Interpretation of Passive Fire Requirements

in the UBBL 1984

Ar Chong Lee Siong APAM MIFireE

PAM CPD 3 November 2012

Uniform Building By-Laws 1984

is a

“PRESCRIPTIVE” BUILDING CODE

•Compliance with this code is a requirement by law •Sets rules and regulations on the application of the code •Provides pre-determined prescriptions

The prescriptions are absolute : no smaller than…….. no bigger than…….. no shorter than…… no longer than…… or no less than and no more than.

CONCEPTS OF FIRE SAFETY

1 EVACUATION

2 PASSIVE CONTAINMENT

3 ACTIVE INTERVENTION

4 ACCESS FOR FIRE FIGHTING AND RESCUE

• EVACUATION

• Detection

• Alarm

• Exits

• Travel distance

• Components

• Capacity of exits

Accepted assumption in designing for safe evacuation:

“Only one fire at one location at a time”

exit

• Final exit

• ‘Alternative exits’

• Storey exit

• Horizontal exit

• Exit route

Final exit

• UBBL 133 – interpretations

• Final exit refers to the threshold that separates “still within the building” and “out of the building”. The liability of the design for evacuation from the building ends at this point.

‘Alternative exits’

• UBBL 166

• This is the primary concept for safe evacuation. Every floor space shall be provided with at least two exits on the basis that if one exit is inoperable, the other exit can serve the function.

• This ‘designing for redundancy’ principle applies to all aspects of evacuation.

Final exit

Final exit

Final exit

Alternative exits

Alternative exits

Horizontal exit

• UBBL 171

• Exits that lead to an adjacent (horizontal) separated compartment within the same floor

Horizontal exit

Protected staircase

to final exits

Compartment wall

Protected staircase

to final

exits

Horizontal exit

Storey exit

• UBBL 167, 174

• Exits from a floor which is of a different level from the final exit, or, if on the same level, a distance away from the final exit.

• A storey exit is to lead to a final exit.

Exit route

• UBBL 133 – interpretations

• UBBL 169

• the protected passage from a storey exit that leads to the final exit.

• Can include spaces that are designated as areas of refuge anywhere between the storey exit and the final exit

Travel distance • UBBL 165

• 7th Schedule

• Dead end • initial travel distance before a point where an alternative path becomes

available

• Direct distance • Stipulates that travel distance must be measured along the actual path of

travel

• Open plan • Where an actual path of travel cannot be determined, the direct distance

can be measured as a straight line direct to the exit. Permitted travel distance is then reduced to 2/3.

Evacuation : small area

Evacuation : larger area

Evacuation : multiple areas

Final exits

UBBL 165 (B) Max 15m if room < 6 pax

To comply with dead end and travel distance Max distance is 15m within room plus max allowable travel distance From door of room to final exit

Evacuation : multiple areas

Horizontal exits

storey exits

Horizontal exits

1 2 3

Horizontal exits

1 2 2

Storey exit

Storey exit

For floors up to 9m from

ground floor, mezzanine floors may be

permitted to be up

to 50% of the area of floor below.

For mezzanines above 9m from ground level,

a floor area of upto 1/3 of floor area below

may be permitted.

Diagramme 4.4.5.9.

Egress through

unenclosed openings

(mezzanines)

Permitted

Alternative

Route

components

• Exit door

• Exit discharge

• Protected corridor

• Protected staircase

• Balcony approach

• Single staircase

Exit door, exit discharge

• UBBL 173

• UBBL 186

• UBBL 193

• UBBL 133 - interpretations

• ‘Door’ refers to the physical door installed at an exit, and all its functional components e.g. locksets, latches, hinges and closers

• ‘discharge’ refers to the ‘doorway’ or threshold of an exit

Exit door, exit discharge • Not all fire rated doors are exit doors

• Not all exit doors need to be fire doors

• Not all doors need to be exit doors

• Not all doors can be exit doors

• Exit doors must always be able to be opened (without undue effort) at all times

• Exit discharge must always allow the passage of people at all times

• ‘Exit’ in this context means storey exit, horizontal exit or final exit

Evacuation : separation of routes

Final exit Final exit

Protected corridor, protected staircase

• UBBL 133-interpretations

• UBBL 157, 189, 190, 191

• While not expressed, it is inferred from the UBBL that all components that form the Exit Route shall be of protected construction.

