Safe Effective Affordable Retrofits

CCHRC is continuing to advance durable, low-cost options for retrofitting homes. In searching for an alternative to exterior foam board retrofits, we found that more vapor permeable exterior insulations could offer a more affordable option. This study uses our Mobile Test Lab to test several wall configurations for moisture performance.­

1. Our latest study of wall retrofits suggested that using cellulose as exterior insulation instead of foam board allowed for better moisture control within the wall. Because cellulose is more permeable to water vapor than foam, it is less likely to trap moisture in the wall. 

2. Another retrofit approach includes air sealing the wall sheathing by adding an air barrier without adding any exterior insulation. This wouldn't improve the R-value of the wall but would be less expensive than a full exterior insulation retrofit (such as the REMOTE wall) and would still save energy by reducing air leakage.

Both retrofit approaches avoid trapping moisture in the wall assembly while aiming to reduce the cost and complexity of retrofits.

This project will establish more background on these approaches and lead to new wall studies and retrofit reccomendations. It includes a literature review, modeling and interviews with contractors. A summary will be shared with stakeholders and inform future retrofit experiments.

 

Read the report here

Related Topics & Keywords: 

Projects

Designs for Rural Alaska Walls Monitoring CCHRC demonstration homes for efficiency and moisture infiltration several years after construction.
Structural Insulated Panels Structural Insulated Panels (SIPs) are prefabricated building materials used in residential construction in Alaska. This project prepared resources for homeowners who want to learn about SIPs, where they are used in cold climates, and considerations for Alaska.
Energy Recovery Ventilators (ERVs) in Cold Climates Energy Recovery Ventilators (ERVs) are whole house ventilation systems that exchange stale indoor air with fresh outside air, recovering both heat and moisture from the indoor air to save energy. They have the potential to improve indoor air quality in a cold dry climate like Interior Alaska.
Thermal Mass Study Thermal mass is the ability of a material to absorb and store heat energy, which can be useful when it comes to cold climate housing. This project clarifies the role of thermal mass in housing and includes a literature review and energy modeling with IDA Indoor Climate and Energy (ICE) software.
Permafrost Foundations CCHRC worked with the U.S. Army Cold Regions Research and Engineering Laboratory to pair information on permafrost soils with optimal foundation designs.