section 6 access and egress

8/18/2019 Section 6 Access and Egress

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Section 6: Access and egress

This section will introduce you to:• access and egress

• required exits

• paths of travel

• requirements for exit doors

• stair and ramp design• required signage

• access for persons withdisabilities.


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Intent of Section D

•

This section deals with themovement of people in andaround the building, to ensurethat all parts of a building can beeasily accessed.

• It covers nearly all forms of

vertical and horizontalmovement, and as is the case inother sections of the BCA, placesa great deal of emphasis onegress during a fire.


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Intent of Section D

Most aspects of the movement ofpeople within, or around, a

building are usually catered for inthe functional requirements of

the building itself. Therequirements of the BCA generallyfocus

on the occupant’s safety withregard to the means of entering

(access) or leaving (egress) variousparts of the building.

These provisions cover a fairly wide rasuch as:

• width of corridors

• door opening sizes

• door operations and equipment

• provision of stairs

• stair and ramp design

• provision of safety rails

• number of access points

• access for people with disabilities

• number of and location of exits.

• All of these provisions are intendednormal use of the building. More st

are added for the provision of egre


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In Details

•

Section D should be studied indetail as the requirements havea major influence on the actual

layout of the building.

• The requirements for thenumber and position of stairs,paths of travel, etc., will have asubstantial influence on theoverall configuration and designof a building.

•

BCA will not be lookedby part.

• The focus will be on looverall concepts by disthe central issues ie. dstairs, etc., and highligareas of special signifi


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Intent of Section D

• The requirements placed on egress arequite logical, and are in line with theoverall intent of the BCA (as discussedearlier).

• In a fire situation, the need to quickly findan exit and leave the building safelywithout encountering smoke or fire is notan unreasonable requirement.

• As the number of occupants in a building

increase, greater requirements will bemade on escape routes.

• In the case of buildings where theoccupants are infrequent visitors, theprovision of clear signage to escaperoutes is also an obvious necessity.


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Intent of Section D

•

To identify where specific areasneed to be enhanced toaccommodate the expectednumber of people or situation in abuilding, the BCA again relies onthe Classification of the Building

and the Type of Construction.• If you look at the provisions of

Section D based on this viewpoint,understanding and interpreting therequirements will be much easier.


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Exit travel distance (Clause D1.4)

• The distance of the path of travel is know as

the Exit Travel Distance and is the totaldistance that a person would have to travel toget to an exit. Exit, according to the BCAmeans:

a) Any or any combination of the following ifthey provide egress to a road or open space.

• i) An internal ramp or stairway.

• ii) A ramp.

• iii) A fire-isolated passageway.

• iv) A doorway opening to a road or openspace.

b) A horizontal exit, or a fire-isolatedpassageway leading to a

• horizontal exit.

• The total Exit Travel Distance d

buildings with one exit or• multiple exits and with the Clas

building or part building.


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Figure 11

•

Figure 11 and Figure 12, on thefollowing pages, provide a guideto the maximum Exit TravelDistances in Class 2 & 3 and 5 to9 buildings.

• NOTE: The abbreviation ‘SOU’shown in Figure 11 and Figure12 means Sole-Occupancy Unit,which is a defined term in theBCA.


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Figure 12


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Figure 13

•

Figure 13 gives you an indicationof the reason for requiringmultiple exits.

• The requirements for exitsdepend on the buildingclassification, type of

construction and the number ofoccupants.

• The points given above need tobe assessed using theseparameters.


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Paths of travel

• In a fire situation, evacuation of the building

obviously needs to be by the quickest, andconsequently the shortest route.

• It is unsafe to have people wandering arounda building in a haphazard fashion looking foran exit.

• As a means of achieving a speedy and orderlyevacuation, the BCA requires that an exit pathbe established.

•

This path is referred to as the “Path of Travel”and sets out the actual path people can usewhen exiting a building during a fire.

• The path of travel is also the maximumpermissible distance that the occupants willactually need to travel to reach the outside ora fire-isolated stair, ramp or passage.


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Paths of travel

• In Part D1 the actual construction and various

configurations for the paths of travel arelooked at in detail.

• The intent is to ensure that the actual routethe occupants have to travel will be such that

• the path of travel will:

• Be the most direct route to the outside.

• Not bring the occupants into contact withhazardous

• situations.

• There are no obstructions in the path.

• That the route is easily accessible and easy tofind.

