BC - Chapter 1 - Building Construction
Loss of Structural Integrity. A building that maintains its structural integrity allows firefighters to more effectively attack an interiorfire.
Any building that collapses, under any conditions, has lost structural integrity.
Building Concept. The Building process begins when a developer or project owner perceives a need.
Once the building's concept appears on paper, it begins to be quantifiable, and the owner has the opportunity to evaluate and change the design.
Buildings are a composite of many diverse elements and systems that are designed with a purpose.
1st responders must understand the essential purpose behind building design and construction in order to predict how the fire will affect the structure occupants and contents and how best to mitigate those effects.
If renovation or remodel work is not carried out properly, unsafe conditions could result.
A building department should watch for any potentially dangerous changes such as removal or penetration of bearing walls, rooftop additions, or illegal remodeling that causes extreme hazards.
Financing= When the initial design has been selected, the owner must secure financing for construction.
A financial institution providing the construction loan will have certain requirements which may include a market analysis to evaluate the project's economic feasibility: -Land surveys -Preliminary budgets -Soil reports
Renovation and Remodeling. Permits for building renovation and remodeling are also included in the building permit process.
A jurisdiction may not require that plans be submitted for minor renovations; however, an inspector will determined whether the works was completed in an acceptable manner.
In the case of large projects such as a high-rise building that will take many months to construct, the building department may issue a permit for the initial phase of work so construction can begin while the final design details are being completed.
A permit may be issued for the foundation so that the excavation and construction can begin, thus saving both time and money.
Building codes impose restrictions on designers that may conflict with their creative intentions.
All designers have an ethical and legal responsibility to provide a safe end product.
Professional Design. The design and construction process is a serious and expensive undertaking.
An architect will use BUILDING CODES relevant to the jurisdiction as a primary resource when choosing major building aspects and eliminating alternatives.
Automatic Fire Suppression Systems. Inclusion of fire protection systems, especially an automatic sprinkler system, will affect the planned building design.
An automatic fire protection system, is the first line of defense in many buildings. Such systems can constrain fire growth and notify emergency responders.
Water availability is an essential consideration in the design of fire protection systems. The primary concern is the water quantity needed for the fire protection system's FLOW RATE
Any requirements that are not provided or supplemented by the existing infrastructure will add to the cost of the project; the developer may bear those costs or share them with the local community.
Where required, the area of refuge must be equipped with two-way communication so occupants can call for assistance.
Area of refuge may include arrangements such as stairway landing in a smoke proof enclosure, balcony located adjacent to an exterior stair, and protected vestibule adjacent to an exit enclosure.
Green design can have an indirect effect on fire fighting.
As a benefit, it is also possible in some cases that a fire can be so starved for oxygen that it burns itself out.
Occupancy and use are often addressed in model codes because they affect the FUEL LOAD, which in turn influences fire behavior within the structure.
As a general rule, greater quantities of fuel or highly volatile fuels will generate a higher HEAT RELEASE RATE.
Aesthetics and Culture. Although normally of little interest to the fire service, AESTHETICS, or the art in building design, is a major force in architecture.
As with other art forms, architectural styles are subject to change over time and are influenced by the communal environment.
Economics-Based Construction Variables. Funds often determine a building's overall appearance and size.
Available tax dollars, however, may force the architect to design a less costly facility by reducing or eliminating other spaces such as the library or music instruction rooms.
Documentation and Bids. When financing has been secured, the building's engineering design can proceed.
Bids are received from subcontractors who will perform specialized work, such as installing electrical wiring, and contracts are signed.
Materials= Some buildings may be designed using predesign prefabricated components and techniques.
Other buildings involve unique architecture and newly developed methods and materials.
If a building official rejects a proposed building design, an architect may appeal the decision to the BOARDS OF APPEALS.
Building codes provide an appeals process to resolve difference in interpretation of the specific code provisions or to review an alternative means of compliance.
Other Variables. Buildings are designed to provide people and their property with security from outside forces.
Buildings also provide stability and privacy for the activities carried out within a society, such as in office buildings and factories.
History of Building Construction. Because each building type reacts to fire conditions in a different way, the firefighters ability to recognize configuration features and component pieces of a structure is critically important.
Buildings may appear drastically different or be camouflage to look similar despite differences in age configuration and construction materials.
