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IS : 1644 - 1888

I ndian StandardCODE OF PRACTICE FOR.FIRE SAFETY OF BUILDINGS ( GENERAL ):EXIT REQUIREMENTS ANDPERSONAL HAZARD

( F irst Revision )~-First Reprint JANUARY lW6

UDC 699.81 : 692622 I-I

@ Copyrrgh I988

BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002or5 h?cmher I968

( Reaffirmed 1998 )

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IS : 1644 1988I ndian St andard

CODE OF PRACTICEFIRE SAFETY OF BUILDINGS FOR( GENERAL ):EXIT REQUIREMENTS ANDPERSONAL HAZARD( Fi rst Rev i si on0. FOREWORD

0.1 This Indian Standard ( First Revision ) wasadopted by the Bureau of Indian Standards on16 May 1988, after the draft finalized by the FireSafety Sectional Committee had been. approvedby the Civil Engineering Division Council.0.2 Indian Standards relating to fire safety ofbuildings have been formulated covering generalprinciples and fire grading, details of construction,exposure hazard and exit requirements. Thisstandard covering the last aspect was formulatedin 1960. In the past 25 years, useful data hasbeen made available by the research institutesof this country as well as from other advancedcountries like USA, UK, Canada, etc. The pro-vision in this revision has, therefore, been madebased on the data adopted by these countries,and therefore, have been completed modified.0.3 The exit requirements and personal hazarddealt with in this standard is considered as atleast of equal importance to all other aspects;in fact in most cases, it is paramount because ofthe density of population associated with parti-cular occupancy; an example is that of a cinemaor similar densely occupied building when con-trasted with a godown of similar occupancy.0.4 Density of population varies from onebuilding to another and also in the same buildingfrom, time to time; one example is that of alarge general or mixed bazar, emporium or storeswhere a great variety of goods are displayed forsale; and at certain periods may be offered atspecial attractive bargain prices, with the resultthat normal population will be rapidly exceeded,more so during peak shopping hours when an

outbreak of fire would cause considerable con-fusio?, poss_ibly panic; therefore, the closetattention to design and maintenance of escaperoutes including any staircases, cannot be over-emphasized. Likewise special consideration. isessential to arrangement of display of any highlyflammable articles or materials for sale in suchrisks because of the danger normal escape routesbeing made unsafe or altogether useless.0.5 It would be neither possible nor advisable torely on electrical or mechanical devices, such aslifts for moving the population of various floorsto a place of safety because of the probability offire rendering these devices inoperative. There-fore, staircases with associated escape routesbecome all important and staircases consideredin this code are the means of communication inan up and down direction of a building and servenot only as escape routes for occupants but alsoafford a direct means of access to the source offire by the fire fighting -staff. In fact, staircaselandings of buildings which present a serioushazard are required to have fire fighting equip-ment mounted thereon comprising hydrant stand,pipes and accessories.0.6 For the purpose of d!ciding whether a parti-cular requirement of this standard is compliedwith, the final value, observed or calculated,expressing the result of a lest or analysis, shall berounded off in accordance with IS : 2-1960*.The number of significant places retained in therounded off value should be the same as that ofthe specified value in this standard.

*Rules for rounding off numerical values ( revised ).

1. SCOPE a building when on fire is vital and all routes1.1 This standard covers requirements regarding should be ,constructed to ensure that the popu-fire safety Of buildings with respect t0 exit require- lation reaches a place of safety in the shortest ments and personal hazard. period of time without undue hindrance bysmoke, fumes, debris and the like.2. EXIT REQUIREMENTS Every building meant for human occupancy2.1. Ample provision for escape of population of should be provided with exits sul%cient to permit

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IS : 1644 - 1988safe escape of occupants, in case of fire or otheremergency.2.2 Types of Exits

2.2.1 An exit may be a doorway, a corridor orpnssagewny(s) to an internal staircase, orexternal staircusc, or to a verandah or terr:&s)which have ~CCCSSo the street, or roof Of abuilding, or ;I rcfugc are& An exit may alsoinclude a horizontal exit leading to an adjoiningbuilding at the same level.

2.2.2 Lifts and escalators should not be con-sidered as exits.2.3 General

2.3.1 In every building, exits should complywith the minimum requircmwts except those notaccessible for general public USC.2.3.2 All exits should be free of obstructions.2.3.3 No building should SO altered as toreduce the number, width or protection of exits

to less than that required.2.3.4 Exits should be clearly visible and the

routes to reach the exit should be clearly markedand sign posted to guide the population of thefloor concerned. Signs should be painted withilluminated paint.NOTE -This provision shou1.d not apply to A-2 and2;45;ccupancies up to 15 m In height ( sec2.7.3 and. . .

