###Insulation cuts pollution and fossil-fuel demand
Insulation is one of the most important components of any environmentally responsible building because it reduces energy consumption and therefore pollution. More insulation means less coal is burned at the power plant, and less gas or oil is burned in a furnace.
In fact, with good design and appropriate levels of insulation, you can minimize (or even eliminate) the need for central heating and cooling in many buildings. This principle is demonstrated in all superinsulated buildings, including PassivHaus buildings.
In this sense, any insulation material is a “green” product. Green builders need to focus on choosing which insulation is greener or better for a particular application. A few considerations include:
When choosing an insulation material, consider how it will work with the rest of the wall, roof, and floor system—and also consider what additional functions, such as air sealing, the material might serve. Some types of insulation stop air movement and reduce heat flow while shedding water and allowing drying (the four functions of the building enclosure).
Here are a few issues to consider when pairing insulation materials and structural elements for maximum efficiency:
Because different types of insulation are made from different raw materials and are manufactured using different methods, their environmental impacts vary. These life-cycle impacts should be considered along with factors such as R-value, air-sealing ability, and cost.
Installation—a 4% mistake yields a 50% penalty
Poorly installed insulation will not achieve the energy savings that its rated R-value would suggest. A California study concluded that a 4% void in fiberglass batts resulted in a 50% decrease in insulation effectiveness.
The type of structural framing also affects the performance of insulation. Steel studs conduct heat much more readily than wood studs, so they create thermal bridging…