Core of High-rise buildings of Dhaka City - II

(Part 1 appeared on 9 April 2004)

Extract from the Building Construction Rules,1996 that are

relevant to today's discussion: Building Construction Rules, 1996 (from original in Bangla)

Framed under Building Construction Act, 1952

BTA Tower

Persons qualified to sign and submit drawing

* Residential building above five stories & all other buildings and building along VIP roads can only be designed by degree architect

Emergency exit & other necessary arrangements

* Emergency exit, separate from stair and lift lobby, must exist within 25m from any point on a floor.

* Elevator/escalator will not be considered as emergency exit.

* Necessary number of fire extinguishers or alternate arrangement in any visible space, with written operational instruction, and fire alarm for quick exit must be provided.

Special rules for 7-storied or higher buildings

* Elevator

* Electricity generator for emergency lighting to staircase, corridor, elevator, water pump, kitchen, etc.

* Fire prevention and control measures as per National Building Code and Fire Services

* For aeroplanes - RED security light in buildings above 45.70m (150')

* 10-storied or higher buildings

* OPEN SPACE: Rear - 3.00m; Sides - 2.50m

* Community space - 5% of total floor area; not on the roof

Mascot Plaza

General information:

* Building name: MASCOT PLAZA

* Building type: Commercial

* Storey : 15

* No. of lifts: 4

* Main stair: No separate main stair (one stair only upto 3rd floor)

* Fire escape: One

Criticism:

* This building has two stairs. One stair goes up to third floor and another runs all the way.

* The stair which runs all along is termed as the 'Fire Escape" and is located at the lift lobby.

* But the function of this stair as a fire escape could be seriously questioned because:

--To reach the stair one has to cross the lift lobby through which fire travels the most. It is required in Rajuk Building Construction rule that there should be an emergency exit separated from the main lift and stair lobby.(rule 17/1,pg.8)

--Again emergency lobby should not reach the basement but here it does.

--The fire escape opens at the ground floor lift lobby not giving access to any safe place.

--Absent of a Standard fire door.

General information:

* Building name: HOTEL SARINA

* Location: Kamal Ataturk Avenue, Banani

* Building type: Residential Hotel

* Storey : 22

* Office space per floor: 3825 sft

* No. of lifts: 3 ( 2 circulation lifts and 1 service lift )

* Main stair : No separate main stair only one stair as fire escape

* Fire escape: One

Criticism:

* -This building has only one stair , termed as "Fire Escape".-But according to The "Rajuk Building Construction Rules, 1996",rule no. 17/1 (pg.8), "each building should have an emergency exit separated from the main lift lobby and stair lobby, within 25m (75') from any point of the building."

* If this stair is the emergency exit then this building doesn't have any main stair. its vertical circulation is solely dependent upon the two passenger lifts and one service lift.

* Again this emergency exit, though within 35' from any point of the building, is just beside the lift lobby. The emergency door opens at a place which is not separated from the lift lobby. In case of fire hazard the workability of this stair as a fire escape is seriously jeopardized due to this non separation.

* Has no fire lobby.

* The rule of emergency exit says that all ppl should reach to safety within 2.5 minutes From this the width of the stair is calculated. Standard is, a 22" stair enables 40 persons to reach safety within 2.5 minutes.

According to the standard this building, with an occupancy of around 230, requires a stair of 126". That means atleast two stairs with 5' width But it has only one stair of 3'2".

* Emergency exit should not reach the basement. But here, as there is only one stair, it reaches the basement.

Rupayan Center

General information:

* Building name: RUPAYAN CENTER

* Location: Mahakhali, Wireless gate

* Building type: Commercial ( shopping cum office)

* Storey : 22

* No. of lifts: 3

* Main stair : One

* Fire escape: One

*Crticism:

* Though this building has a separate fire exit, its workability as an emergency exit could be seriously questioned

* The fire exit shares a common lobby with the main stair and lift core. In time of emergency one has to cross the lift lobby which is, as said earlier, the most vulnerable area during a fire attack.

* It has no standard fire to resist fire attack.

* It opens at ground floor lift lobby instead of any safe access.

* The diameter of the stair is 5'2" and riser is 10".Thsi proportion is very much unusual and puts its workability under serious question.

Concord Regency

General information:

* Building name: CONCORD REGENCY

* Location: Panthapath

* Building type: Mixeduse

* No. of lifts: 3 ( 1 capsule lift, 2 passenger lifts)

* Main stair : One

* Fire escape: One

Criticism:

* This building also has the same problem of having two stairs too close. Meaning sharing a common lobby. If fire attacks at this lobby then there is no escape way from any other part.

* A highrise building should be provided with minimum two stairs in opposite direction. So that in case of emergency atleast one could be used. Having two stairs sharing the same lobby is like having one stair , none of them could be used if the lobby is under attack. Which is very much possible cause fire travels fastest through the lift core.

* Again the fire escape reaches the basement which it should not.It should ive access to a safe place.

Sonar Tori

General information:

* Building name: SONAR TORI

* Location: Banglamotor

* Building type: Commercial office

* Storey : 18

* Office space per floor: 3751 sft

* No. of lifts: 2

* Main stair : One

* Fire escape: None

Criticism:

* This 18 storied building has only one stair.

* Shares a common lobby with the lift core.

* One has to cross the lift lobby to reach it.

* This only stair is not clearly discernable and accessible from al the parts it serves.

* It has no fire door or fire lobby.

* If the lobby is under fire attack then there is no means of escape for the occupants of this building.