When you impose a question of What is Green Building?, the answer is not specifically confined. The goals of green building design are profuse. Some of them are as follows:
> Minimize environmental impacts resulting from the extraction of coal, natural gas, and oil, including oil spills; the mountaintop removal mining of coal; and the pollution associated with hydraulic fracturing for natural gas.
> Reduce pollution of air, water, and soil.
> Mitigate global warming through energy conservation, reduction of GHG emissions, and carbon sequestration through biological processes, such as reforestation and wetland restoration.
> Protect natural habitats and biological diversity, with specific concern for threatened and endangered species.
ENERGY MODELING
As building designs are refined, it is relatively easy to examine tradeoffs using energy models of proposed buildings. Tradeoffs of wall design, window design, building shape, heating system selection, and other schematic design parameters are readily prepared in less than a day. More advanced energy models, which can examine detailed tradeoffs of such systems as daylighting or energy controls, take longer to prepare and interpret, but are still often worthwhile when compared to the future costs of energy use over a building’s life.
There is no longer the need for speculation in refining building designs to achieve energy efficiency. Energy modeling should be regarded as essential for green building design.Energy modeling uses computer software to analyze a building’s numerous thermal components, including the materials of the walls and the rest of the building envelope; the size, shape, and orientation of the building; how the building is occupied and operated; the local climate; system performance; and energy use over time.
USING WASTE FROM LANDFILLS
A main focus of green building waste management is to divert waste from landfills. One strategy to accomplish this goal is to include up-front planning during design, as when, for example, specifying materials to be diverted for recycling or reuse. Goals may also be set for waste diversion, either by weight or volume; provision for the collection, separation, and storage of recyclable waste; and
specifying the requirements for tracking and quantifying of waste to meet waste diversion goals. Over time, we expect increased efforts to prevent waste from even reaching a construction site. This might be accomplished, for example, through reduced packaging.
RAPIDLY RENEWABLE MATERIALS
Rapidly renewable means materials that grow naturally and can be harvested in a short number of years, such as the ten-year period defined by LEED. Examples include bamboo flooring, cork flooring, carpet fiber derived from corn, cotton insulation, natural linoleum, natural rubber flooring, soy insulation, straw bales for walls and insulation, strawboard cabinetry, wool carpeting, and wheatboard millwork and cabinetry. By using rapidly renewable materials, we reduce the depletion of materials that take longer to grow, such as wood from old-growth forests, or that derive from finite resources, such as plastics derived from fossil fuels. Choosing the right application is important for rapidly renewable materials. Bamboo floors, for example, may not be so durable in high traffic areas or in spaces with excessive moisture.
GREEN BUILDINGS AND NATURE
In considering building design, it is informative to return to our initial discussions of the natural forces from which buildings provide shelter—sun; air (wind, air leakage, drafts); water (rain, surface
water, subsurface water, and humidity); animal life (insects, rodents, birds, and others); temperature extremes; and contaminants (dirt, dust, mud, and airborne pollutants). It is vital to recognize these
forces, to respect them, to honor them. The site and building design can work to not only enhance the layers of shelter, and so improve protection from these elements, but also to offer ways in which
building occupants can choose contact with the natural world.
Rather than promoting artificial contact with nature through building weaknesses, such as the large windows through which people simply look outdoors, the design professional can seek deeper
ways in which to promote these connections on the site with all the tools of landscaping—vegetation, water, views, paths, fences, outdoor furniture, structures such as gazebos and pergolas, and
even unusual features like mazes and tree-houses. Perhaps the site can emphasize the sun with a sundial or water with a pool. Even urban buildings offer endless possibilities for meaningful, if modest, connections to nature.
MATERIALS WITH RECYCLED CONTENT
Use of materials with recycled content is encouraged. Preconsumer recycled materials are those that are diverted from the waste stream during manufacturing. Concrete is the most-used construction material. Concrete can contain recycled aggregate, which is crushed concrete after the
removal of reinforcement and other embedded materials. Concrete can also be specified to contain fly ash, which is a byproduct of coal combustion, or slag, which is a byproduct of smelting metal ore.
Previously used materials, such as concrete and steel, can be sorted and processed for reuse. Concrete can be crushed, washed, and graded to produce aggregate for use in the mixing of new concrete. Steel can be collected, separated from other recyclables with large magnets, compressed into large bales, and shipped to a processing plant where the metal is combined with small amounts of virgin steel for use in building products, such as structural steel. Steel fabrication uses a high quantity of recycled steel in its feedstock, reportedly rising above 90% in recent years.