• That the route can cope with the number ofoccupants.


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Measuring exit travel distances

•

For the correct method ofmeasuring Exit Travel Distancerefer to Clause D1-15.

• The following three examplesshow how to measure variousexit distances.


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Dimensions of exits and paths of travel exits (Clause D1.6)• Subclause (a) provides the minimum

height applicable to the path of travel toan exit for all building classes. Note: Thatdoorways in the path of travel arepermitted a slightly reduced height.

• Subclauses (b) to (e) provide theminimum widths for the path of travel toan exit in various locations and buildingclasses.

•Subclause (f) provides the minimumwidths applicable to doorways in the pathof travel to an exit for all building classes.

• Subclause (g) states that a path of travelto an exit must not get narrower as youtravel toward the exit except in twospecified Patient Care locations.


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Activity


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Activity

• Activity – comments

• For Figure 18 the applicais D1.4(c)(ii), ie. Total Trafrom point ‘X’ exceeds 40

• For Figure 19 the applicais D1.5(d), ie. Path of TraExit from point ‘X’ convethan 6.0m.

• For Figure 20 the applicais D1.4(c)(i), ie. DistanceChoice will exceed 20m mfrom anywhere in the shareas.


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Activity Comment

• There are quite a number of requir

associated with this “functionality”intended to ensure that the occupabuilding can physically negotiate th

• As the number of people in the buithen the path of travel must be suitaccommodate them. This is achievethe route is wide enough, and has nin it.

• In the next section dealing with exirequirements outlined relate direct

for the “Path of Travel”. The two aras is most of Section D.

• The examples given in Activity 1 on the previous

page is for a Class 5 building, and suits theparticular requirements specific to the situationshown.

• Naturally the resolutions to meet requirements willvary to meet particular requirements. However,the basic parameters will not. Therefore, just likethe examples in Activity 1 you may have to relocatestairs, etc. to suit particular situations.

• Variations are also possible for different buildingclassifications, and you will have to study Section D

in detail in order to ascertain what requirementsyou need to meet.

• Establishing a path of travel is more than justplanning the route people will take in the event ofa fire. The path must be capable of being used, inother words, it must be functional.


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Exits

• The “Path of Travel” must lead to an exit, but what is an exit?For the general public, exit means the door that leads directly

to the outside. However, the BCA has a much broaderinterpretation of what is an exit. This point is clearly indicatedby the definition given in Section A – A1, which reads asfollows:

• Exit means:

a) Any or any combination of the following if they provide egressto a road or open space.

• i) An internal ramp or stairway.

• ii) A ramp.

•

iii) A fire-isolated passageway.• iv) A doorway opening to a road or open space.

b) A horizontal exit, or a fire-isolated passageway leading to a

• horizontal exit.


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Exits

• The requirements for exits dependon the building classification, typeof construction and the number ofoccupants.

• What needs to be clearly

understood is that an exit is notsimply a door.

• Exit means entering an area whereyou can escape the building.


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Exits

• For example, an exit in 20-storey

building is the door leading into thestairwell. However, it is only an exitif the stair takes you to the groundfloor.

• Depending on requirements an exitmay or may not have to be fire-isolated.

• Figure 22 shows the staircase thatthe path of travel leads to. In thiscase the staircase has to be fireisolated, and as such once peopleare in the actual staircase they areconsidered to be in a “safe” area.


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Exits

• It should be noted that thestaircase must lead direct to theoutside and not be required toenter another floor of the building.

• However, not all stair cases needbe fire isolated, such as Class 5 – 9

buildings under three (3) storeysand Class 2 & 3 buildings underfour (4) storeys. These are referredto as non-fire isolated stairs andtravel distances are found in D1.9.

• The requirements for firstairs are found in D1.7. external stair in lieu of a isolated stair is a stair coexternal to the building wisolated stair is required

•

However, it has the samesafety as if it were a fire stair. Details of this stair at Dl.8.


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Exits

• There are also requirements on the

doors themselves with regard todirection of swing, lockingmechanisms and door closers.

• The need for this is considered tooriginate from a fire in a Parisnightclub in the seventies.

• In that fire, 90 people died becausethe exit doors opened into thenightclub. The people could not getout of the building because therewere so many people pushing atthe exit doors.

