SIP up the Green Benefits

Posted on January 17, 2008
Tag(s): Energy, Green Building, Greenhouse Gas Emissions / Global Warming
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sip.jpg“SIPs, or structural insulated panels, are high performance building panels used in floors, walls, and roofs for residential and light commercial buildings. The panels are typically made by sandwiching a core of rigid foam plastic insulation between two structural skins of oriented strand board (OSB). They are manufactured under factory controlled conditions and can be custom designed for each home. The result is a building system that is extremely strong, energy efficient and cost effective,” according to SIPA (Structural Insulated Panel Association).

SIPs can cut home energy use by up to 50%! This fact makes it easy for SIP-built homes to qualify for an Energy Star rating by the U.S. Environmental Protection Agency (EPA). Benefits to homeowners who purchase Energy Star rated homes include: higher appraised value; they qualify for Energy Efficient Mortgages and Tax Credits; and the home is more durable and comfortable.

So, we know the panels provide excellent insulation and therefore reduce greenhouse gas emissions through energy conservation, but are the materials used to make the panels environmentally friendly? The answer is that they do have eco-friendly characteristics like: “the lightweight rigid foam plastic is composed of 98% air, and requires only a small amount of petroleum to produce. The foam insulation used in panel cores is made using a non-CFC blowing agent that does not threaten the earth’s ozone layer.”

The OSB used for the outer skin is typically manufactured in the U.S.A, and according to the Structural Board Association (SBA) has the following characteristics:

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3 Responses to “SIP up the Green Benefits”

  1. Anna Hackman on January 17th, 2008 3:01 pm

    I love the SIP concept. If any of the SIPs used Advantec, the better. Advantec is a OSB that laughs at the weather. (Great product for subflooing.) They also make it as sheathing instead of using plywood or regular OSB. I bet they make it for SIP skins too.

    I was wondering one of the SBA’s statement about OSB can be safely disposed of in a landfill. OSB has a resin (like glue) that holds it together. I am not sure every landfill would take this.

    When I tried to find recyclers for a renovation job for a client, the state recyclers would only take fresh unpainted, and unglued wood. They would not take plywood. I would be curious who takes OSB for recycling. It would be good information to have.

    Do you know if the all OSB to use phenol resin (slower off gasing formaldehyde)rather than urea-formaldehyde? Anna http://www.green-talk.com

  2. Panel Man on January 17th, 2008 4:31 pm

    According to the Florida Solar Energy Center, a 2,000 sqft house made from SIPs with EPS core, will use about 40 gallons of petroleum in product.

    Although energy savings can offset this in less then a year, 40 gallons is still being consumed.

    There are now options (which are slowly coming to market) for creating structural insulative foam, that is derived from a bio-based sources.

    This… is the true wave of the future.

  3. joyceb on January 17th, 2008 6:02 pm

    This is some additional information I found regarding core materials for SIPs (from Ecology Action):

    Straw Core SIPs are made from waste agricultural straw. They are renewable and recyclable, and the pressed straw core does not require a binder. On the other hand, straw-core SIPs offer less insulation per inch of thickness and are considerably heavier than other options; energy use in shipping is a significant consideration.

    Expanded Polystyrene (EPS): EPS is the most common SIP core material. It requires less energy manufacture than other options, and is more recyclable than polyurethane or polyisocyanurate. EPS foam is expanded with pentane, which does not contribute to ozone depletion or global warming, and is often recaptured at the factory for reuse.

    Polyurethane/Polyisocyanurate: Both of these materials offer greater insulation per inch of foam than EPS, are more resistant to thermal breakdown. However, polyurethane and polyisocyanurate are unlikely to be recycled. Polyurethane and polyisocyanurate use HCFC blowing agents, which contribute to global warming and ozone depletion. It will be great when SIPs are made with soy-based foam. Hopefully, we won’t have to wait too long.

    As far as Anna’s question goes, it is phenol formaldehyde that is in SIPs, but at very almost undetectable levels in the finished product.

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