Ways BS 7974 in Enhancing Fire Safety in the Buildings and Structures - Term Paper Example

Heading: BS 7974 Building Code Your name: Course name: Professors’ name: Date Part 1 Introduction With the increasing number of fire accidents in the United Kingdom, it is vital that building code is strictly enforced. The building code provides guidelines to engineers and architects on how to design and construct buildings that are safe to occupy; and which allow easy movement and evacuation of occupants in case of fire outbreak. The code of practice also guides on the activation of fire control and alarm systems, and installation of fire detection systems. Besides, it provides direction on fire service involvement and assesses the rate of build-up of fire-fighting fire service’s resources. Therefore, this paper illuminates on ways in which BS 7974, as a building code, can be applied in the enhancing fire safety in the buildings and structures. To successfully do this, the paper intends to use the London City Hall, as an example of building, to assess the use of the code in its design and construction as regards fire safety. Understanding BS 7974 Building Code This code of practice offers an outline for the development of logical method in the design of buildings by applying safety engineering approach, which is based on the use of engineering and scientific standards to protection of property, people, and environment from fire damage. For a majority of building in the UK, the prescriptive recommendations on design in the present guidelines and codes as provided in BS 5588-0 can be found to be sufficient, but this code may be applied in the assessment and development of fire safety proposals in engineering. This approach can consider the total fire safety package may often offer a more basic and economical explanation than the prescriptive method to fire safety (Christian 2003, pp. 4-20). Furthermore, fire engineering safety approach is beneficial in many ways. The application of the BS 7974 is instrumental providing a designer with a restricted mechanism to fire safety design. It can also enable one to compare optional designs of safety levels. Moreover, the code of practice offers a foundation for the selection of suitable fire protection systems, as well as providing opportunities for inventive design. The code is also instrumental in the provision of information on a building or structure fire safety management. Since fire is a totally complex phenomenon with scarce information on it, the practice intends to offer an outline for elastic but official mechanism to fire safety design, which can be readily evaluated by approvals bodies. It is worth noting that the code of practice is aided by a number of Published Documents (PD) that possess information and guidance on how to conduct detailed analysis of particular fire safety engineering aspects. Notably, the code of practice offers a way of determining acceptable levels of fire safety economically, and without any unessential restrictions on building design aspects (Chow 2009, pp. 152-160). It also gives guidance on the assessment and design of fire safety procedures in buildings and structures. Besides, the code of practice is imperative in the provision of structured method of evaluating the efficiency of absolute fire safety system in order to achieve design objectives. What is more, Chow (2009, pp. 152-160) maintains that BS 7974 building code is crucial because it gives a framework for and outlines the fire safety engineering philosophy. It also explains the standards that are involved in the use of the fire safety engineering philosophy of specific buildings. Imperatively, this building code is instrumental in the identification and definition of one or more fire safety design matters to be tackled by use of fire safety engineering. Furthermore, the code provides optional approaches to the prevailing guides and codes for fire safety, and allows departure effects from more prescriptive codes to be assessed. Most important, Christian (2003, pp. 4-20) says that the code is influential in the recognition of design objectives, which are attainable by different alternatives and complementary fire protection measures. In terms of the scope, the code gives an outline for an engineering method to the attainment of fire safety in buildings by providing guidance and recommendations on the use of engineering and scientific standards in safeguarding people, environment and property from fire. BS 7974 building code only applies to the appraisal of already existing buildings as well as the design of new buildings. Nevertheless, it does not offer particular guidance on the buildings that are utilized for large processing or storage of explosives, or flammable liquids. This is because the inherent danger linked to such buildings often requires special consideration that is beyond the document’s scope (Chow 2009, pp. 152-160). The framework for engineering approach to fire security outlined in this code of practice must be used in three major stages. The first stage is the Qualitative Design Review (QDR), which entails the definition of fire safety design, proposed potential design solutions, and performance measures developed (Christian 2003, pp. 4-20). Here, significant information is collected to facilitate assessment of the design solutions in the quantitative