Means of Escape and Evacuation Strategy for the Academic Building - Term Paper Example

FIRE SAFETY FOR THE ACADEMIC BUILDING MEANS OF ESCAPE AND EVACUATION STRATEGY .......................................................................... 20 August 2010 Table of Contents Table of Contents 3 Introduction 4 Summary of the building 4 Means of escape and evacuation strategy 5 Means of escape 5 Escape routes and travel distances 6 Vertical escape routes 6 Refuges 7 Horizontal escape 8 Inner rooms 9 Means of escape from the basement 10 Precaution and fire-protection for the escape routes 11 Evacuation strategy 11 Conclusion 12 Reference list 14 Appendix 1: means of escape calculations 15 Introduction This report is a thorough review of issues related to means of escape of an academic building. It examines the building design to provide critical, analytical, discursive and remedial views of its means of escape such that the proposed solutions satisfy the functional requirements included in the Building Regulations of 2000. It provides an overview of the building before touching on the means of escape and evacuation strategies, and the concluding remarks. Summary of the building The building in consideration is an academic building within the University campus that will be used primarily by students. It will be owned and operated by an independent institution or company. The building will include facilities such as lecture theatres and classrooms, dining facilities including a café, flexible group workspace, science laboratories, IT facilities, and staff offices and facilities. The design of the building is somewhat open plan and is rooted in a large atrium space with balcony access on upper levels. The building will have five floors – basement (level 0), ground floor (level 1), first floor (level 2), second floor (level 3), and third floor (level 4). The level 4 floor (third floor or the upper most occupied floor) will be about 12.5m above level one (ground) floor. The overall dimensions of the building will be roughly 46m by 25m, while the ground floor footprint area will be about 780m2. Several voids rising from level one to level four will link common areas of the academic building. It is also noteworthy that as much as there are neither alterations to the neighbouring building nor linking of the existing fire alarm system the architect plans to maximise the unprotected areas on each elevation. Thus, boundary distances of the academic building elevations will be as follows: North elevation will be 5.5m to the elevation of the existing adjacent History Building, East elevation will be 11.5m to the centre of main road, South elevation will be 17m to the elevation of the existing adjacent Arts Building, and the West elevation will be more than 50m to the site boundary. Means of escape and evacuation strategy Means of escape The means of escape is one of the most important aspects in fire safety strategies. The Building Regulations 2000 (British Standards Institution, 2008) tasks architects and designers of buildings to provide appropriate means of escape such that people can exit buildings in the event of fire to a safe location outside the building. The design of the academic building has several aspects that satisfy this requirement, although there are some areas that need improvements. The Department for Communities and Local Government (2007) has identified two distinct aspects to designing means of escape: escape from within a room, and escape from the rooms to the ultimate egress. The considerations include the number and size of escape routes, vertical and horizontal escape, travel distances, inner rooms and common corridors as well as people with special challenges such as people with disability and old age persons. Escape routes and travel distances The alternative escape routes provided in the academic building are sufficient for the academic building. The Department for Communities and Local Government (2007) has highlighted that the number of escape routes and exit points correlates to the number of occupants in a room or storey and the limits on travel distant to the nearest egress. Given it total footprint area of 780m2 the academic building can accommodate more than 600 people. Therefore, it is expected that the building should have at least three alternative escape routes (British Standards Institution, 2008; Department for Communities and Local Government, 2007). Vertical escape routes The three alternative vertical escape routes linking all the floors (except the basement floor) are sufficient in facilitating safe egress of occupants from the building. It is noteworthy that that the locations of the stairways are more appropriate for the upper wing (in reference to the diagrams) but disadvantages the lower wing. For the lower wing (in reference to the diagrams) the positioning of the stairways limits safe egress. For instance, the travel distant from the rooms on floors of the lower wing to stairway no. 2 is longer than acceptable. The Department for Communities and Local Government (2007) recommends a maximum horizontal travel distant of not more than 18 meters to the exit stairways for such a building. However, given there are a total of three stairways, it would be prudent to consider stairway no. 1 and stairway no. 3 as alternative vertical escape routes for this wing. Therefore, the present horizontal travel distant is appropriate to the two alternative stairways. However, the present arrangement and location of the two stairways have a weakness in that their distant apart is less than 45º. The Department for