Author(s): Angelo Verzoni. Published on September 1, 2017.

Danger: Construction

A recent spate of large and costly fires involving buildings under construction underscores the need for more widespread use of NFPA 241 to address a range of related hazards


On a warm summer morning, the smell of smoke still lingered among the masses of charred wood and twisted metal blanketing a large plot of riverside land in Waltham, Massachusetts.

Related Content

The Arson Issue:
Taking steps to protect buildings under construction against arson.

Visit the American Wood Council’s website for construction fire safety, which includes dozens of resources such as videos, fire safety manuals, and more.

Read NFPA’s April 2017 report, “Fires in Structures Under Construction, Undergoing Major Renovation, or Being Demolished.”

Read the March/April 2017 NFPA Journal article, “Burned Again,” reporting on fires in properties being built by AvalonBay in New Jersey.

Read the May/June 2017 NFPA Journal feature, “Hot Work, Safe Work,” on the lessons learned from the U.S. Chemical Safety and Hazard Investigation Board’s review of hot work incidents.

Sign up for new NFPA online training on NFPA 241.

A week earlier, the property, about 10 miles west of Boston, was occupied by five nearly completed apartment buildings containing more than 260 units, which were set to start taking tenants in the fall. But early on the morning of July 23, a massive fire tore through the complex, reducing most of it to rubble. Only concrete elevator shafts and a concrete parking garage remained intact.

The blaze spit embers like a wildfire, threatening properties thousands of feet away. “The embers that I saw flying by were softball-sized,” recalled Waltham Deputy Fire Chief Andrew Mullin. “We received reports of embers and debris up to a mile from the site … and numerous roofs that have damage.” Embers sparked a dumpster fire about a third of a mile from the site and a small structure fire about a quarter of a mile away, according to Mullin. About three weeks after the fire, investigators announced it was intentionally set and that they were seeking the public’s help in identifying the arsonist. Damage was estimated at $110 million.

The Waltham blaze was one of a series of large fires that have occurred in the last several months in buildings under construction in the United States. In August, a 118-year-old former mill in Colorado, which was being redeveloped into a restaurant and other businesses, was destroyed by a fire. Earlier that month, a fire ignited by soldering caused extensive damage to a historic building being renovated on the campus of the University of Vermont. In early July, a fire that was large enough to be detected by weather satellites in space razed a seven-story apartment building under construction in Oakland, California. In June, flames gutted a nearly completed apartment building in Boston. In April, a fire caused an estimated $40 million in damage to an apartment building under construction in Maryland. And in March, two fires less than a week apart roared through apartment buildings under construction in North Carolina and Kansas.

In five of these fires—the two in Massachusetts, and the ones in Maryland, North Carolina, and Kansas—a common thread was the buildings’ wood-frame construction, which relies on the use of structural wood members like two-by-fours coupled with “lightweight” or “engineered” wood components produced with glues and resins. (Wood-frame construction should not be confused with mass timber construction, which uses much larger, heavier slabs of engineered wood to build what are commonly referred to as “tall wooden buildings.”) Wood has been touted as a less expensive, longer-lasting, and more sustainable alternative to materials like steel and concrete. Wood-frame construction is widely used in single-family homes, and has also become common in larger buildings, many of them multifamily housing complexes up to five stories in height.

Lightweight wood has also been proven to burn, and fail, faster than traditional dimensional lumber, which is why it has been a safety concern of the fire service for more than 20 years. But others stress that questioning the building materials involved in these recent fires is only one step in addressing the problem. A more comprehensive approach, they say, considers the fire hazards presented by any construction site, regardless of the materials used for building.

An important tool for mitigating the fire hazards of construction sites is NFPA 241, Safeguarding Construction, Alteration, and Demolition Operations. The standard outlines measures to reduce the risk of fire in buildings under construction, as well as those being renovated or demolished. It requires building owners, who are tasked with implementing it, to designate a fire prevention program manager to make sure the correct fire safety measures are being followed during the entirety of a construction project. The 2018 edition of NFPA 241 is expected to be available later this year and will include several changes on the use of cooking and heating equipment and provisions for the use of temporary fire protection systems on construction sites. It will also include new measures allowing authorities having jurisdiction, or AHJs, to require site security when workers aren’t present for projects involving combustible construction over 40 feet in height.