2.3.5 Where necessary, adequate and reliableillumination should be provided for exits.2.3.6 Fire check doors 1 WC IS : 3614 ( Part1 )-1966* 1 should at appropriate places alongthe escape routes to prevent spread of fire andsmoke and particularly at the entrance to liftsand stairs where a funnel or flue effect may becreated, including an upward spread of fire.2.3.7 All exits should provide continuousmeans of access to the exterior of a building orto an exterior open space leading to a street,2.3.8 Exits should be so arranged that they

may be reached without passing through anotheroccupied unit.2.4 Occupant Load - For determining the exitsrequirement, the number of persons within anyfloor area or the occupant load should be basedon the actual number of occupants, but in nocase less than that specified in Table 1.

2.4.1 hfcza/liuc and Bdcotl~~ - The occupantload of a mezzanine floor and balcony discharg-ing to a floor below should be added to that flooroccupancy load thus established.*Specification for fire-check doors: Part I plate, nletalcoxred and rolling ry~c.

Cl.101.2.3.4.

5.

6.7.8.

TABLE 1 OCCUPANT LOAD( Clause 2.4 )

GlrolJl OF OCcliP.\NCY Ot~c~uraw LOAD, FLOOR( see IS : 1641-1988; ) ARE_\ IN m/PEltSoxResidential (A) 12.5Educational (B) 4Institutional (C) 1stAssembly: (D)a) With fixed or loose seatsand dance floors 06.tb) Without seating facilitiesincluding dining rooms 15$Mercantile: (F)a) street floor and salesbasement 3b) upper salt floorsBusiness and industrial I E and G ) 10Storage (H) 30Hazardous (J) 10*Code of practice for the safety of buildings (general ):General principles of fire grading and classifications

( jrst revision ).- _ _*Occupant load in dormitory portions of homesfor the aged, orphanages, insane asylums etc, wheresleeping accommodation is provided, should be cal-culated at not less than 7.5 m* gross floor area/person.fThe gross floor area should include, in additionto the main assembly room or space, any occupiedconnecting room or space in the same storey or inthe storeys above or below where entrance is commonto such rooms and spaces and they are available foruse by the occupants of the assembly place, Nodeductions should be made in the gross area forcorridors, closets or other subdivisions; the area should

include all space serving the particular assemblyoccupancy.2.5 Capacity of Exits

2.5.1 The unit of exit width, used to measurethe capacity of any exit, should be 50 cm. A clearwidth of 25 cm should be counted as an addi-tional half unit. Clear widths less than 25 cmshould not be counted for exit width.2.5.2 Occupants per unit exit width should bein accordance with Table 2.2.5.3 Horizontal Esit Allo~~~orzcc When hori-zontal exit is provided in buildings of mercantile,storage, industrial, business and assembly OCCU-panties, the capacity per store) per unit width ofexit of stairways in Table 2 m:~y be increased by50 percent; and in buildings of institutionaloccupancy, it may be increased by 100 percent.

2.6 Arrangement of Exits2.6.1 Exits should be so located that the traveldistance on floor should not exceed the distancegiven in Table 3.2.6.2 The travel distance to an exit from the

dead end of a corridor should not exceed half thedistance specilicd in Table 3. CSCL~In cdncational,

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TABLE 2 OCCUPANTS PER UNIT EXIT WIDTHSLNo.

(1)1.2.3.4.5.6.7.8.9.

( Clauses 2.5.2 and 2.5.3 )GROUP OF NUMBEROF

&CUP ANCY OCCUPANTS( See IS : 1641-1988* )r-----h----~Stairways Ramps Doors

(2) (3) (4) (5)Residential ( A ) 25 50 75Educational ( B ) 25 50 75Institutional ( C ) 25 50 75Assembly (D ) 40 50 60Business (E) 50 60 75Mercantile ( F) 50 60 75Industrial ( G ) 50 60 75Storage (H) 50 60 75Hazardous ( J ) 25 30 40

*Code of practice for safety of buildings ( general ):General principles of fire grading and classification (firstrevision ).assemby and institutional occupancies in whichcase it should not exceed 6 m.

2.6.3 Whenever more than one exit is requiredfor any room, space or floor of a building, exitsshould be placed ps remote from each other aspossible and should be arranged to provide directaccess in separate directions from any point inthe area served.TABLE 3 TRAVEL DISTANCE FOR OCCUPANCYAND TYPE OF CONSTRUCTION

SLNo.

(1)1.2.3.4.5.6.7.8.9.