Common building designs must meet a wide range of engineering varibales.
Buildings that defy convenctional planning and may require special resources in case of an emergency including: -The golden gate bridge -Willis Tower, formerly the Sears Tower -St. Louis Gateway Arch.
Building Code Requirments. A building code is a body of law that determines the minimum standards that buildings must meet in the interest of community safety and heatlh.
By adopting model codes, government entities do not need to write their own complex documents to provide a fundamental degree of uniformity among jurisdictions. Model codes are not intended to address all features unique to a jurisdiction, so the AHJ may amend a model code through appropriate legislation to sir local conditions.
Community Fire Defense. Conflagration
Conflagration are large, uncontrollable fire covering a considerable area and crossing fire barriers such as streets and waterways. For example, forest fires can also be considered conflagrations.
Aesthetics frequently clash with fire safety concerns.
Converserly, the architect may leave piping and other mechanical equipment exposed for visual interest.
Buildings can take on cultural, as well as functional characteristics.
Designers strive for building designs that are appealing, confortable, and enhance human endeavors.
Configuration of Internal Spaces. The configuration of a building refers to its general shape or layout.
Designers tend to focus on the stucture's non-fire functionality and visual appeal. Design choices can significantly affect fire behavior and the response of building elements to a fire.
Gentrification. Older neighborhoods sometimes undergo gentrification in which older properties are extensively rehabilitated to satisfy the desires of a modern real estate market.
During renovation for gentrification, the effects of aging can be negated, although other problems may be discovered.
Electrical systems are essential to all modern buildings.
Electrical systems should also include a provision for emergency power that is protected from fire and highly unlikely to fail as a backup system.
Exposures and Fire Spread Factors. An exposure can refer to any number of surfaces that may be ignited or damage by the heat of an external fire.
Exposures includes structures and other objects, such as fuel storage tanks.
Building Permits= Before a building is constructed, a government unit, such as a city, county, province, or state, typically requires a BUILDING PERMIT to be issued.
Fire officials may be actively involved in the permitting process in some jurisdictions.
To the firefighter, building failure usually equates to structural collapse.
Fire spread through a fire-rated barrier is considered a failure. The unsatisfactory performance of a fire protection system is also a failure.
Existing Infrastructure. Public utility availability must be considered early in the design process.
For a large project, such as a residential subdivision, it may be appropriate to construct or enhance a sewer treatment facility.
Geographic Information Systems. Geographic information systems (GIS) technology is another means of obtaining, analyzing, and using data based on a specific location.
Graphic representation of resource response within a jurisdiction is a powerful application of GIS.
In cases where building codes allow ADA-inaccessible structural features, such as stairs, alternate protection must be made available, such as an AREA OF REFUGE where a person may wait safely until further assistance or instructions are available.
However, Areas of refuge is NOT REQUIRED in BUILDING equipped WITH an AUTOMATIC SPRINKLER SYSTEM.
In some juridictions, the fire authorities have legal authorities to review building plans.
Identifying and correcting problems before construction starts improves efficiency and cost effectiveness.
Many building codes quantify common sense requirements.
In addition to supporting its own weight, the structural system must be able to withstand environmental forces common to the area such as wind, snow, and earthquakes.
Design Deficiencies. Building codes are limited in their scope because codes cannot address every situation, codes are subject to political processes and interests, and codes can only provide a baseline level of protection.
In addition, a code may not provide an adequate level of safety, or compliance with the provisions of a code may not be possible.
Climate. Building heating and cooling requirements are determined by the reigion's historical temperature variations.
In all climates, insulating materials increase the structure's energy conservation.
Building Use. A building may be designed to meet the minimum requirements of the intended functions and not include significant adornments. A building's end use also dictates more subtle requirements.
In hospitals, the nurses's station is centrally located so the staff can observe the corridors and have a minimum travel distance to the patient's roooms.
Despite the longstanding awareness of the risk and principles of fire transfer, exposure fires remain a significant problem, especially in older urban environments with closely spaced combustible construction.
In modern suburban communities, building-to-building fire spread has been reduced as a result of code requirements including greater separations between buildings.
The owner may contract with a single firm to undertake both the building's design and construction. Such an arrangement is known as a DESIGN-BUILD.
In other cases, separate contracting and design firm may affiliate through a joint venture for a particular project.