analysis. The second stage involves the quantitative analysis, where engineering techniques are employed in the assessments of the possible solutions acknowledged in the QDR. This stage is time-based analysis that uses suitable sub-systems to mirror the effect of fire on property and people at varied phases of its development. Here, limit state and steady state analyses can also be employed. The third stage involved is the assessment against criteria. This entails the comparison of production of quantitative analysis to the acceptance measures recognized in QDR to measure the proposals’ acceptability. Sub-systems (SS) In order to simplify the assessment of fire safety design, the process of fire safety engineering must be further divided into various sub-systems (Christian 2003, pp. 4-20). These sub-systems may be applied individually in addressing particular matters, or as a whole in handling the major fire safety aspects: SS1 concerns the start and growth of fire in the enclosure of origin. It, therefore, offers guidance on assessment of fire development and its size in the enclosure by considering four key stages that include pre-flashover; flashover; completely developed fire, and decay (Chow 2009, pp. 152-160). SS2 concerns the spread of toxic gases and smoke in and beyond the origin enclosure SS3 involves the structural response and spread of fire in enclosure of origin SS4 is about fire detection and activation of fire detection systems SS5 entails fire service intervention, and; SS6 addresses evacuation Part 2 Guidelines on design framework and fire safety engineering measures Here, the paper examines some of the guidelines necessary in the design outline and fire security measures. In relation to the London City Hall building, there are certain procedures and guidelines should be applied in order to maintain fire safety. In the architectural design of the building, some of the typical items were considered. To begin with, in terms of the building design, such issues as number of storey below and above the ground are worth considering in maintaining safety in case of fire outbreak. According to the BS 7974, others items considered include nature of construction; general dimensions; escape routes; normal circulation routes; interconnection and geometry of spaces; building’s internal sub-divisions; accessibility to fire appliance; fire service response time; fire-fighting access in the building; provision for evacuation of people from the building vicinity, and other factors that could influence the building’s fire safety design (Chow 2009, pp. 152-160). In terms of the building’s occupants, it was vital that their number and distribution is taken into account. The London City Hall’s engineers also considered occupants’ mobility; multiple or single use; state of wakefulness; social groupings, familiarity with building; presence of focal point or stage; key individual’s roles and responsibilities; and commitment to a particular activity. With respect to room or compartment, the building was constructed by taking into account such factors as, possible ignition sources, uncommon fire hazards like flammable liquids kept in offices; combustible contents; ceiling linings; ventilation systems; wall lining; ambient systems; fire load density; escape routes; and potential smoke and fire spread in the building (Chow 2009, pp. 152-160). Other factors that were considered, as per the building code, include planning constraints; any future changes in the building’s layout; extent and quality of continuing management control; and fire protection gadgets as specified by clients. Contacts for providing extra information were also considered in the building construction. According to Chow (2009, pp. 152-160), the code of building also demonstrates that the Fire Safety Engineering (FSE) has certain objectives that include life safety, loss control, and environmental impact. The construction of the London City Hall building was based on these FSE objectives. First, the life safety objectives considered in the building, which note that its fire fighters, occupants, and members of public who live or hang around the building can be put in danger by fire. Therefore, as per the provisions of the building code, the building must be designed in such a way that its occupants can leave it in considerable safety (Christian 2003, pp. 4-20). Secondly, the code required that the building’s firefighters can operate in the building without any unnecessary risk in assisting the evacuation, rescue and prevention of conflagration activities in case of an emergency. Furthermore, the building was designed in order to ensure that any collapse does not put people and fire-fighters that are around or within the building. With regard to loss prevention objective of the FSE, the impact of fire on the continuing feasibility of a business can be extensive, and consideration can be given to reduce damages to the contents of the building, ongoing business feasibility, fabric and structure of the building, and its corporate image. Environmental impact objective demonstrates that a conflagration that involves many buildings or the release of hazardous materials may have adverse effects on the environment (Grimvall, Holmgren & Jacobsson 2010, pp. 225-245). Therefore, FSE maintained that the construction of the building took note of the fire