( Clauses 2.6.1 and 2.6.2 )G tOIP OF M~YIMU~IRAVEL0s (liP.\N(Y Drsrr !\N(ECONSTRUCTION( see IS : 1641-1988* ( see IS : 1642-1988)r----- h ----_yType 1 and 2 Type 3 and 4(2) (3) (4)m mResidential ( A ) 22 5 22.5Educational ( B ) 22.5 22.5Institutional ( C ) 22.5 22.5Assembly (D) 30.0 300Business (E) 30.0 30.0Mercantile ( F ) 30.0 30.0Industrial (G) 450 30.0Storage (H) 30 0 300Hazardous ( J ) 225 22.5

*Code of practice for fire safety of builders( general ): General principles of fire grading and classili-cation (first revision ).tCode of practice for fire safety of buildings( general ): Details of construction (first revision),

2.7 Number of Exists2.7.1 Gencrul Rcquircmcnt -All buildings whichare more than 15 m in height and all buildingsused as educational ( B ), assembly ( D 1, insti-

tutional ( F ), industrial ( G 1, Storage ( H ), andhazardous ( J ) occupancies and mixed occupancieswith any of the aforesaid occupancies, havingarea more than 500 mZ on each floor should havea minimum two staircases. They should be of

IS: 1644.l!a8enclosed type; at least one of them should be .onexternal walls of buildings and should opendirectly to the exterior, interior open space or toan open place of safety. Further, the provisionor otherwise of alternative staircase should besubject to the requirements of travel distancebeing complied with.

2.7.2 Rooming Houses of Residential Buildings( A-I ) - Every sleeping room above the streetfloor should have access to two separate meansof exit, at least one of which should consist of anenclosed interior stairway or an exterior stairway,or a fire escape or horizontal exit, all so arrangedas to provide a safe path of travel to the outsideof the building without traversing any corridoror space exposed to an unprotected verticalopening. Any sleeping room below the streetfloor should have direct access to the outside ofthe building.2.7.3 One or Two Family Private Dwellings orResidential Building ( A-2 )

2.7.3.1 For more than two rooms, everyoccupied room excluding areas used solely forstorage, should have at least two means of exit,at least one of which should be a door or astairway providing a means of unobstructedtravel to the outside of the building or street orgrade level and not more than one of which maybe a window. No room or space should beoccupied which is accessible only be a ladder,folding stairs or through a trap door.

2.7.3.2 All locking devices which wouldimpede or prohibit exit, such as chain type bolts,limited opening sliding type locks and burglarlocks which are not disengaged easily by quick-releasing catches, should be prohibited. All closetdoor latches should be such that even childrenmay open the doors from inside. All bathroomdoor locks or fasteners should be designed to per-mit the opening of the locked or closed dooifrom the outside in an emergency without the useof a special key. Every below-street-level sleepingroom should have direct access to the outside ofthe building.

2.7.4 Dormitories ( A-3 ) - All dormitories,except those mentioned in 2.7.6 should have exitsso arranged that from any sleeping room or opendormitory sleeping area, there should be access totwo separate and distinct exits in differentdirections with no common path of travel unlessthe room or space is subject to occupancy by notmore than 10 persons and has a door openingdirectly to the outside of the building at street orgrade level, or to an outside stairway in whichcase one means of exit may be accepted.

2.7.5 Apartment House ( A-4 )2:7&l Every individual living unit shouldcomply with the requirements for occupancy sub-division A-2 in respect of exit ( see 2.7.3 ) ,

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IS : 1644 19882.7.5.2 Every living unit should have accessto at least two separate exits which are remotefrom each other and are reached by travel indifferent directions except that a common path oftravel may be permitted for the first 6 m (that is,a dead-end corridor up to 6 m long may be per-mitted ) provided that single exit may be

permitted under any of the conditions givenin 2.7.5.3.2.7.5.3 Any building not more than twostoreys in height with no basement, or in casethere is a basement and with street floor level notmore than 25 m above ground at any point nextto the building, excluding driveways, not morethan 10 percent of the perimeter should be sub-ject to the condition that the access to the base-ment is only from the exterior of the building ifthe basement contains a heating plant, groupstorage, incinerator room or paint shop or otherhazardous occupancy.2.7.5.4 At least half of required exits shoulddischarge direct to the outside of the buildings;any other exit should be the same as required forthe hotels ( see 2.7.6 ).

2.7.6 Hotels ( A-5 )2.7.6.1 Not less than two exits, as remotefrom each other-as practicable, should be acces-sible from every floor, including basementsoccupied for hotel purposes, except as a singleexit as permitted in 2.7.6.2 below. Exits and waysof access thereto should be so arranged that theyare accessible in at least two different directionsfrom every point in any open area, or from anyroom door.2.7.6.2 Any room or section with an outsidedoor at street or grade level may have such out-side door as a single exit provided no part of theroom or area is more than 15 m from the dourmeasured along the natural path of travel.2.7.6.3 Where stairways or other exits servet\iro or more upper floors, the same stairway orother exit required to serve any one upper floormay also serve other upper floors except that noinside open stair-way or ramp may serve as arequired egress facility from more than onefloor.

