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Title: New Whole-House Solutions Case Study: Exterior Rigid Foam Insulation at the Edge of a Slab Foundation, Fresno, California

Exterior rigid foam insulation at the edge of the slab foundation was a unique feature for this low-load, unoccupied test house in a hot-dry climate and may be more appropriate for climates with higher heating loads. U.S. Department of Energy Building America research team IBACOS worked with National Housing Quality Award winner Wathen-Castanos Hybrid Homes, Inc., to assess the performance of this feature in a single-family detached ranch house with three bedrooms and two full bathrooms constructed on a slab-on-grade foundation in Fresno, California. One challenge during installation of the system was the attachment of the butyl flashing to the open framing. To solve this constructability issue, the team added a nailer to the base of the wall to properly attach and lap the flashing. In this strategy, R-7.5, 1.5-in.-thick extruded polystyrene was installed on the exterior of the slab for a modeled savings of 4,500 Btu/h on the heating load.
Publication Date:
OSTI Identifier:
Report Number(s):
Research Org:
EERE Publication and Product Library
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B) (Building America)
Country of Publication:
United States
DOE/GO-102013-4052; NREL/FS-5500-60138; October 2013; HVAC; Space conditioning; Ductless; Distribution; transfer grille; Commissioning; Heat pump; Hot-Dry Climate; Simplified; residential; residential buildings; Building America; IBACOS