impacts on adjacent facilities and buildings; fire-fighting methods; and release of dangerous materials to the environment. ASET and RSET What is more, FSE requires that a life safety measures are vital in the design of a building. In order to ensure that occupants are safe, designers should establish that they can reach safety positions before the occurrence of untenable conditions (Babrauskas, Fleming & Russell 2010, pp. 341-355). One of the key considerations made is the determination of the time required for evacuation of the building occupants to a safe place. This time is dependent on various factors that relate to building, occupants, and rate at which untenable conditions occur. This is aimed at ensuring that all people leave the dangerous part of the building in considerable safety without aid. Further, this is meant to ensure that the available escape time is more than the time needed for escape; ASET (Available Safe Egress Time) and RSET (Required Safe Egress Time). Some of the tenability conditions involved here are loss of visibility; exposure to heat; exposure to irritant and toxic products; and structural failure (Babrauskas, Fleming & Russell 2010, pp. 341-355). Initiation and development of fire in enclosure of origin (SS1) Here, the building code focuses on the provision of guidance on assessing fire size and growth in enclosure of origin, and enclosures that the fire has consequently spread. It also gives guidance on special cases that include racked or stacked goods storage, malicious fires and fires outside the building (Chow 2009, pp. 152-160). There are certain factors that influence the design of fire safety for any building that include building design, possible ignition sources, location, environmental effects, arrangement and distribution of combustible materials, kinds of combustible materials, and ventilation conditions. The building code characterizes design fire in relation to fire size, smoke production rate, fire duration, heat release rate, time to main events like flashovers, and the rate of production of toxic substances. In relation to the London City Hall, the code holds that the design fire must be based on the objects in occupancy. Nevertheless, whereas the heat release rates for most of the objects are known, it is almost impossible to say that that fire will comprise of an established amount of materials. Further, it says that a design fire can be a steady state fire with a consistent heat production or time-reliant developing fire. A developing fire is assumed when evaluating time to main events like loss of tenability, flashover, and operation of detectors (Stationery Office 2006 pp. 18-30). In terms of the building features, some of the factors that affect the development of fire include building’s geometry of construction, dimensions of construction, and nature of construction in terms of method and materials. fire growth is also determined by enclosure of the building with respect of possible ignition sources, uncommon fire risks, ceilings and wall linings, and ventilation circumstances; whether mechanical or materials (Chow 2009, pp. 152-160). It also provides information regarding fuel load in terms of amount of location, amount, type, and arrangement of combustibles. Environmental factors are also considered in relation to ambient movement of air, and temperature conditions. Part 3 Spread of smoke and toxic gases in and beyond enclosure of origin (SS2) London City Hall building was also constructed under the guidance of the BS 7974 building code. The code requires the building is constructed by considering treatment of the movement of smoke and management and control problems. Grimvall, Holmgren and Jacobsson (2010, pp. 225-245) say that he complexity of interaction between fire, building and people is such that there are no single calculation measures that can be used to all kinds of buildings under all situations. Therefore, FSE principles maintain that there should be a high intensity of care and responsibility by designers compared to application of prescriptive codes. It also holds that the FSE measures must be handled by apt qualified and competent personnel so as to reduce the number of mistakes. In the assessment of the suitability of FSE design personnel, professional qualifications like Chartered Membership of the Institute of Fire Engineers (CMIFE), knowledge and skills on the present handbooks and engineering guidance and experience on difficult projects must be considered. Explicitly, as per BS 7974, the earliest design of the building considered smoke systems. Impliedly, smoke control systems are necessary as they provide effective means-of-escape travel distances in the building. Besides, the smoke control systems must be designed to uphold a tenable environment for occupants to facilitate their safe egress from the burning to a secured place. These systems are essential for safeguarding the enclosure of fire origin and prevention of fire from spreading adjacent spaces (Chow 2009, pp. 152-160). Notably, the construction of the London City Hall took into account the design of these smoke control systems so as to maintain safety in case of fire outbreak. Structural response and fire spread beyond the enclosure of origin (SS3) Here, the code of building focuses on the conditions in a fire enclosure and capacity to cause fire spread through