The presence of an airspace enclosed within a building envelope assembly is known to contribute to the overall thermal performance of the assembly. But, the actual R-value of an airspace can vary significantly depending on various conditions of use, such as the air-tightness of the assembly of materials enclosing an airspace.

• Research Report

• Educational Program

• Design Guide

  
  This guide reviews current technical knowledge and regulatory requirements to assist the designer in R-value characterization and limitations of use for airspaces within building assemblies for code compliance.

• Designer/Plan Reviewer Checklist

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