in confined spaces. It is already used in refrigerators
and historic building renovations. These insulation
A Fiberglass Batt and a Vacuum Insulation
panels could be used in exterior doors, ceilings, and
Equal R Values
floors in manufactured homes, floor heating systems,
commercial building wall retrofits, and attic hatches
Building Envelope Embodied Energy
The complexity of calculating embodied
energy has given rise to a wide range of estimates.
Recently, an extensive consortium of 15 research
institutions (the Consortium for Research on Renewable Industrial Materials [CORRIM]) was formed to
examine the environmental and economic costs of building materials from tree planting to building
Results show that the building's embodied energy equals about 8 to 10 times the annual
energy used to heat and cool it and that the GHG emissions range from 21 to 47 metric tons over the life
of a house. The best way to reduce this significant embodied energy in a building is to salvage and reuse
materials from demolished buildings, even considering the extensive cleaning and repair often required of
the salvage materials.
The building design, size, regional material sources, and framing material selection all greatly
affect the embodied energy and GHG emissions. The CORRIM compared two house designs (wood framed
versus concrete or steel framed) and found that for the same amount of living space, a wood frame house
contains about 15 percent less embodied energy and emits about 30 percent less GHGs than does either
a concrete frame or a metal frame house.
Other studies in this area have reached similar conclusions.
The GHG footprint of building materials depends on many factors. This complicates the setting
of green building standards, and means that optimizing the appropriate mix of low GHG building materials
will likely be determined on a project specific basis. For example, wood is a renewable material that can
be obtained from sustainably harvested sources and can store carbon that would otherwise have been
emitted to the atmosphere as CO
, and can be engineered to further reduce the amount of harvested
timber required. Concrete can reduce operating energy consumption by providing thermal mass to buffer
Towards a Climate Friendly