• Using the same inference, ‘protected’ shall mean ‘enclosed’, ‘separated’ or ‘isolated’

section B-B 2m

2m

2m

2m

2m

2m

Openings for toilets

can be formed

9m Opening more than

9m below can be

formed

Fixed openings

with wired glass

allowed

section a-a

Zone where

opening

not permitted

PLAN

A

A

B B Protection for External

Escape Staircase

By-Law 191 ensures that an

external staircase used for escape

purposes will remain protected

from fire exposure originating from

the building. Therefore, a zone of

protection is extended from the

staircase both upwards and

downwards to ensure safe passage

during a fire.

The following illustrations show

the zone where no opening shall be

formed or only toilets or other

protected area openings or

openings with wired glass and kept

permanently closed can be allowed

to be formed.

Single stair

• UBBL 194

• Special provision for the common ‘shop-house’ design

• Usage limited to shop (ground floor only), residential or office.

• Uppermost floor level limited to 12m

By-Law 194 stipulates when a single staircase may be permitted. Essentially, this is only

allowed where the occupancy above ground level is confined to either domestic or office

purposes. The ground floor may be used for shops or car parks. (shop offices, shop

houses)

All elements of structure shall have a FRP of not less than one hour except the enclosure

for the staircase at the ground floor where the wall shall have an FRP of not less than

two hours, assuming the ground floor will not be used for residential purposes.

12m

max.

12m

max.

Diagram 4.4.8.2.

Maximum travel distance

not more 12m

Assumed Room of occupancy < 6

Shop or car park

Diagram 4.4.8.1.

Height of topmost floor

of building with single

staircase

Height of

topmost floor < 12m

Domestic or office use

SINGLE STAIRCASE PROVISION UBBL 194

Capacity of exits

• UBBL 7th Schedule

• UBBL 175, 176, 178

• Occupant load

• Exit width

• Application of horizontal exit

Sample calculation

Scenario 1: upper floor assembly area in an institutional building

50m

20m

Stair A Stair B

Lobby C

Sample calculation

Scenario 2: upper floor assembly area in an institutional building

35m

Stair A Stair B

Lobby C

20m

15m

door D

Final exit

Exit route

horizontal exit

storey exit

Final exit 250 pax

400 pax

200 pax 150 pax

300 pax

200 pax

• Size limitations of ‘compartments’

• Fire Resistance Ratings of ‘elements of structure’

Compartmentation

• To contain the spread of fire from point of origin

• To limit the potential size of the fire

• To separate areas of different levels of hazard

• To separate areas for safe exit, evacuation or refuge

• To limit threat to the structural integrity of the building

• To allow sufficient time for safe evacuation, active extinguishment of fire and rescue.

Compartmentation

Accepted assumption in designing for safe evacuation:

“Only one fire at one location at a time”

Primary objective of compartmentation:

“To contain the one fire within the one location at all times”

COMPARTMENTS, ELEMENTS OF STRUCTURE AND FRP

215(2) : reference to height, by building only

215(1) : reference to elements of structure, by building, or by compartments

137 : floor to floor compartment for buildings > 30m height

138(b) : floor and walls separating flats

138(c) : floor and walls separating purpose group

138(d) : floor separating basements

Service apts

Offices

Shops

Carpark

Cineplex

Max 25mm (/)

FIRE APPLIANCE ACCESS

Refers to an area “Access Way” specifically allocated for the

parking of Bomba appliances during fire fighting and rescue operations. UBBL 140 “Access Way” (street, road or open space) is to be provided as a proportion of the perimeter of the building, with reference to the volume of the building.

