Alternative approaches to address building modifications and compliance for fire safety
Under the Singapore Fire Safety Act, it is mandatory that all fire safety works must be submitted by the Qualified Person (QP) in compliance with the prevailing Fire Code. In circumstances whereby there is any non-compliance that may be due to inadequate provisions, existing site constraints or other unforeseen factors, a waiver application must be submitted to SCDF (AHJ) for approval.
SCDF has permitted a list of non-compliances that need fire engineering assessment to be carried out by a registered Fire Safety Engineer (FSE) in support of the waiver application to be submitted by the Qualified Person (QP).
Unlike full performance-based design submission process whereby Fire Engineering Design Brief (FEDB) and engagement of 3rd Party Peer Reviewer is necessary, Fire Engineering Assessment + Waiver Application is an alternative quicker waiver submission platform to address certain deviations that require fire and smoke assessment involving CFD modelling and Evacuation Modelling.
With the prevailing building codes and standards changing to address new technologies and market trends, existing buildings may be outdated or deemed to be non-compliant during the stage of upgrading. Innovative fire safety engineering designs for existing buildings are therefore required to ensure continuity and code compliance.
Through in-depth knowledge of prescriptive and performance-based approaches, SHEVS can provide the most appropriate and effective Fire Engineering Assessment to seal the gaps for code compliance.
Common Deviations and Non-Compliances
Extended Discharge Distance & Inadequate Air Well Size
CFD modelling for a truck fire to assess the effectiveness of the high wall as a heat shield to protect the occupants using the open staircase for evacuation.
Due to the existing conditions of the development, a code-complaint air well size and protected corridor for occupant discharge from the exit staircase to external are not feasible.
During the upgrading of existing buildings to suit the market trends and potential changes in use, inevitable non-compliances with the prevailing fire codes may arise.
Therefore, fire safety engineering approaches may be adopted to demonstrate that an acceptable level of life safety criteria can still be met in accordance with the performance objectives of the fire codes.
CFD Modelling to assess Tenability Limits
Assessment on the tenability limits in terms of visibility, temperature and radiation effects on the occupants in the discharge path due to the extended discharge distance and inadequate air well size.
The CFD results have demonstrated that tenable conditions are maintained in the occupant discharge path as follows:
Occupant Load exceeds Exit Capacity for existing Malls
For existing buildings, alterations, additions and upgrading works are commonly carried out to suit the market trends and the stakeholders’ ambitions. Due to the change of use in occupancy, the occupant load may exceed the exit capacity of the existing exits and exit staircases.
Computer evacuation modelling can be used to evaluate alternative options to address such deviation in lieu of having additional exit staircases for compliance.
Sustainable fire engineering solutions are designed to cope with future alterations and additions to suit the market trends and the stakeholders’ ambitions.
The fire safety measures are implemented in compliance with the prevailing building codes and standards to ensure continuity and code compliance.
No Cross Ventilation for Corridor
While prescriptive and traditional fire code compliance can be applicable for many conventional buildings, these codes may hinder and restrict the building designs to suit other building regulation as well as the end-users’ requirements.
The corridors of Kwong Wai Shiu Nursing Home do not have adequate ventilation openings for cross-ventilation.
CFD modelling was used to demonstrate that the tenability limits are maintained at 2.5m AFFL for safe escape at the corridors.
Occupant evacuation modelling is simulated to demonstrate that all occupants can evacuate safely under tenable conditions during a fire scenario.
No Sprinkler Provision for External Corridor
Fire engineering assessment was conducted to ensure tenable conditions are achieved in the external corridor for escape.
Qualitative analysis was also carried out based on mitigating measures such as adequate natural ventilation openings for smoke discharge as well as restriction of commercial activities and combustibles.
The day-to-day natural ventilation openings were considered as natural smoke exhaust openings during a fire situation. Sensitivity studies based on CFD modelling with wind effects were also conduct to test the effectiveness of the natural smoke ventilation system.
Innovative fire safety engineering designs for existing or new development to ensure continuity and code compliance.
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