Fire Season

How codes are adapting to Wildland-Urban Interface
Rich Walker
June 20, 2016
COLUMN : Industry Watch | Markets & Trends

Suburban sprawl, where new neighborhoods impinge on fire-prone open grasslands, forests or brushy areas, has created a complex landscape known as the Wildland-Urban Interface. While these attractive neighborhoods offer views and access to nature, all are put at risk during a brush or wildland fire.

The landmark 2002 fire season served as the catalyst for a concerted effort to develop WUI codes and local regulations. But, according to Scripps Institution of Oceanography, extreme drought conditions, warmer weather and more frequent Santa Ana wind events have all contributed to increased wildfire activity and longer fire seasons each year, especially in Southern California. According to the National Interagency Fire Center, 2015 was much worse than 2002, with nearly 9.3 million acres burned as of mid-October. As of March 25, we have already seen 8,171 fires which have claimed a total of almost 888,000 acres, the NIFC reports.

Windows in particular are considered to be one of the most vulnerable components of a structure when exposed to WUI fires. The thermal shock of direct exposure to flames or the impact of airborne debris could shatter the glass, permitting burning brands or flames to enter the building, virtually assuring its destruction. However, many people also mistakenly believed that the window frame, especially if vinyl, was also susceptible to melting under direct flame exposure, allowing the glass to fall out.

Based on this misinformation, officials of the Rancho Santa Fe Fire District and San Diego County in 2001 kicked off a controversy by prohibiting vinyl-framed windows in homes in WUI zones, unless a cleared 100-foot buffer zone existed. An entire class of product—ironically one with government-recognized energy-saving characteristics—was threatened with exclusion from a large market segment.

Fortunately, cooler heads have since prevailed. Subsequent testing conducted at the University of California Forest Products Laboratory concluded that all window products failed when subjected to high heat levels and the performance is dictated by glass type, rather than by window type or the specific framing material.

Current WUI Codes

Today, WUI fire prevention and control have become more mainstream and science-based than the early panic-induced and questionable solutions.

For example, we have the ICC’s International Wildland-Urban Interface Code, currently in the 2012 edition—a model code intended to supplement the building and fire codes of local or state jurisdictions. It is designed to bridge the gap between enforcement of the International Building Code and International Fire Code by addressing wildfires.

The IWUIC is fully compatible with all of the I-Codes, including the IBC, International Energy Conservation Code and International Residential Code. As of April 2016, 16 states have adopted the IWUIC at least as a local jurisdiction option (10 western states; four Midwestern; plus, something of an outlier, Rhode Island).

On a state level, the most noteworthy code action has been the Wildland-Urban Interface Building Standard, Chapter 7A of the California Building Code, titled Materials and Construction Methods for Exterior Wildfire Exposure. Additionally, a July 1, 2015 supplement was added to the 2013 Title 24, Part 2.5, California Residential Code.

Today, such WUI fire codes, as well as authoritative guidelines including the Insurance Institute for Building and Home Safety “Best Practices Guide for Wildfire—Commercial Properties,” typically call for windows and doors with a 20-minute fire rating when tested according to referenced standards from UL, NFPA and/or ASTM.

This level of fire resistance is achieved by products certified to the North American Fenestration Standard with double-pane glazing, especially when made of tempered glass, with metal reinforcement in the sash interlock area (meeting rails), and doors of a specified minimum thickness.

Meanwhile, a new network of 64 mountaintop cameras operated by researchers at Scripps Institution of Oceanography, UC San Diego, offers a new opportunity for 15early detection of fire hazards in remote locations in Southern California and within the WUI. The web-based AlertSoCal system—the 21st century version of multiple fire towers with human observers—will better detect fires in real time before they spread.

These are just a few examples of the progress that has been made. While the inevitable summer fire season is still horrendous, we are at least more cognizant and better prepared than ever.

Rich Walker, who after 22 years of service to AAMA, announced his retirement from the position of President & CEO.