NOTE - Under this provision, if the second and thirdfloors wereeach required to have three stairways, thesecond floor may use the stairways serving the thirdfloor so that tho total number of stairways requiredis three, and not six.2.7.7 Basement Exits for Residential Buildings

should there be less than two independent base-ment exits.2.7.7.3 Basements or sub-basements not opento the public and used only for heating equipment, storage and service operations ( other thankitchens which are considered part of the hoteloccupancy ) should have exits appropriate to theactual occupancy, in accordance with applicableprovisions or in case of mixed occupancy wherethere may be doubt as to which other section isapplicable, such basements should have exitsdetermined on the basis of lesser exit capacity.

2.7.8 Educational ( B )2.7.8.1 At least two separate exits are availa-ble. in every floor area. Exits should be asremote from each other as practicable and soarranged that there are no pockets or dead endsof appreciable size in which occupants may be

trapped.2.7.8.2 Every room with a capacity of over100 persons in area should have at least two door-ways as remote from each other as practicable.Such doorways should provide access to separateexits but may open upon a common corridorleading to separate exits in opposite directions.2.7.8.3 Exterior doors should be operated bybars or some other panic hardware device exceptthat doors leading from classroom directly to theoutside may be equipped with the same type oflock as is used on classroom doors leading to

corridor with no provision whatsoever for lock-ing against egress from the classroom.2.7.9 Institutional ( C )

2.7.9.1 In buildings or sections occupied bybedridden patients where the fl bar area is over 280m2, f.uzillties should b;: provided to move patientsin hospital beds to the other side of a smokebarrier from any part of such building or sectionnot directly served by approved horizontal exitsor exits from the first floor ( Floor 2 ) of abuilding to the outside.2.7.9.2 Not less than two exits of one or moreof t!le following types should be provided forevery floor, including basement, of every buildingor section:

a) Doors leading directly outside the building,bj Stairways,c) Ramps, andd) Horizontal exits.(A)

2.7.7.1 Basements occupied for hotel pur- 2.7.9.3 All required exits which serve asposes should have exits arranged in accordance egress from hospitiil or infirmnry sections shouldwith 2.7.6 be not less than 150 cm in clear width, includiingpatient bedroom doors, to permit transportat on2.7.7.2 Basement exits should be sufficient to of patients on beds, litters or mattresses. .Theprovide for the capacity of the basement as deter- minimum widths of corridors serving patientsmined in accordance with 2.3 and in no case bedrooms in building should be 240 cm.

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IS:1644- 19882.7.9.4 Revolving doors should not becounted as required exits and should not be ins-talled, except in situations, such as revolving doorsat a main entrance where they are not subject toemergency exit use by patients.2.7.9.5 Elevators constitute a dcsirablc supp-lementary facility but are not counted as requiredexits.2.7.9.6 Each storey in which 35 or morepatients are housed should be divided into atleast two compartments by smoke barriers and theAuthority may require storeys housing a lessernumber of patients to be divided into compart-ments when, in its judgement, such division isessential for the protection of the patients.2.7.9.7 Doors in smoke barriers should be soinstalled that these may normally be kept in openposition but will close automatically or may bereleased manually to self-closing action. Corridordoor openings in smoke barriers should not beless than 150 cm in width. Provision should alsobe made for double swing single/double leaf typedoor.2.7.9.8 Exits and other features for penal andmental institutions, and custodial institutionsshould be the same as specified for hospitals, inso far as applicable. Reliable means should beprovided to permit the prompt release of inmatesfrom any locked section in case of fire or otheremergency.2.7.9.9 Wherever any inmates are confined inany locked rooms or spaces, adequate guards orother personnel should be continuously on dutyor immediately available to provide for releaseof inmates or for such other action as may beindicated in case of fire or other emergency.2.7.9.10 No building constructed in wholeor in part of combustible materials should beused to combine inmates in cells or sleepingquarters unless automatic sprinkler protection isDrovided.