• For residential type build

as low-rise units, the reqon egress are not as strin

• For example, Part D1.3 inthat for Class 2 buildingsrequired exit needs not tisolated if it is three stor

• For Class 3 buildings, thcan go up to three storey


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Horizontal exits

• A horizontal exit in the BCA

refers to a doorway leading to anarea that is considered to besafe eg. a fire-isolatedpassageway, ramp or separatefire-isolated compartment.

• Although this appears to be thesame as what was discussedearlier, it is quite different, as itis possible to use another fire-isolated part of the building as asecondary area to escape to.

• For example, assume t

building has a firewall two sections. The doorthe sections can be useexit point.

• You should however, bin using this method asrequires you to meet stravel distances to gainthe outside.


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Horizontal exits

• In establishing the requirements for paths of traveland exits, the building classification and type ofconstruction play an important role.

• However, as has already been indicated, thenumber of occupants in a building or on a floor ofa building also has a major impact.

• The method used to establish how many peoplewill be in a building is given in Table D1.13.

• This table calculates the number of occupantsbased on a floor area for each person:

•

For example if the building or floor has an area of200 m² and according to the table, 1 person willoccupy 10 m², then all design parameters mustallow for 20 people.

• It is often argued by owners and dethe outcome of using the BCA calcit gives a much higher number thabe using the building. In some casetrue.

• However, the BCA logic is that the eventually change ownership or thoperation resulting in a change of toccupants.

• Naturally under the performance cpresent a case, and in some cases yBut this will then result in a restrictnumber of occupants in the buildinon the Certificate of Classification fbuilding.

• The table used to establish the numoccupants in building (Clause D1.13used to establish the construction oalso used in Section F to establish tsanitary fixtures required in a build


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Part D Construction of exits

• Exits are for all emergencies not just for fire emergencies. That iswhy they are called emergency

exits not fire exits. However,fire is the one most in peoplesmind. As a designer, you should

think past this.


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• The construction of the components of

the paths of travel. The intent is to ensurethat escape routes will provide a safemeans of travel and that this route willnot become a hazard during the course ofa fire, or any other emergency.

• Clauses D2.2 to D2.6 looks at the actualconstruction and materials used for stairs,ramps and the walls that will form theescape route areas.

• The primary aim is to make the fittingsalong the path of travel non-combustible,and to ensure that smoke cannot enterstairwells or passageways that are to beused as required exits.

• The requirements in Clauses

D2.8 are aimed at ensuring tfire sources are not incorporareas forming part of the exiof travel. If taken in context trequirements are very logicaintended to prevent the posssource from being incorporatareas”.

• Services and fittings such as e

wiring, fuel lines or ducting, weither start a fire or allow a fcarried into the “safe area”.


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• Clauses D2.9 and D2.10 is

intended to ensure that the pathof travel is correctlydimensioned to cater for thenumber of occupants that couldbe expected to use it during afire.

• Clauses D2.13 to D2.21 also dealwith this aspect by indicating thedimensions and fittingsassociated with stairs, ramps anddoors.

• The emphasis has so f

on situations dealing wof travel relative to firsituations.

• Clauses D2.13 to D2.18relate to fire situationto areas where there irequirement for fire isrequired exits.


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Stairs and ramps

• The performance requirements relating toegress within, and around buildings are statedin Clause DP1 to DP9. Many of these aspectshave already been dealt with, however, theemphasis has been on the movement ofpeople in a fire situation and not in thecontext of the daily routine.

• The movement of people in a building can bedivided into two parts ie. horizontal andvertical. Horizontal movement is achieved bypassageways and corridors, with doors and

walls used as a means of regulating the flowof traffic.

• For this type of movement, the of the BCA are fairly straightforwconcentrate on ensuring that codoors are wide enough. For northere are not a great deal of reqplaced on these aspects, the grethe legislation concentrates on of a fire.

• The requirements for vertical mbuilding are more extensive andnormal usage and egress in case

Section D all requirements relatramps. Lifts are dealt with in Paquite logical as Section D conceegress during a fire and lifts maas means of escape.


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Stair design

• The BCA requirements for stairs are

intended to provide a safe and easyaccess to different levels. Toachieve this, a set of parametersrelating to the height of the risersand the lengths of the treads aregiven (refer to Clause D2.13 andTable D2.13).

•

The pitch or steepness of the stairsare regulated by using the formula2R + G (2 x rise + going), ensuringthat a staircase stays withinacceptable “comfort” conditionsfor the user (Clause D2.13).

section 6 access and egress

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