders. New synthetic carpeting can outgas over 100 different VOCs. And whether made of synthetic or natural materials, carpet is difficult to clean and becomes a haven for dust particles, pollutants, and bacterial growth.

Tens of millions of microorganisms can be found in a square foot of carpeting. Carpet can also be a major source of mold, especially if it becomes wet and the water isn’t removed completely.

Concrete floors, stained with nontoxic pigments, are a healthier alternative to carpeting because they do not emit harmful VOCs and are easy to sweep clean.

In fact, VOC emissions from concrete building products are much lower than those for most other building materials.

The use of natural lime-cement plaster wall finishes and concrete countertops can also significantly reduce total VOC concentrations inside a home.

Exposure to toxic mold in homes and buildings has been blamed for ailments ranging from headaches to severe respiratory infections and immune system disorders. Mold can thrive on any organic material, especially in warm, moist, humid conditions. In addition to carpeting, mold can feed on drywall and wood studs, joists, and wall sheathing. Concrete floors and walls won’t support the growth of toxic mold.

Recycled Materials

Sustainable architecture often incorporates the use of recycled or second hand materials, such as reclaimed lumber and recycled copper.

The reduction in use of new materials creates a corresponding reduction in embodied energy (energy used in the production of materials). Often sustainable architects attempt to retrofit old structures to serve new needs in order to avoid unnecessary development. Architectural salvage and reclaimed materials are used when appropriate.

When older buildings are demolished, frequently any good wood is reclaimed, renewed, and sold as flooring. Any good dimension stone is similarly reclaimed. Many other parts are reused as well, such as doors, windows, mantels, and hardware, thus reducing the consumption of new goods.

When new materials are employed, green designers look for materials that are rapidly replenished, such as bamboo, which can be harvested for commercial use after only 6 years of growth, sorghum or wheat straw, both of which are waste material that can be pressed into panels, orcork oak, in which only the outer bark is removed for use, thus preserving the tree.

When possible, building materials may be gleaned from the site itself; for example, if a new structure is being constructed in a wooded area, wood from the trees which were cut to make room for the building would be re-used as part of the building itself.

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