exits remote from each other as practicable andif of capacity over 600, at three exits should beprovided with each exit not less than of 2 u. itwidths.2.7.10.4 Every place of assembly of sub-

divisions D-3, D-4 and D-5 should have at Ieasttwo means of exit, consisting of separate exitsor doors leading to corridor or other spacesgiving access to- two separate and independentexits in different directions, except that for placesof assembly having a capacity of less than 100persons, one 2-unit doorway may be permitted inrooms where no part of the room is more than15 m from the doorway, measured along the lineof travel, and the doorway leads directly outsidethe building at grade level or leads to a corridoror other space giving access to two separate andindependent exits.2.7.10.5 Clear aisles not less than 12 m inwidth should be formed at right angles to theline of seating in such number and manner thatno seat should be more than seven seats awayfrom an aisle. Rows of seats opening on to anaisle at one end only should have not more thanseven seats. Under the conditions where all theseaisles do not directly meet the exit doors, cross-aisles should be provided parallel to the line ofseating so as to provide direct access to the exit, .provided that not more than one cross-aisle forevery 10 rows should be required. The widthof cross aisles should be a minimum of 1 m. Steps

should not be placed in aisles to overcomedifferences in levels unless the gradient exceeds1 in 10.2.7.10.6 The fascia of boxes, balconies andgalleries should have substantial railings not lessthan 65 cm high above the floor. The railingsat the end aisles extending to the fascial shouldbe not less than 75 cm high !i)r the width of theaisle or 90 cm high at the foot of steps.2.7.10.7 Cross-aisles except where the backsof seats on the front of the aisle project 60 cm or

2.7.9.11 All buildings or sections of build more above the floor of the aisle, should be pro-ings penal and mental institutions used for manu- vided with railings not less than 90 cm high.facturing, storage or office purposes should have 2.7.10.8 No turnstiles or other devices toexits in accordance with the provisions of occu- restrict the movement of persons should bepanties. installed in any place of assembly in such a

2.7.10 A.vwmb/y Building ( D ) manner as to -interfere in any way with therequired exit facilities.2.7.10.1 Every place of assembly, every tieror balcony, and every individual room used as aplace of ashembly should have exits sufficient toprovide for the total capacity thereof as deter-mined in accordance with 2.7.7.2.7.10.2 Every place of assembly of sub-

division D-i should have at least four separateexits as remote from each other as practicable.2.7.10.3 Every place of assembly of sub-division D-2 should have at least two separate

2.7.10.9 In theatres and similar places ofpublic assembly where persons are admittedto the building at a time when seats are notavailable for them and are allowed to wait in alobby or similar spsce until seats are available,such use of lobby or similar space should not en-croach upon the required clear width of exits.Such waiting should be restricted to areas sepa-rated from the required exitways by substantialpermanent partitions or fixed rigid railing notless than I05 cm high. Exits should be provided5

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IS .: 1644 988for such waiting spaces on the basis of one personfor each 03 mt of waiting space area. Suchexits should be in addition to the exits specifiedfor the main auditorium area and should conformin construction and arrangement to the generalrules of exits given above.

2.7.10.10 No display or exhibit should beso installed or operated as to interfere in anyway with access to any required exit, or with anyrequired exit sign. All displays or exhibits ofcombustible material or construction and allbooths and temporary construction in connectionwith it should be so limited in combustibility orprotected as to avoid any undue hazard of firewhich might endanger occupants before they haveopportunity to use the available exits.2.7.10.11 No mirrors should be placed in oradjacent to any exitway in such a manner as toconfuse the direction of the exit.27.10.12 Places of assembly in buildings of

other occupancy may use exits common to theplace of assembly and other occupancy. Providedthe assembly area and other occupancy are consi-dered separately, each has exits sufficient to meetthe requirements.2.7.10.13 Exits should be sufficient for simul-taneous occupancy of both the places of assemblyand other parts of the-building, unless the con-ditions are such that simultaneous occupancywill not occur.

2.7.10.14 For any place of assembly undersubdivision D-l, at least half the required meansof exits should lead directly outdoors or throughexitways completely separated from exits servingother parts of the building.

2.7.11 Business ( E )2.7.11.1 In the caseof mezzanines or balco-nies open to the floor below, or other unprotectedvertical openings between floors, the populationof the mazzanine or other subsidiary floor levelshould be added to that of the main floor for thepurpose of determining the required exits, pro-vided, however, that in no case should the totalnumber of exits, units be less than that requiredif all the vertical openings were enclosed.2.7.11.2 Not less than two exits should beprovided for every floor, including basementsoccupied for office purposes or uses incidentalthereto.

2.7.12 Mercantile ( F )2.7.12.1 In the case of mezzanines or bal-conies open to the floor below, or other un-protected vertical openings between floors, thepopulation or area of the mezzanine or othersubsidiary floor level should be added to that ofthe main floor for the purpose of determiningthe required exits, provided, however, that in nocase should the total number of exits units be less

than that required if ail vertical openings wereenclosed.2.7.12.2 At least two separate exits shouldbe accessible from every part of every floor,including basements; such exits should be asremote from each other as practicable and soarranged as to be reached by different paths oftravel in different directions except that acommon path of travel may be permitted for thefirst 15 m from any point.

