Ensuring Fire Safety in Building Construction
Effective building codes are critical for ensuring the fire safety of buildings.
We have all followed the recent tragedy in London, where a fire at Grenfell Tower, a public housing building, caused a great loss of life. Initial reports suggest that the newly installed cladding on the building’s exterior was combustible and may have contributed to the fire’s spread. Although this fire and its causes will be the subject of many future investigations, we should examine our current processes and consider how we can reduce the chance of such a disaster happening in the United States.
Developers that construct and renovate residential buildings must address and balance factors such as cost, energy efficiency, durability, and appearance. Although architects, engineers, code officials, and builders play important roles in selecting materials that provide effective fire resistance, building owners can also help improve their structures’ fire safety. As with any aspect of building performance, understanding the requirements, establishing clear expectations and goals, and being willing to consider alternatives will help everyone in the design and construction process understand and achieve their priorities. Building codes are minimum requirements established by states and localities for community safety. These codes, along with engagement by owners, developers, engineers and architects, and local building code officials, will increase building safety.
Much of this discussion applies especially to high-rise construction. High-rise buildings generally are constructed under the model International Building Code® (IBC®). Developed collaboratively with code officials, fire departments, industry representatives, designers, and the public, model codes are adopted and enforced by state or local governments. Multistory buildings have more stringent code requirements for fire safety because they house more people and have fewer exits compared to the number of occupants, which makes preventing the spread of fires and providing safe evacuation routes essential. Because building codes are subject to periodic revision, older buildings may not completely comply with requirements of current building codes, just as older cars may lack the required safety features of newer models.
Effective building codes are critical for ensuring the fire safety of buildings. Buildings constructed under the IBC® have more fire safety requirements than homes built under the International Residential Code®, generally because these homes are smaller and because the code requires bedrooms in these homes to have direct egress to the outdoors through windows or doors.
To address these requirements, the IBC® includes chapters on fire and smoke protection, interior finishes (with respect to combustibility), fire protection systems, and means of egress. Compliance with the building code, however, isn’t the only critical aspect. Rigorous planning, inspection, testing, and maintenance will help ensure that these fire safety features perform well over time.
Building codes classify construction materials based on their combustibility. The requirements for fire safety typically become stricter as the size, height, and capacity for the number occupants of the building increases. “When buildings get larger or taller they provide substantial fire department challenges,” says Rob Neale, vice president for national fire service activities at the International Code Council. “When additional factors — such as occupant awareness and mobility, the increased number of people in the building, and potential hazardous operations — exist, the building codes respond by increasing safety requirements.”
As a result, building codes for high rises emphasize fire-resistant construction, exits, alarms, and fire suppression technologies. Many of us have seen low-rise hotels or apartments during the early stages of construction, in which the concrete stairwells are among the first features constructed. In high-rise construction, the use of combustible materials on exterior walls is limited to the lowest floors unless the building is equipped with an automatic fire sprinkler system approved by the code official.
Many multifamily residential buildings up to six stories tall are constructed using wood framing, like single-family housing. The allowable building height and size are more restrictive for wood-framed multifamily buildings than for other types of construction because of the chance of rapidly spreading fire and the need for occupants to escape quickly.
Residential buildings constructed under the IBC® are required to have automatic sprinkler systems in the residential portion of the building. Sprinklers are intended to control fires so residents can safely escape the building. Modern residential sprinkler systems are designed to prevent fire flashover in the room where the fire starts to improve occupants’ chance of survival.
The best opportunity to maximize building performance while minimizing additional costs is during the project’s concept development and design phases. For example, the difference in cost between a high-performance product and the code-minimum version of the product may be only a few dollars. Compared with the cost of the basic item, the incremental cost of the improved performance may be quite modest.
Maximizing the fire safety of a building requires the full engagement of the project team, including the owner, designers, and builders. Questions for team may include the following:
- What are the fire requirements for the structure and building components?
- What are the local fire department’s capabilities for controlling or suppressing a fire in the proposed structure?
- Do the manufacturer, designer, and building code official all confirm that the selected materials comply with the design requirements and conform to the building code? The IBC® includes numerous performance standards to measure the flammability, toxicity, and durability of construction materials.
- Can the contractor confirm that it has the skills to install the materials according to the manufacturers’ requirements and code-mandated performance standards? How will the contractor verify correct installation of these materials?
- Are the building code provisions for this product scheduled to change soon? Does it make sense to comply with the future provisions, and if so, will community leaders and code officials accept that approach?
- What strategies (beyond those required by the building code) should we consider to improve the fire safety of buildings that are being renovated?
- Should we engage specialists with expertise in this topic?
- How will we verify that the products we selected are the ones being installed?
- Are there alternative materials that would improve residents’ safety? How would these alternatives affect the project’s cost and schedule?
- What are the maintenance requirements for the fire safety systems installed in the structure? Will these systems require additional staff or resources?
As we demand more of our buildings in terms of appearance, durability, energy efficiency, safety, structural performance, and cost, developers will need to carefully select materials and designs that balance these often competing goals.
We have an obligation to the families we serve to ensure that every building in our inventory is both high performing and safe, which won’t happen without significant and ongoing effort.