December 15, 2010


Exterior insulation retrofit is a reasonable step if a recladding of the building is already being done for aesthetic or ongoing maintenance reasons. This paper presents many of the lessons learned from superinsulation retrofit experiences, including overall enclosure strategies, such as air barriers, drainage planes, and moisture control. Several case-specific solutions to particular problems are described, including exterior air barrier approaches, wall sill replacement, and several approaches dealing with window penetrations. In addition, detailing recommendations and economic analysis of these measures are presented. Hygrothermal simulations were run to evaluate the changes in sensitivity to moisture intrusion due to these retrofit measures.