2.7.13 I ndustrial ( G )2.7.13.1 Not less than two exits should beprovided for every floor or section, includingbasements used for industrial purposes or usesincidental thereto.2.7.13.2 In buildings used for aircraftassembly or other occupancy requiring undividedfloor areas so large that the distance from pointswithin the area to the nearest outside walls

where exit doors could be provided are in excessof 45 m, requirements for distance to exits maybe satisfied by providing stairs leading to exittunnels or to overhead passageways. In caseswhere such arrangements are not practicable,permit other exit arrangements for one storeybuildings with distance in excess of the maximumdistances specified in 2.6. If completely auto-matic sprinkler protection is provided and if theheights of ceiling curtain boards and roof venti-lation are such as to minimize the possibilitythat employees will be overtaken by the spreadof fire or smoke within 180 cm of the floor levelbefore they have time to reach exits, provided,however, that in no case may the distance oftravel to reach the nearest exit exceed 120 mwhere smoke venting is required as a conditionfor permitting distances of travel to exits in excessof the maximum otherwise allowed.

2.7.13.3 Basements used only for storage,heating and other service equipment, and notsubject to industrial occupancy should have exitsin accordance with the requirements of Group Hoccupancies.2.7.13.4 The following exceptions shouldapply to special purpose industrial occupancies:

b)

Exits need be providod only for theppersons actually employed; spaces notsubject to human occupancy because ofthe presence of machinery or equipmentmay be excluded from consideration.Where unprotected vertical openings arenecessary to manufacturing operations,these may be permitted beyond the limitsspecified for industrial occupancy pro-vided every floor level has direct access toone or more enclosed stairways or otherexits protected against obstruction by anyfire in the open areas connected by the

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unprotected vertical openings or smoketherefrom.2.7.13.5 The following exceptions shouldapply to high hazard industrial occupancies:

a) Exits should be so located that it will notbe necessary to travel more than 225 mfrom any point to reach the nearest exit.b) From every point in every floor area,there should at least be two exits acces-sible in different directions; where floorareas are divided into rooms, there shouldbe at least two ways of escape from everyroom, however small, except toilet rooms,so located that the points of access theretoare out of or suitably shielded from areasof high hazard.c) In addition to types of exits for upper

floors specified for Group G occupancies,slide escapes may be used as requiredexits for both new and existing buildings.2.7.14 Stora ge ( H )

2.7.14.1 Every building or structure used forstorage, and every section thereof consideredseparately, should have access to at least oneexit so arranged and located as to provide asuitable means of escape for any person employedtherein and in any room or space exceeding 1 400m2 gross area, or where more than 10 persons maybe normally present, at least two separate meansof exit shall be available, as remote from eachother as practicable.2.7.14.2 Every storage area should haveaccess to at least one means of exit which can bereadily opened. This should not be subject tolocking so long as any persons are inside andshould not depend on power operation.2.7.14.3 The following special provisionsshould apply to parking garages of closed oropen type, above or below ground but notto mechanical parking facilities where auto-mobiles move into and out of storage mechani-cally which are not normally occupied by personsand thus require no exit facilities. Where repairoperations are conducted, the exits shouldcomply with the requirements of Group Goccupancies in addition to compliance with thefollowing:

a)

b)

Where both parking and repair operationsareconducted in the same building, theentire building should comply with therequirements for Group G occupanciesunless the parking and repair sections areeffectively separated by separation walls.Every floor of every closed parking garageshould have access to at least two separatemeans of exit so arrnngcd that from anypoint in the garage, the paths of travel to

cl

d)

e)

f )

d

IS : 1644 - 1988the two means of exit should be in differentdirections, except that a common path oftravel may be permitted for the first 15 mfrom any point.On the street floor, at least two separateexit doors should be provided except thatany opening for the passage of automobilesmtiy serve as a means of exit provided nodoor or shutter is installed thereon. Streetfloor exits in closed garages should be soarranged that no point in the area is morethan 30 m from the nearest exit, or 45 min the case of garages protected by auto-matic sprinklers, distance being measuredalong the natural path of travel.On floors above the street, at least twomeans of exit should be provided, one ofwhich should be an enclosed stairway.The other means of egress may be asecond exit of any of the types, or in aramp type garage with open ramps notsubject to closure, the ramp may serve asthe second means of exit.Upper floor exits in closed garages shouldbe so arranged that no point in the areashould be more than 30 m from thenearest exit other than a ramp on the samefloor level, or 45 m in the case of garagesprotected by automatic sprinklers.On floors below the street ( either base-ment or outside underground garages ),at least two exits should be provided, notcounting any automobile ramps exceptthat for garages extending only one floorlevel below the street, a ramp leadingdirect to the outside may constitute onerequired means of exit. In garagesbelow street level, exits should be soarranged that no part of the area shouldbe more than 30 m from the nearest stairexit.If any gasoline pumps are located withinany closed parking garage, exits should beso located that travel away from the gaso-line pump in any direction should lead to anexit, with no dead-end in which the occu-pants might be trapped by fire or explosionat any gasoline pump. Such exit should leadto the outside of the building on the samelevel, or downstairs; no upward travelshould be permitted unless direct outsideexits are available from the floor and anyfloor below ( as in the case of a basementgarage where the grade is one storey ormore lower at the rear than at the street ).