EXTERNAL ACCESS

Access for emergency and rescue vehicles, equipment and personnel

•Roads •Pavements •Parking

Availability of water : •Hydrants •Storage tanks •Lakes, rivers, ponds

And access to fire fighting systems in the premises

Clarity of : •Type of building and function •Configuration of building •Location of fire control panel •Location of breaching inlets and pump rooms

AT THE PREMISES

Access into the building •Protected passage •Protected stairs •Firemen’s lift •Fire fighting lobby

Pressurised Hydrant System

Sprinkler System

Dry Riser system

Wet Riser System

External source of water •Hydrants •Lakes, Ponds, Pools, rivers •Fire Tenders

Fire Fighting Appliance on ‘Access Way’

Internal Systems •Sprinklers •Hose reels •Dry/Wet Risers

Breaching Inlet

Vehicles in use by JBPM : •Motorcycle •Terrain buggy •Rapid Fire Rescue Tender •Fire Rescue Tender •Turntable ladder •Hydraulic platform •Hazmat

Example of Fire Fighting Access Way

Fire appliance access level and Access Way

Access Way at upper ground level

13,000 m3 (1/6)

8,600m3 (1/6)

36,000m3 (1/4)

Access way at appliance access level

Access way at upper ground level

Access road / ramp Access road / ramp

Access ramp

Access ramp

Command center Breaching inlet Pump room access

Note: Turning provision required for fire appliances if dead end access

exceeds 18 m.

Turning provision can be in the form of hammer-head or turning

circle

Building volume

7,001 cu m

to 28,000 cu m

D

A

B

Isolated site/location

with no adjacent

property/building.

X => 1/6 (A+B+C+D)

Fire appliance

access X

C

C => 1/6 (A+B+C+D)

Appliance access from main road is sufficient if the building volume does not

exceed 28,000 m3.

In the event the 6 m back lane is accessible by fire fighting appliances and the

building volume exceeds 28,000 m3 but is less than 56,000 m3, then,

A + C => 1/4 (A+B+C+D)

Building volume

7,001 cu m

to 28,000 cu m

City/Built up location

with adjacent buildings D

A

B

C

Accessible perimeter

of building

Main road used for

appliance access

if not less than 12m wide

Pavement

6m back lane

D

A

B

D

A

C

Access

road

> 18m

Building volume

56,001 cu m to

84,000 cu m

min. 6m

B + C => 1/2 (A+B+C+D)

C

Fire appliance access Access road

12m

B

6m back lane

accessible to fire appliance

Pavement

Access road

12m A + C => 1/2 (A+B+C+D)

D

Fire appliance

access minimum

6m width

Building volume

84,001 cu m to

112,000 cu m

A + B + C 3/4 (A+B+C+D)

A

B

C

Access road 12m

D

A

B

Building volume

84,001 cu m to

112,000 cu m

B + C + D => 3/4 (A+B+C+D)

C

Access road 12m

A

Building

volume

above

112,000 cu m

Minimum 6m width

Fire appliance access

D B

C

Access road 12m

W2

(min 6m)

L(13m)

L(13m) min. 6m W1

d1

d2

W = unobstructed width of Appliance Access

L = length of largest Fire Appliance (currently 13m)

d - cut-back distance is obtained by intersecting the imaginary corner of a building with

line A - C

The minimum permissible width of a Fire Appliance Access is 6.0m.

The minimum turning radius around corners of buildings shall be provided as follows:

Hydrants should be located:

i) away from obstructions such as street furniture (benches), phone

booths, etc.

ii) not less than 2,000mm from adjacent buildings and overhangs.

iii) between 610mm to 2,400mm from Fire Appliance Access.

iv) away from risks of vehicular damage.

v) not more than 90m apart from each other (in new buildings adjacent

to existing developments, a new hydrant within 45m radius of the new

building).

No overhangs

over hydrants

Verandah

Pavement

Access

Hydrant

Building

> 2m 0.6m to 2.4m

Thank You