Depending on the extent of the renovation, the owners may have to bring the building to current code.
In some cases, planned renovations may violate the provisions of a building code.
Tracking permits is particularly useful in the construction of large structures.
It is impractical to track a large number of projects, such a smaller building such as single-family dwellings, through the permit process.
Over time, many building undergo one or more changes in occupancy type.
More than a simple change in decoration and contents, this is a change to a building's overall use.
Natural terrain and developed terrain features will also affect the features of a completed building.
Natural and developed terrain features may complicate access by emergency responders such as steep slopes, rivers, and setbacks.
Construction technology is continually evolving.
Newer buildings may use technology that may not be fully tested or include unexpected hazards.
In some cases, a building may be exempt from current code requirements.
Occupancy changes may not be required to comply with current codes if the new occupancy classification is considered to be a lesser hazard than the original use.
There are only three primary strategies (modes) in a fire incident: offensive, defensive, and transistional.
Offensive strategies addresses: -life hazards -structural stability -Risk (benefit outweighs risk)
Life safety codes require that specific types of structures include fire and smoke resistant features.
Often equates to a longer time span between ignition and the development of an environment immediately dangerous to life or heatlh.
Energy Conservation (Green Design). Effort to increase the energy efficiency of structures and their components materials is known as GREEN DESIGN.
Other efforts include decreasing use of electrical power and water.
Fire loss management is systemic and includes many factors including life safety, engineering, and administrative controls to protect community resources.
Properly applied loss management activities generate benefits before and after a fire.
Significant portions of build codes are also devoted to fire safety because buildings include many features that affect fire behavior.
Provisions address elements such as fire resistance, means of egress, exposure protection, and occupancy separation.
Inspection and Testing. Knowledgeable inspectors must work closely with architects and contractors during construction.
Seemingly minor changes to an architect's or engineer's plans may directly cause or contribute to structural failure.
In 1990, the Americans with Disabilities Act was signed in law in the US.
The Act requires the removal of architectural barriers and the addition of other features to provide accessibility for persons with recognized impairments.
Construction Type. First the insurance industry, and then model building code publishers, recognized that fire behavior differed based on a building's features, and began to classify buildings by their construction type.
The IBC establishes numerical designations for a variety of construction types.
Fire Fighting Strategy. Building construction types influence the strategies that will be effective at a structural fire.
The building's exterior appearance may not match the interior.
Design Principles. During the concept phase, the variables may be discussed in terms of DESIGN PRINCIPLES.
The design principles of a building include many subcategories that influence the building's final appearance in addition to construction techniques and safeguards against structural failure.
Building construction methods and practices that resist fire and smoke spread are much more effective at preventing FIRE SPREAD between structures.
The earliest building codes were developed to prevent future conflagration from destroying whole neighborhoods or large sections of a city.
Age of Construction. All new construction is a product of its place and time.
The effects of age are not uniform. When buildings become obsolete and unmarketable, they frequently become a target for arson or may be left to degrade with weather and time.
The architect cannot address all design considerations presented by the owner.
The final building design always involves a balance of what is wanted, what is needed, and what is practical.
Engineering specialties = In addition to architecture, the major engineering specialties required during building construction include civil, structural, mechanical, electrical, and fire protection engineering.
The final consideration in the building design process is landscaping.
Fire department involvement in new construction testing and inspection provides the fire department with first-hand information from a PREINCIDENT SURVEY that is useful in PREINCIDENT PLANNING.
The fire prevention bureau should document fire protection system test results.
Fire temperature is one factor in determining whether a fire will progress to an exposure.
The flame's height and width are also relevant.
Preincident Planning in Building Construction. The building permit process is a resource that can be used by firefighters to develop knowledge of building construction in their jurisdiction.
The information can then be shared between fire companies and with the fire prevention bureau.
Life Safety Codes. Many safety codes are developed in reaction to catastrophic incidents.
The most prominent of these come from the NFPA and OSHA. The United States Fire Administration (USFA) maintains a national map that indicates location and frequency of fire fatalities.
Fire Spread
The movement of fire from one material (source) to another (exposure). May occur within a compartment or across a break.
Construction. The construction process requires coordination and scheduling.
The need for coordination also extends to suppliers, who need to know when materials will be needed at the job site.