2.7.14.4 Exits from aircraft hangars ( storageor servicing areas ) should be provided at inter-vals of not more than 45 m on all exterior wallsof aircrafts hangars. There should be a minimumof two exits serving each aircraft storage or

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IS:1644-1988servicing area. Horizontal exits through inte-rior fire walls should be provided at intervals ofnot more than 30 m. Dwarf or smash doorsin doors accommodating aircraft may be used tocomply with these requirements. All doorsdesignated as exits should be kept unlocked inthe direction of exit travel while the area isoccupied.

2.7.14.5 Exits from mezzanine floors in air-craft storage or servicing area should be so arran-ged that the maximum travel to reach the nearestexit from any point on the mezzanine should notexceed 225 m. Such exits should lead directlyto a properly enclosed stairwell dischargingdirectly to the exterior or to a suitably cut-offarea or to outside fire escape stairs.2.7.14.6 The following provisions shouldapply to grain elevators:

a)

b)

cl

4

There should at least be one stair towerfrom basement to first floor and from firstfloor to top floor of the workhouseenclosed in a dust-tight non-combustibleshaft;Non-combustible doors of self-closingtype should be provided at each floorlanding;An exterior fire escape of the stair orbasket ladder type should be providedfrom the roof of the workhouse to theground level or to the roof of an adjoiningannexe with access from all floors abovethe first; andAn exterior fire escape of either the stairor basket ladder type should be providedfrom the roof of each storage annexe tothe ground level.

2.7.14.7 Every area used for storage ofhazardous commodities should have an exitwithin 225 m of any point in the area wherepersons may be present or 30 m where automaticsprinkler protection is provided.2.7.15 Hazardous ( J) - Same as in 2.7.13.5.

2.8 Doorways2.8.1 Every exit doorway should open intoan enclosed stairway, or horizontal exit of acorridor, or passageway providing continuousand protected means of egress.28.2 No exit doorway should be less than 100cm in width. Doorways should be not less than200 cm in height.2.8.3 Exit doorways should open outwards,that is, away from the room but should notobstruct the travel along any exit. No door,when opened, should reduce the required widthof stairway or landing to less than 90 cm; over-head or sliding door should not be installed.

NOTE-In the case of buildings where there is acentral corridor, the doors of rooms should openinwards to permit smooth flow of traffic in thecorridor.2.8.4 Exit door should not open immediatelyupon a flight of stairs, a landing equal to at leastthe width of the door should be provided in thestairway at each doorway; the level of landingshould be the same as that of the floor whichit serves.2.8.5 Exit doorways should be openable fromthe side which they serve without the use of akey.2.8.6 Revolving Doors

2.8.6.1 Revolving doors should not be usedas required exits except in residential, businessand mercantile occupancies but should not cons-titute more than half the total required doorwidth. In mercantile buildings where there ispossibility of congregation of a large number ofpeople ( more than 200 ), revolving doors shouldnot be permitted.

2.8.6.2 Where the revolving door providedare completely made of glass ( plate glass l, a redcircle or emblem or logo at 15 m level above sillshould be painted on the glass. The thicknessof the glass should not be not less than 12 mm.2.9 Corridors and Passageways

2.9.1 Exit corridors and passageways shouldbe of width not less than the aggregate requiredwidth of exit doorways leading from them in thedirection of travel to the exterior.2.9.2 Where stairways discharge through corri-dors and passageways, the height of corridorsand passageways should be not less than 24 m.

2.10 Internal Staircases2.10.1 Interior stairs should be constructed ofnon-combustible materials throughout.2.10.2 Interior staircase should be constructedas a self-contained unit with an external wallconstituting at least one of its sides and shouldbe completely enclosed.2.10.3 A staircase should not be arrangedround a lift shaft unless the latter is totallyenclosed by a material of fire-resistance rating asthat for the type of construction itself.2.10.4 Hollow combustible construction shouldnot be permitted.2.10.5 No gas piping should be laid in the

stairway.2.10.6 Notwithstanding the detailed provisionfor exits given above the following minimumwidth should be provided for staircases:8

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a) Residential .buildiilgs ( dwellings ) 10 mNom - For row housing with 2 storeys, the widthshould lx 075 m.

b)44

4

f)

Residential hotel buildings 15mAssembly buildings like auditorium, 15 mtheatres and cinemasEducational buildings:

i) Up to 24 m in height 15 mii) More than 24 m in height 20 mInstitutional buildings like hospitals:i) Up to 10 beds I.5 m

ii) More than 10 beds 20 mAll other buildings 15 m

2.10.7 The minimum width of tread withoutnosing should be 25 cm for internal staircase ofresidential buildings. This should be 30 cm forassembly, educational, institutional, business andother buildings. The treads should be constructedand maintained in a manner to prevent slipping.

