Retrofit Improvements - Making Homes Safer in Disasters

Codes Research
Contact: Gary Ehrlich
[email protected]
Director, Construction Codes & Standards
(202) 266-8545

Approximately 80% of the housing stock in the United States was constructed prior to the development and adoption of the 2000 International Residential Code (IRC) and subsequent editions. The benefits of retrofitting these existing homes to improve their resistance to blizzards, earthquakes, floods, hurricanes, and wildfires exceed that of increasing code requirements for newer homes. Research shows newer homes built to the IRC perform well when subject to natural hazards.

NAHB’s Construction Technology Research Subcommittee worked with Home Innovation Research Lab to develop a series of two-page guidelines, listed below, illustrating techniques for retrofitting existing houses to improve their protection against natural hazards. 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.

NAHB and Home Innovation 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.

Gray shingles on a roof

During high wind events, roof shingles can be damaged or blown off the roof. Asphalt shingles can be selected and installed for high-wind environments.

Attachment of Shingles

Attachment of Shingles

During high wind events, roof shingles can be damaged or blown off the roof. Asphalt shingles can be selected and installed for high-wind environments.
Picture of rafters inside a home attic

Gable end walls are the triangle-shaped wall sections found at the ends of a pitched roof and run parallel to the roof rafters or trusses forming the gable. During a high-wind event, inadequately braced gable end walls are vulnerable to failure.

Gable End Bracing

Gable End Bracing

Gable end walls are the triangle-shaped wall sections found at the ends of a pitched roof and run parallel to the roof rafters or trusses forming the gable. During a high-wind event, inadequately braced gable end walls are vulnerable to failure.
White front door to a home
As an alternative to installing hurricane shutters on doors, impact resistant entry doors and sliding glass doors can be installed to protect against windborne debris.

Impact Resistant Doors

Impact Resistant Doors

As an alternative to installing hurricane shutters on doors, impact resistant entry doors and sliding glass doors can be installed to protect against windborne debris.
Sealing paper on a roof being installed
 A sealed roof deck uses an enhanced layer of underlayment between the roof covering (shingles) and roof deck (plywood) that is designed to better resist wind and rain.

Sealed Roof Deck

Sealed Roof Deck

 A sealed roof deck uses an enhanced layer of underlayment between the roof covering (shingles) and roof deck (plywood) that is designed to better resist wind and rain.
Wooden shingles on a home's roof

Wood shingles can be used on roofs in fire-prone areas, but they must be properly treated and installed.

Fire Retardant Wood Shingles and Shakes

Fire Retardant Wood Shingles and Shakes

Wood shingles can be used on roofs in fire-prone areas, but they must be properly treated and installed.
A two-car garage door
A garage door that is not rated to resist the local wind-load requirements can be reinforced, braced, or replaced. Aftermarket reinforcement kits are available to strengthen existing garage doors.

Garage Door Reinforcement

Garage Door Reinforcement

A garage door that is not rated to resist the local wind-load requirements can be reinforced, braced, or replaced. Aftermarket reinforcement kits are available to strengthen existing garage doors.
Large ice dams forming on a home's gutters
Ice dams can damage roof shingles and lead to water leaking into the attic and into the house.

Preventing Ice Dams

Preventing Ice Dams

Ice dams can damage roof shingles and lead to water leaking into the attic and into the house.
Siding being installed on a home
Select wind resistant cladding products and ensure they are properly installed to reduce the risk of wind damage during a storm.

Wind Resistant Exterior Cladding

Wind Resistant Exterior Cladding

Select wind resistant cladding products and ensure they are properly installed to reduce the risk of wind damage during a storm.
Flashing on a roof around a chimney
Deteriorated or incorrectly installed flashing at roof penetrations such as plumbing vents, chimneys, and skylights can allow rainwater to enter through the roofing that can damage the roof structure and interior finishes.

Flash and Seal Roof Penetrations

Flash and Seal Roof Penetrations

Deteriorated or incorrectly installed flashing at roof penetrations such as plumbing vents, chimneys, and skylights can allow rainwater to enter through the roofing that can damage the roof structure and interior finishes.
Hurricane shutters partially cover windows on a home
Several options are available to homeowners for protecting their windows and glass doors against windborne debris: impact-resistant glass, permanent hurricane shutters, and temporary storm panels.

Hurricane Shutters

Hurricane Shutters

Several options are available to homeowners for protecting their windows and glass doors against windborne debris: impact-resistant glass, permanent hurricane shutters, and temporary storm panels.
Hurricane ties holding rafters to wall framing
During a hurricane or other high-wind event, the connection between the roof framing and walls can fail, making the house susceptible to wind and water intrusion into the attic.

Roof to Wall Connection

Roof to Wall Connection

During a hurricane or other high-wind event, the connection between the roof framing and walls can fail, making the house susceptible to wind and water intrusion into the attic.