Achieving Housing Resilience Through Retrofits
The increased number of significant natural disasters occurring over the past few years, coupled with ongoing concerns over the effects of climate change, have prompted action at every level of government to increase the resiliency of communities, infrastructure and buildings.
Research shows that homes built to the International Residential Code (IRC) perform well when subject to natural hazards. Although about 1 million new homes are constructed each year to current codes, approximately 80% of the housing stock in the United States was constructed prior to the development and adoption of the 2000 IRC, meaning the vast majority of existing homes in the United States could see increased resilience through retrofitting.
The benefits of retrofitting homes originally constructed to obsolete building codes or none at all to improve their resistance to blizzards, earthquakes, floods, hurricanes and wildfires far exceed the benefits that could be obtained from further increasing the already-stringent code requirements imposed on new homes by recent editions of the IRC.
NAHB's Construction Technology Research Subcommittee worked with Home Innovation Research Labs to develop Retrofit Improvements - Making Homes Safer in Disasters, a series of two-page guidelines illustrating techniques for retrofitting existing homes to improve their performance against natural hazards. Targeted at homeowners, each guideline highlights the benefits of implementing the practice, the hazards addressed, considerations to discuss with a builder or remodeler, and the incremental costs of implementing the practice.
Many practices are cost effective, especially when incorporated as part of routine maintenance or a planned home improvement project.
As the 2020 hurricane season ramps up, it is appropriate the first set of guidelines include several practices aimed at improving the wind resistance of existing homes:
- The guideline on attachment of shingles provides information on proper selection and installation of wind-resistant asphalt shingles as part of a reroofing project.
- Adding a sealed roof deck using enhanced underlayment can help minimize water damage if roofing materials are lost during a severe hurricane.
- Home owners who are concerned about debris such as tree limbs, trash cans, patio furniture, or roofing and siding materials from nearby homes that can be picked up and carried along by hurricane winds, hitting and breaking windows, can review the guidelines on hurricane shutters and impact-resistant doors.
Two other guidelines now available cover flashing and sealing of roof penetrations — a recommended practice in any part of the country where heavy rainfalls occur — and guidance on preventing ice dams for home owners in colder parts of the country interested in getting a head start on preparing for winter.
NAHB and Home Innovation Research Labs thank the International Code Council, Insurance Institute for Business and Home Safety, U.S. Department of Housing and Urban Development, and the Federal Emergency Management Agency for their assistance in prioritizing the selected retrofit practices and providing review of the technical content.
For more information on the retrofit series, contact Gary Ehrlich.