The building environments that form and shape our respective response districts pose unique challenges to the day-to-day responses of fire departments and their subsequent operations at structural alarms. With the variety of occupancies and building characteristics present, there are definable degrees of risk potential with recognizable measures that must be taken.
Although each occupancy type presents variables that dictate how a particular incident is handled, most company operations evolve from basic strategic and tactical principles rooted in past performance and operations at similar structures. With any structure, regardless of its construction type, materials, occupancy classification, age or size, the majority of incidents requiring actual operation time occur when the structure is in use or vacant.
But what about the early stages of the life cycle of a building - when a company is called to respond to an incident at a building under construction or at a construction site? Fire department responses and operations at building and construction sites present unique circumstances and considerations that are not part of that day-to-day alarm response procedure.
During the construction process, building and construction sites represent the highest potential for fire, injuries and large-scale operations than at any other time within the life cycle of a structure. When completed, the building may have state-of-the-art detection and suppression equipment present, it may be compartmentalized and use the best fire resistive materials available. However, during the construction process the building represents a high-risk target hazard with the potential to stretch to the limit the capabilities and resources of any fire service agency.
Buildings can be classified within five fundamental construction types:
- Ordinary (exterior protected)
- Heavy Timber
- Wood Frame
These are represented in various forms and sub-classifications within the NFPA 220 Standard on Types of Building Construction, as well as within each of the Model Codes Standardization Council (MCSC) Recommended Types of Construction, and the three (3) Model Building Codes, UBC, BNBC and SBC.
Regardless of construction classification, during the construction process each building can be affected adversely by flame and heat impingement due to fires, weather and environmental conditions, improper or inadequate construction techniques and methods as well as substandard or inappropriate construction materials and system assemblies.
When referring to the broad range of building and construction sites, there are five general classifications for most projects:
- New construction
Although there are some overlaps, each project presents hazards that affect life safety, structural integrity and exposures. Projects within the renovation and rehabilitation areas may include vacant or abandoned structures that are transformed into new occupancy/use buildings, or can include older structures that are brought back to their original state.
Current development trends are those in which older structures of brick-and-joist construction typically are renovated into commercial shopping centers, apartments and mixed-use occupancies. In many instances, the building interiors are altered extensively to accommodate the design criteria and, in doing so, may alter the integrity of the structures.
Conversions usually involve change from one occupancy use to another. For example, a factory used for manufacturing is converted into arts and crafts shops or into a multiple-occupancy facility. Most sought after structures of this kind include the heavy timber building (New England Mill Type) as well as old, reinforced concrete frame or steel-framed factory or manufacturing structures.