The Design and Construction Process. The building's design and construction, is a process that begins as an idea and ends with a substantial structure.
The process may take weeks or years and requires many resources including legal expertise technical knowledge financial resources, management skills, creavtive.
Cutting costs may also lead to difficulties during an emergency.
The rationale for the decision may be that the lobby decor is visible and marketable while the generator is hidden from view and, presumably, will be used infrequently.
Buildings are diverse.
The reasons behind building design features may shift with time, availablility, and utility.
Heat Transfer. Fire spread is often expressed in terms of HEAT TRANSFER through two methods: CONVECTION, and THERMAL RADIATION.
The third method of heat transfer, conduction, is not usually considered a factor in spreading fire between buildings.
Building Site Properties. Engineering-based variables must take into consideration the features of the building site itself.
The type of foundation used will be determined partially by the soil's strength, resistance to strain, and stability.
Modern design methods allow more efficient techniques, resulting in less material being used for similar structural members.
These more slender and lighter structural members are structurally sound under normal climate and seismic conditions; however, under fire conditions, they may fail more quickly than older, heavier supports.
A primary hazard of green designs is the tendency of components to increase the combustibility of the overall building.
These structures are also designed to minimize heat loss, and as a consequence, they tend to hold the heat from a fire inside the building and may make ventilation more difficult.
Buildings must have a minimum number of exits based on the expected occupancy capacity and classification.
This aspect can be difficult to plan, based on fluctuations in the uses of the structure.
Some jurisdiction may adopt and use codes developed by the NFPA.
This code is often adopted by a governmental agency with a specific area of responsibility, such as a state health department.
In Canada, a widely used building code is the National building Code of Canada.
This document is a model code and is adopted or adapted by most of the provinces and territories in Canada.
Advantages of Older Construction. Structures built before computer aided design (CAD), were often designed with greater structural mass than was absolutely necessary.
This greater mass often results in greater structural stability under fire conditions.
The most widely used model building code in the United States is the INTERNATIONAL BUILDING CODE (IBC) published by INTERNATIONAL CODE COUNCIL.
This interdependence underscores the desirability for building and fire officials to work together in applying and enforcing building and fire codes.
A technique known as FAST-TACK CONSTRUCTION may be used to shorten the construction time by overlapping the design and construction phases.
This method can greatly reduce total construction time, making it attractive to owners.
Investment of Wealth. When buildings are constructed without a known occupant, they are referred to as SPEC BUILDINGS.
This type of construction is often developed primarily as an investment rather than to meet specific needs.
Defensive strategies address: -volume of fire -structural deterioration -risk (risk outweighs benefit) -structural conditions
Transitional strategies include all strategies that include a change in either direction between an offensive or defensive focus.
A building permit is obtained from the local building department.
Unusual designs or circumstances may require the use of compensatory measures or equivalencies rather than strict compliance with a prescriptive code.
Design-Caused Structural Failure. Depending on the structure's intended purpose, structural failure can be caused by any number of factors including unplanned loads and design flaws.
Unwillingness to spend additional money may entice a building owner to continue work without the necessary permits at any phase of work, but primarily during renovation.
The timing of some construction phases may affect the fire department.
Water supply and road work may be delayed during cold weather conditions, but the builders may continue constuction.
Building System Failure. Modern building function as total systems to provide a healthy, productive and comfortable environment using complicated systems.
Well-designed building systems utilize provisions to prevent the spread of COMBUSTION products, including such measures as smoke detectors to initiate the shutdown of units or to operate dampers in ducts.
In many cases, the actual construction type is not obvious, or multiple construction types may be used in combination.
When a building encompasses multiple construction classifications, the building should be considered to meet the lesser construction classification.
The fire ratings and life safety features of one occupancy type may not address the needs of another.
While not optimal, a change of occupancy may also be discovered when a fire or building inspector visits the property for a routine inspection. Communication is essential in this process.
In the WILDLAND/URBAN INTERFACE, fire can travel in either direction between the built and unbuilt environments.
Wildland/urban interface codes now address these exposures by regulating types of roofing and siding materials, and require the creation of defensible space through fire-resistant vegetation.
Thermal Radiation
the transfer of heat energy through space by electromagnetic waves.
Convection
usually involves the transfer of heat energy through the movement of hot smoke and fire gases.