2.10.8 The maximum height of riser should beI9 cm for residential buildings and 15 cm forother buildings and the number should be limitedto 15 per flight.210.9 Hand rails should be provided at aminimum height of 100 cm and not exceeding 120cm to be measured from the basesf the middle ofthe treads to the top of the hand rails. Further,

the gap between the two verticals should notexceed 30 cm. This gap should be reduced to 15cm where children are likely to use the staircase.2.10.10 The number of people in between floorlandings in staircase should not be less than thepopulation on each floor for the purpose ofdesign of staifcase.

2.11 Fire Escapes or External Stairs2.11.1 Fire escapes should not be taken intoacco-lnt in calculating the evacuation time of abuild ng.2.11.2 All fire escapes should be directlyconnected to the ground.2.11.3 Entrance to the fire escape should beseparate and remote from the internal staircase.2.11.4 Care should be taken to ensure that thewall opening or window opens on to or close to afire escape.2.11.5 The route to the fire escape should befree of obstructions at all times.2.11.6 The fire escape should be constructedof non-combustible materials, and any doorwayleading to the fire escape should have the requiredfire resistance.

IS : 1644 - 19(182.11.7 No staircase, used as a fire escape,should be inclined at an angle greater than 45 tothe horizontal.2.11.8 Fire escape stairs should have straightflight not less than 75 cm wide with 20 cm treadsand risers not more than 19 cm. The number

of risers should be limited to I5 per flight.2.11.9 Hand rails should be of a height notless than 100 cm and not exceeding 120 cm.2.11.10 Spiral Fire Escape - The USC of spiralstaircase should be limited to occupant load andto a building not exceeding 9 m in height unlessthey are connected to platforms, such as bal-conies and terraces to allow escapees to pause.2.11.11 Spiral fire escape should be not lessthan 150 cm in diameter and should be designedto give adequate headroom.

2.12 Roof Exit - In all buildings over threestoreys in height where the slope of the roof isless than 20 degrees, direct access to the roofsshould be provided from the street by means ofa stairway. Where roofs are used as roof gardensor for other habitable purposes, sufficient stair-ways should be extended to them to providenecessary exit facilities required for such anoccupancy.NOTE-This does not apply to A-2 and A-4 occu-pancies up to 15 m height.

2.13 Horizontal Exits2.13.1 The width of horizontal exit should bethe same as for the exit doorways ( see 2.8 J.2.13.2 A horizontal exit should be equippedwith at least one fire door of self-closing type.2.13.3 Floor area on the opposite or refugeside of a h6rizontal exit should be sufficient toaccommodate occupants of the floor areas served,allowing not less than 03 m2/person. The refugearea into which a horizontal exit leads should beprovided with exits adequate to meet the require-ments given in this standard. At least one of theexits should lead directly to the exterior ofbuilding or to a street.2.13.4 Where there is a difference in levelbetween connected areas for horizontal exits,ramps, not more than I in IO in slope should beprovided; steps should not be used.2.13.5 Doors in horizontal exits should beopenable at all times from both sides.

2.14 Fire Tower - Fire towers are the preferredtype of escape route for storeyed buildings andtheir application should be considered as thesafest route for escape. Their number, locationand size should depend on the building concerned,and its associated escape routes.

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Bureau of Indian StandardsBIS is a statutory institution established under the Bureau of ndi un St andar ds Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goodsand attending to connected matters in the country.CopyrightBIS has the copyright of all its publications. No part of these publications may be reproduced in any formwithout the prior permission in writing of BIS. This does not preclude the free use, in the course ofimplementing the standard, of necessary details, such as symbols and sizes, type or grade designations.Enquiries relating to copyright be addressed to the Director (Publications), BIS.Review of Indian StandardsAmendments are issued to standards as the need arises on the basis of comments. Standards are alsoreviewed periodically; a standard along with amendments is reaffirmed when such review indicates thatno changes are needed; if the review indicates that changes are needed, it is taken up for revision. Usersof Indian Standards should ascertain that they are in possession of the latest amendments or edition byreferring to the latest issue of BIS Handbook and Standards Monthly Additions.

Amendments Issued Since PublicationAmend No. Date of Issue Text Affected

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