> Minimize environmental impacts resulting from the extraction of coal, natural gas, and oil, including oil spills; the mountaintop removal mining of coal; and the pollution associated with hydraulic fracturing for natural gas.
> Reduce pollution of air, water, and soil.
> Mitigate global warming through energy conservation, reduction of GHG emissions, and carbon sequestration through biological processes, such as reforestation and wetland restoration.
> Protect natural habitats and biological diversity, with specific concern for threatened and endangered species.
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| image source: CS Team |
ENERGY MODELING
As building designs are refined, it is relatively easy to examine tradeoffs using energy models of proposed buildings. Tradeoffs of wall design, window design, building shape, heating system selection, and other schematic design parameters are readily prepared in less than a day. More advanced energy models, which can examine detailed tradeoffs of such systems as daylighting or energy controls, take longer to prepare and interpret, but are still often worthwhile when compared to the future costs of energy use over a building’s life.
There is no longer the need for speculation in refining building designs to achieve energy efficiency. Energy modeling should be regarded as essential for green building design.Energy modeling uses computer software to analyze a building’s numerous thermal components, including the materials of the walls and the rest of the building envelope; the size, shape, and orientation of the building; how the building is occupied and operated; the local climate; system performance; and energy use over time.
USING WASTE FROM LANDFILLS
A main focus of green building waste management is to divert waste from landfills. One strategy to accomplish this goal is to include up-front planning during design, as when, for example, specifying materials to be diverted for recycling or reuse. Goals may also be set for waste diversion, either by weight or volume; provision for the collection, separation, and storage of recyclable waste; and
specifying the requirements for tracking and quantifying of waste to meet waste diversion goals. Over time, we expect increased efforts to prevent waste from even reaching a construction site. This might be accomplished, for example, through reduced packaging.
RAPIDLY RENEWABLE MATERIALS
Rapidly renewable means materials that grow naturally and can be harvested in a short number of years, such as the ten-year period defined by LEED. Examples include bamboo flooring, cork flooring, carpet fiber derived from corn, cotton insulation, natural linoleum, natural rubber flooring, soy insulation, straw bales for walls and insulation, strawboard cabinetry, wool carpeting, and wheatboard millwork and cabinetry. By using rapidly renewable materials, we reduce the depletion of materials that take longer to grow, such as wood from old-growth forests, or that derive from finite resources, such as plastics derived from fossil fuels. Choosing the right application is important for rapidly renewable materials. Bamboo floors, for example, may not be so durable in high traffic areas or in spaces with excessive moisture.
GREEN BUILDINGS AND NATURE
In considering building design, it is informative to return to our initial discussions of the natural forces from which buildings provide shelter—sun; air (wind, air leakage, drafts); water (rain, surface
water, subsurface water, and humidity); animal life (insects, rodents, birds, and others); temperature extremes; and contaminants (dirt, dust, mud, and airborne pollutants). It is vital to recognize these
forces, to respect them, to honor them. The site and building design can work to not only enhance the layers of shelter, and so improve protection from these elements, but also to offer ways in which
building occupants can choose contact with the natural world.
Rather than promoting artificial contact with nature through building weaknesses, such as the large windows through which people simply look outdoors, the design professional can seek deeper
ways in which to promote these connections on the site with all the tools of landscaping—vegetation, water, views, paths, fences, outdoor furniture, structures such as gazebos and pergolas, and
even unusual features like mazes and tree-houses. Perhaps the site can emphasize the sun with a sundial or water with a pool. Even urban buildings offer endless possibilities for meaningful, if modest, connections to nature.
MATERIALS WITH RECYCLED CONTENT
Use of materials with recycled content is encouraged. Preconsumer recycled materials are those that are diverted from the waste stream during manufacturing. Concrete is the most-used construction material. Concrete can contain recycled aggregate, which is crushed concrete after the
removal of reinforcement and other embedded materials. Concrete can also be specified to contain fly ash, which is a byproduct of coal combustion, or slag, which is a byproduct of smelting metal ore.
Previously used materials, such as concrete and steel, can be sorted and processed for reuse. Concrete can be crushed, washed, and graded to produce aggregate for use in the mixing of new concrete. Steel can be collected, separated from other recyclables with large magnets, compressed into large bales, and shipped to a processing plant where the metal is combined with small amounts of virgin steel for use in building products, such as structural steel. Steel fabrication uses a high quantity of recycled steel in its feedstock, reportedly rising above 90% in recent years.
Civil Scholar is a Blog by Aravind Samala on Construction, Environment, Technology, Trends and Innovation.