recognized routes and mechanisms. It also addresses mechanical and thermal reactions of enclosure limits and its organization to fire conditions. Besides, there it considers the effect of the expected mechanical and thermal reactions on adjoining enclosures and places (Grimvall, Holmgren and Jacobsson 2010, pp. 225-245). In Addition, the code focuses on organizational response of load-bearing substances and their impact on structure stability, acceptable damage and load transfer (Stationery Office 2006 pp. 18-30). It is, therefore, worth noting that the London City Hall’s design and construction were based on these guidelines. Detection of fire and activation of fire protection systems (SS4) BS 7974 also demonstrates the importance of considering the installation of fire detections and activation of fire control systems and alarms in order to maintain fire safety in buildings (Grimvall, Holmgren and Jacobsson 2010, pp. 225-245). Here, the code guides that all buildings should be designed and constructed to minimize the danger of fire. The kind and degree of fire detection systems required are determined by a number of factors that include basic objects of the design. For example, if a fire outbreak is likely to be seen by a person before it affects other people in the building, a manual system can be used. On the other hand, if a building is unmanned, a manual response is inappropriate, but an automatic system or sprinkler system is suitable (Chow 2009, pp. 152-160). The main requirements of the fire detection systems are the capacity to distinguish between fires causing danger and non-fires; react to possible combustion materials that are hazardous in the building; provide signal to activate fire control or warning systems in time; and to be adequately available and dependable to act when needed. Notably, London City Hall is installed with both manual and automatic fire detection systems so as to maintain safety in case of fire. It also has appropriate activation of fire control and alarm system that can alert all occupants in case of emergency. Fire service intervention (SS5) The code also provides guidelines on the fire service intervention, and assesses the rate of build-up of fire service’ fire-fighting resources. This implies the installation of in-house fire fighting devices or enlisting the help private fire brigades. Besides, the code focuses on the time difference between the fire service arrival and the beginning of their fight on the fire, together with time differences in relation to build-up of extra fire service assets and the degree of fire-fighting resources, and extinguishing ability accessible at certain times (Chow 2009, pp. 152-160). Therefore, the code requires that the building is designed in such a way that it allows easy movement and access by fire-fighters. It should also be appropriately externally designed to allow smooth access by vehicles, and have consistent water supplies necessary in fire fighting. Hydrants should be located in paces near the building entry points, and fire service parking positions. Imperatively, the London City Hall construction was done with these requirements in mind. Human factors: Life safety strategies- Occupant evacuation, behavior and condition (SS6) The PD provides guidance to regulators and designers and fire safety personnel on engineering techniques accessible for assessment of life safety features of FSE design regarding evacuation plans. It stresses on designing buildings in a way that will reduce occupants’ exposure to fire. Besides, it ensures that any exposure to fire does not prevent occupants’ safe egress, without any critical health effects. It also guides on the assessment and management of occupants’ behavior, especially egress behavior, during an emergency and for assessment of occupant condition, in specifically regarding exposure to heat and fire effluent (Stationery Office 2006 pp. 18-30). Therefore, many buildings like the London City Hall are constructed with both ASET and RSET considerations in order to facilitate life safety. Conclusion BS 7974 building has been quite influential in the provision of guidelines regarding design and construction of safe buildings in the United Kingdom. With respect to the London City Hall building, it is explicit that the designers and architects considered the code’s requirements regarding fire safety engineering measures. This has, since its construction, ensured safety of occupants in case of fire emergency. The code is supported by six sub-systems that involve the start and growth of fire in the enclosure of origin; the spread of toxic gases and smoke in and beyond the origin enclosure; the structural response and spread of fire in enclosure of origin; fire detection and activation of fire detection systems; fire service intervention; and evacuation. References Babrauskas, V, Fleming, JM & Russell, BD 2010, ‘RSET/ASET, a flawed concept for fire safety assessment’, Fire Mater, vol. 34, no.4, pp, 341–355. Chow, TT 2009, Development trends in building services engineering, City University of Hong Kong Press, Hong Kong. Pp. 152-160. Christian, S 2003, A guide to fire safety engineering, BSI, London. Pp. 4-20 Grimvall, G, Holmgren, A & Jacobsson, P 2010, Risks in technological systems, Springer, London. Pp. 225-245. Stationery Office 2006, Fire safety, TSO, London. Pp. 18-30. Read More