Communities and Local Government (2007), the British Standards Institution (2008), and CISBE (2003) have asserted that travel distance is a critical aspect in fire safety. The sum of the width of the three stairways is satisfactory as recommended. The Building Regulations 2000 allows at least 1000mm as the minimum width for a building holding more than 600 people. The calculations (shown in appendix 1) reveal that the building can accommodate about 780 people. This allows the determination of the minimum width for each escape route. Therefore, the escape routes should be at least 1242 mm wide. The exit capacity for each stairway in regards to simultaneous evacuation would be approximately 390 people. Therefore, any of the two stairways of the academic building can accommodate the entire population (780 occupants) of the building simultaneously. So even if one stairway is blocked the rest two can adequately support evacuation of the whole building population. Note that the undiscounted capacity for three stairways is about 1170 people (Department for Communities and Local Government, 2007). Refuges Since there is a likelihood of people with disability using the building, refuges for the three stairways should be provided. While the number of people using wheel chairs might dictate a larger refuge, at least a size of 900mm x 1400 mm is recommended for each stairway in the academic building (Department for Communities and Local Government, 2007; CISBE, 2003). The refuge should be positioned such that that it does not impede escape through the stairway. It is also important that an emergency voice communication (EVC) is installed together with the refuge. This would help refuge users to seek assistance to exit the building. Labelling in blue of the refuge area with a phrase such as ‘Refuge – Keep clear’ is important. Horizontal escape The horizontal means of escape for the academic are to a large extent designed in accordance to proper fire safety measures. The Department for Communities and Local Government (2007) recommends maximum travel distance of 9 meters from a point in a room to the entrance. For all the rooms in all floors of the academic building, the travel distance from any point of a room to its doorways is less than 9 meters and therefore acceptable. It is also required that the maximum travel distance for a common corridor to any one exit if there are at least two egress is about 18 meters (CISBE, 2003; Department for Communities and Local Government, 2007). The travel distant along the main corridors for all the floors of the academic building to either of three vertical exits (stairways) satisfies this requirement. Moreover, the rest of the corridors, including the lobbies have travel distance that area acceptable. The common corridors should be fire protected given that it serves a critical role in evacuation, and because they serve more than one group of occupancies. The means of escape of the ground floor are designed in accordance to for fire safety measures. There are several alternative escape routes, with some rooms opening directly to the outside. Other rooms open directly to a horizontal exit route (corridor) with only two inner rooms – the Head of Student Services room, and the Furniture Storage Room. Furthermore, the travel distances through these exit routes to the outside within the recommended limits. However, it is noticeable that there are seats along the exit routes, which would be a major obstruction during escape. Therefore, the seats should be removed from these exit routes to allow adequate space for escape. Inner rooms The risk of inner rooms is well established. Such a room involves escape through another room thereby posing a risk if a fire started in that other room (Department for Communities and Local Government, 2007; CISBE, 2003). There are a number of inner rooms in the academic building that necessitate planning for egress from these rooms. These inner rooms include the following: The Furniture Storage Room, and the Head of Student Service room on ground floor The Language/IT lab 2.02, 2.03and 2.04; and the Open Access IT room on the first floor. The Library Resource Area; the Staff Room and Resource Prep Area; the Secure Exam Store; and the Language/IT lab 3.03 on the second floor. The Cleaner Room; the Individual Study Area; and the Teaching Office 4.24 and 4.23 on the third floor. The water closet on the first floor, second floor and third floor. The recommendations in the Building Regulations 2000 ((Department for Communities and Local Government, 2007) allows the existence of the inner rooms such as the Cleaner Room, the Furniture Storage room, Secure Exam Store and the Water Closet. However, it would be advisable to provide alternative doorways for the other inner rooms mentioned above to enhance the safety of occupants. More to the recommendation for the inner rooms is the travel distance allowed from a point within that inner room to an exit of the access rooms. Thus, according to the Building Regulations 2000 this travel distant should not exceed 9 meters (Department for Communities and Local Government 2006). Moreover, the occupant capacity of these inners rooms should be below 30 people. The acceptability of these inner rooms necessitates the installation of appropriate automatic fire detection and alarm system. Means of escape from the basement Both vertical and horizontal escape routes from the basement are adequate. First, the two vertical access (stairways) to the basement are in accordance with the stipulation by the Department for Communities and Local Government (2007); that is, if stairways from upper floors should extends to the basement, then there should be at least one stairway terminate at the ground level. Stairway no.2 terminates at the ground level. Moreover, the lecture theatre has two horizontal exits at the opposite sides that lead to two different stairways. The arrangements of both the vertical routes and horizontal routes in respect to exiting the lecture theatre would allow occupants to safely move away from a fire at any point. Furthermore, they satisfy the 45º requirement stipulated in the Building Regulations of 2000 (Department for Communities and Local Government, 2007). It is also noteworthy that the total widths of the escape routes are sufficient to allow proper evacuation. Precaution and fire-protection for the escape routes It is important that the stairways are adequately fire-protected so that they can provide relative safety during evacuation. The provision of enclosures to the stairways no. 2 and no.3 in the academic building is positive; however, enclosures should be of fire-resisting constructions. It is also proper that the two stairways open to the outside as opposed to the ground floor. It is apparent that there are no enclosures of the stairway number 1. A fire-resisting enclosure should be constructed for this stairway to enhance safety during fire evacuation. The protection of the stairways as well as the common corridors and lobbies should be protected such that air circulation does not allow fire or smoke to spread into these areas. Things such as electricity meters and gas pipes should be avoided within the protected stairways. However, the escape routes should be adequately lit and the lighting system supported by a back up power supply other than the mains. The headroom of the escape routes, except in doorways, should be at least 2 meters. Escape routes should be labelled with clear, visible and unambiguous signs. Door should open in the direction of escape, while door fastening should not be difficult to unfasten. Vision panels should also be provided in places where doors subdivide the escape corridors and lobbies. Evacuation strategy The main aim for an evacuation strategy is to allow occupants of a building where fire has broke out to get to a place outside the building that has ultimate safety (British Standards Institution, 2008). Whereas simultaneous evacuation would be the most appropriate procedure for evacuating people from the academic building in the event of fire, some circumstances may necessitate adoption of a phased evacuation. Thus, phased evacuation procedure would be executed where occupants of a particular area are at immediate risk than other occupants due to, for instance, fire outbreak in or smoke spread into that area. However, in generally, the nature of building and occupants provide for simultaneous evacuation. For instance, the open nature (open plan) of the building construction, and the existence of an atrium would contribute to smoke spread into several rooms and it would be unlikely that occupants would remain in those rooms or floors for an extended time (British Standards Institution, 2008). Therefore, the psychological reactions of the occupants to a fire threat necessitates that a simultaneous evacuation strategy be used in the academic building. In this regard, a two-staged evacuation should be used such that there is first, an investigation by the fire safety staffs before the activation and sounding of the fire alarms. Also, given the building is relatively small, simultaneous evacuation is the most appropriate. Conclusion This report has explored the issues associated with the means of escape of the academic building. It has provided critical analysis on the building design to see if it is in accordance with the guidelines for providing means of escape that allow safe evacuation in the event of fire. Thus, the design has several aspects that are within the stipulations of the Building Regulation 2000, while it is weak in some aspects such as existence of several inner rooms, lack of enclosures for some stairways, and lack of refuges. However, the proposed solutions should improve the means of escape for safe evacuation. Reference list British Standards Institution, 2008. British Standards: Code of practice for fire safety in the design, management and use of buildings - BS 9999: 2008. London: Standards Institution. CISBE, 2003. CISBE guide E: fire engineering. Dorchester, United Kingdom: The Dorset Press. Department for Communities and Local Government, 2007. The building regulations 2000: fire safety approved document B volume 2 - buildings other than dwelling houses. United Kingdom: National Building Specification. Appendix 1: means of escape calculations The number of occupant in the building (No) (Department for Communities and Local Government 2007): The floor area factor for the academic building is about 1.0m2 per person Footprint area = 780m2 Therefore, No = 780 m2 / 1 m2 = approximately 780 people The width and capacity of stairs (for simultaneous evacuation) (Department for Communities and Local Government 2007): p = 200w + 50 (w – 0.3) (n-1) w = (P + 15n- 15) / (150 + 50n) Where: P is the number of people that can be accommodated in the stairs, W is the width of stair in metres, and n is the number of storeys. Thus, P = 780 / 2 = 390, while n = 4 w = 780 + [(15 * 4) - 15] / 150 + (50 *4 ) (390+ 60 -15) / (150 + 200) 435 / 350 w = 1242 mm The total undiscounted capacity for the three stairways is given as below (Department for Communities and Local Government 2007): 390 * 3 = 1170 people Read More