Building codes are where they need to be when it comes to resilience against natural disasters, according to a new report commissioned by the NAHB.
Each year, hurricane season reminds us that homes can be damaged or destroyed by the winds and rain that extreme weather events bring. Texas A&M University recently finalized a report that sought to determine whether the year a home was built impacted its resilience to natural disasters.
Home builders can have a complicated relationship with codes: Excessive regulations can make homes too expensive to build, but sensible regulations provide a framework that help builders construct homes that are safe and well-built.
In 2017, parts of Texas and Florida experienced heavy damage from hurricanes Harvey and Irma, respectively. To better understand building performance relative to the age of the structure, NAHB contracted with the Zachry Department of Civil Engineering at Texas A&M University to conduct a study to see if there was a correlation between the year a home was built and the amount of wind damage it sustained during a hurricane.
The report found that newer homes built to the International Code Council’s International Residential Code (IRC)—the residential building code used in 49 states that creates minimum requirements for one- and two-family dwellings—fared better than older homes in hurricane-force winds.
Prior to this study, anecdotal reports, including statements in the Federal Emergency Management Agency’s damage assessments and media coverage, suggested that homes built to the IRC performed well in both states. However, there was little empirical evidence to support those claims.
The study found that in both Texas and Florida, homes built to modern codes, defined as any edition of the IRC, were less damaged by hurricane-force winds than older homes.
During hurricanes Harvey and Irma, roofs and wall coverings were the most damaged elements of homes. Homes built before 2003 in Texas and 2008 in Florida, and therefore built to older codes, sustained more damage than newer homes. However, very few homes constructed after 2003 in Texas or after 2008 in Florida suffered severe damage to roof sheathing, wall sheathing and framing or total loss and collapse of those components. The IRC’s structural provisions ensure that the integrity of the roof framing and sheathing is maintained, and that wall structure and sheathing damage is minimized.
These observations demonstrate that building codes are where they should be and that adherence to the IRC has been effective in preventing excessive damage to homes during a hurricane. The NAHB will continue to advocate for reasonable and effective building codes and standards, encouraged by the conclusion that we are on the right track toward making housing safer for all Americans.