Despite NFPA 241 being in existence for over 80 years, a failure persists among stakeholders to properly apply it, which is why experts feel there’s a need to increase education on the standard. To that end, NFPA and the American Wood Council (AWC) are both ramping up efforts to better educate stakeholders on construction fire safety resources including NFPA 241 in an attempt to reduce fires in buildings under construction.

Is wood the enemy?

After the two Massachusetts fires, local fire and public officials blasted wood-frame construction. The harshest words came from the mayor of Waltham, Jeanette McCarthy. “Construction by wood frame is idiotic. It’s insane,” she told Wicked Local, a community news website. Similarly, Waltham Fire Chief Paul Ciccone told Wicked Local that he would “rather see things built of noncombustible products.”

There is anecdotal evidence to suggest wood-frame construction, especially for multifamily residential buildings, is flourishing in parts of the country, including the Boston area. Data from the U.S. Census Bureau shows it is by far the most popular framing type for multifamily buildings—and has been for several years. Wood-frame construction made up 84 percent of the multifamily buildings constructed in the U.S. in 2016, according to census data. That level has remained steady over the past eight years at an annual average of roughly 86 percent.

Aftermath of a fire that struck a large apartment complex under construction.

Smoke + Ash A large apartment complex under construction in Waltham, Massachusetts, was destroyed by a July fire that caused an estimated $110 million in property damage. Nationwide, similar fires have recently leveled an array of developments under construction. Photograph: Bob Duval

As wood-frame construction dominates multifamily buildings, steel-frame construction is becoming less popular. From 2009 to 2012, it averaged 7.75 percent of the total multifamily buildings constructed annually; from 2013 to 2016, it averaged just 4.25 percent. The stable popularity of wood and the declining popularity of steel for these buildings means other materials, including concrete, are becoming more common, although census data is not available on those. Additionally, data from FP Innovations, a Canadian organization that researches the forest industry, suggests that multifamily residential buildings are getting bigger. In 2006, 18 percent of multifamily construction was four to six stories. In 2016, it was 37 percent.

While wood-frame construction poses a legitimate concern to the firefighters who may have to charge into burning buildings, experts like Allan Fraser, senior building code specialist at NFPA, stress that when a building is under construction, it’s the state of being under construction itself that puts it at the greatest risk for fire, rather than what it’s made of. In other words, the risk of a fire starting in a steel building under construction is equal to the risk of a fire starting in a wood-frame building under construction, Fraser said.

The numbers - Average annual number of fires 8,440 and average daily number of such fires nationwide 23

The best evidence of this are the devastating fires that have occurred in non-wood buildings under construction or being renovated or demolished. In 2007, two New York City firefighters died battling a blaze in the Deutsche Bank building, built in 1974. The steel-frame building was being torn down as a result of severe damage it received in the September 11 terrorist attacks.

When fires do start in wood-frame buildings under construction, though, the inherent strength differences between wood and a material like steel are what fuel the fire service concerns. During the early stages of construction, all buildings are vulnerable because most of the fire protection systems and code-required design features to isolate and contain fire have not been installed, said Ken Willette, first responder segment director at NFPA. “When firefighters are called to fight a fire in these buildings, they are confronted with a tremendous volume of fire that is attacking the skeleton of the building that keeps it upright,” Willette said. “When the building is wood-framed, and in particular lightweight wood–framed, the skeleton fails much quicker than in a steel-frame building, and this concerns firefighters—a collapse can occur suddenly and with little warning, possibly trapping them.”

