A new study shows polyiso insulation can save tens of thousands of dollars in installed costs when compared to other roof insulation materials. The independent study, performed by Energy Services Provider Group (ESPG), analyzed the cost to insulate the roofs of standard retail and elementary school buildings.
When the minimum required ASHRAE R-value insulation is used, polyiso demonstrates a consistent economic advantage over extruded and expanded polystyrene. The retail building study showed installed cost savings of:
- $93,000 to $146,000 when polyiso is used instead of extruded polystyrene.
- $60,000 to $95,000 when polyiso is used instead of expanded polystyrene.
The elementary school study found installed cost savings of:
- $65,000 to $95,000 when polyiso is used instead of extruded polystyrene.
- $39,000 to $62,000 when polyiso is used instead of expanded polystyrene.
“Not only is polyiso the product of choice for long-term thermal performance, it also is the preferred product for reducing installed costs of the roof system,” says Jared Blum, president of the Bethesda, MD-based Polyisocyanurate Insulation Manufacturers Association (PIMA).
The study also assessed the financial impact of adding an extra inch of polyiso, exceeding the standard ASHRAE R-value requirements. The study found that a roof system using additional polyiso is still more affordable to install than minimum levels of extruded and expanded polystyrene while offering increased energy efficiency. The retail building study found installed cost savings of:
- $72,000 to $113,000 when higher levels of polyiso are used instead of standard levels of extruded polystyrene.
- $40,000 to $79,000 when higher levels of polyiso are used instead of standard levels of expanded polystyrene.
The elementary school study found installed cost savings of:
- $47,000 to 73,000 when increased levels of polyiso are used instead of minimum levels of extruded polystyrene.
- $27,000 to $51,000 when increased levels of polyiso are used instead of minimum levels of expanded polystyrene.
A computer model compared the costs of insulating typical elementary schools and retail strip malls in six U.S. cities: Atlanta, Boston, Chicago, Dallas, Denver, and San Francisco. The study examined the costs of installing polyiso, extruded polystyrene, and expanded polystyrene to meet minimum ASHRAE 90.1 compliance standards. (The ASHRAE 90.1 R-value standard for Atlanta, Boston, Chicago, Dallas, and Denver is 15. The minimum R-value for San Francisco is 10.) The roof systems also met all other applicable building codes. The research compared the cost to install an extra inch of polyiso - for an increased R-value - to the cost to install the minimum R-value of extruded and expanded polystyrene.
For further details about the study visit (www.polyiso.org) or call (301) 654-0000. This information was reprinted with permission from PIMA, the North American trade association that advances the use of polyiso insulation. For more information, visit (www.pima.org).
