Consumables
WHEN IS A NEGATIVE REALLY A POSITIVE?
Wednesday 08. April 2009 - CHOICE OF HOME BUILDING MATERIALS CAN HELP REDUCE GREENHOUSE GASES
When built with wood, a typical American home stores more greenhouse gases than the average car emits in a year.
Depending on the manufacturing scenario, wood wall studs, floor joists, and sheathing panels can be carbon negative, meaning that they remove and store more climate-changing carbon dioxide (CO2) from the air than is required to make and use them. As a result, wood-framed homes can play a positive role in helping reduce greenhouse gas emissions.
To save energy and be environmentally friendly, more homeowners are installing high efficiency furnaces, appliances and lights. However, many overlook how the homes structure contributes to energy use and greenhouse gas emissions.
A group of 15 leading universities and research institutions found that homes built with wood store significant amounts of carbon. The researchers also found that building a wood home takes at least 16 percent less energy than homes built with concrete or steel, taking into account raw material extraction, manufacturing, construction and eventual demolition and disposal.
“Its important for homeowners to reduce their energy use and carbon footprint in lights, heating and cooling, but they should also consider their building materials,” says Edie Sonne Hall, a greenhouse gas expert with Weyerhaeuser (NYSE:WY), a large forest owner and wood building product manufacturer. “Wood takes relatively little energy to manufacture, as most of the manufacturing is done by the sun through photosynthesis.”
Weyerhaeusers iLevel business analyzed its total carbon footprint, including emissions from all steps in the manufacturing process, and the offset from carbon stored in its wood products. They discovered that their wood building materials store more carbon over 100 years than are released in all aspects of making them.
As trees grow, they absorb CO2 and break it into carbon and oxygen molecules. They release the oxygen back to the air, and combine the carbon with other building blocks to form wood fiber. After harvest and manufacture into building products, the carbon remains in wood for the life of the building and beyond.
“Wood is unique among structural building materials in its ability to remove carbon from the air and store it long term,” adds Hall. “Locking up carbon now provides humans with the critical time needed to find alternative energy sources and other ways to put less CO2 into the air.”