Recent fires involving buildings under construction

Here & Gone Recent fires in buildings under construction or renovation include, clockwise from top right, a former mill building in Colorado undergoing conversion to a mixed-use development; an apartment complex in Raleigh, North Carolina; an apartment building in Oakland, California; and an apartment complex in Overland Park, Kansas. Photographs: bottom left: Newscom; all others: AP/Wide World

In response to the recent fires in wood-frame buildings under construction, the AWC, a trade association representing the majority of wood products manufacturers in North America, intends to drive traffic to its website on construction fire safety. The site, which includes videos, fire safety manuals, and more, was launched a couple of years ago for builders, regulators, and the fire service. Integral to those efforts is the recent creation of the Construction Fire Safety Coalition, which was formed to help increase education and awareness around potentially valuable tools including NFPA 241.

“The wood products industry recognizes the significance of these fires, and we feel that education is the best approach—getting everybody to be aware of the threat of a construction fire and making it a priority every day for everybody on the job site,” said Kenneth Bland, vice president of codes and regulations for the AWC.

Under construction, on fire

Wood or not, buildings under construction have a tendency to burn. A recent NFPA report, “Fires in Structures Under Construction, Undergoing Major Renovation, or Being Demolished,” found that from 2010 to 2014, there was an annual average of 8,440 fires in buildings under construction or being renovated or demolished. That’s nearly two dozen such fires every day. The blazes also resulted in an annual average of 13 civilian deaths, more than 100 civilian injuries, and over $300 million in direct property damage. The report contains no information on the building materials involved in these fires, but presumably it was a diverse mix of materials typically used in building construction.

NFPA 241 Stats

Fraser is optimistic that new training programs from NFPA on NFPA 241 will begin to drive those figures down. In September, NFPA plans to launch a three-hour online training program on NFPA 241, and in November, a three-hour on-site training will be given to the Tennessee Fire Marshals and Inspectors Association. “We will be doing more training for building owners, but we will also be training fire departments to go out and train building owners, because fire departments simply don’t have the resources to monitor construction sites on a continuous basis,” Fraser said. While adoption, enforcement, and implementation of NFPA 241 remains an AHJ responsibility, NFPA 241 places the ultimate responsibility for the day in, day out fire safety of the construction site on the building owner.

Fire rages in a large warehouse under construction.

Equal Opportunity Fire damaged a large warehouse under construction in Bethlehem, Pennsylvania, in August. Fires involving large apartment complexes under construction have dominated headlines, but construction fires are a problem for buildings across a range of occupancies. Photograph: Chris Shipley: The Morning Call

A key challenge to implementing NFPA 241 is finding and designating a fire prevention program manager with the right skills and expertise to do the job effectively. Not only does that person need to have extensive knowledge of NFPA 241, they also need to be familiar with the additional codes and standards it references—there are 19—and with specific construction operations that can be small parts of an overall project but can account for the biggest fire risk. Roofing is a good example, Fraser said. “It’s hot work. It’s dangerous work. It’s messy work,” he said. “Under those conditions, it’s relatively easy for an individual to forget a safety procedure. They may be roofing for two days, but one mistake and the building’s gone.”

Hot work safety is an important part of NFPA 241, which references NFPA 51B, Fire Prevention During Welding, Cutting, and Other Hot Work. But according to the NFPA report, other factors, such as cooking and heating equipment used by work crews, cause more fires in buildings under construction or being renovated or demolished. In fact, in the five-year span it examined, 27 percent of fires in buildings under construction, on average, were caused by cooking equipment; hot work involving a torch, burner, or soldering iron only accounted for six percent of the fires. For buildings undergoing renovation, heating equipment was the leading cause of fires, at 15 percent, and for buildings being demolished, intentionally set fires were by far the leading cause, at 42 percent.

Hot work receives a lot of attention in part because of a 2014 fire in Boston that was sparked by welding, killing two firefighters. In response to the tragedy, NFPA launched its Hot Work Safety Training program, and as of September 1, all workers performing hot work in Boston have to be trained and certified. Fraser said he hopes for the upcoming NFPA 241 trainings to “take off” in the same way NFPA’s hot work training has.

Notices of intent to make a motion, or NITMAMs, for the 2018 edition of NFPA 241 will be posted October 12. To follow the development of the next edition of the standard, go to the NFPA 241 Document Information webpage.

ANGELO VERZONI is staff writer for NFPA Journal. Top Photograph: Getty Images