Introduction
Fire engineering has been widely adopted in Hong Kong since the early 90s. Fire Engineering refers to the application of engineering principles, rules and expert judgement, based on a scientific appreciation of the fire phenomena, and the effects of fire as well as the human behaviour towards fires in formulating a fire safety solution. In this regard, fire safety in buildings that have adopted fire engineering approach is a dynamic interaction between building construction elements, the provision of fire service installations, building management, occupant characteristics and fire service intervention in the case of a fire.
The Code of Practice for Fire Safety in Buildings (Buildings Department, 2011) provides the performance requirements as well as the prescriptive requirements (Deemed-to-Comply provisions) for achieving an adequate level of fire safety in buildings. If there is genuine difficulty in complying with the prescriptive requirements because of specific constraints, such as the building size, use, complexity or location, an alternative solution could be adopted on the condition that it is proven to comply with the performance requirements in the Code. When adopting a performance-based approach, the Building Authority will normally accept a level of performance not inferior to that of the prescriptive provisions, which is considered as a benchmark on the acceptable level of fire safety.
Importance of the Engagement of Different Stakeholders
Based on a fire engineering assessment, a performance-based design is adopted for premises with several bounding conditions. These bounding conditions are a set of fire safety provisions that must be maintained throughout the life of such buildings. The performance-based fire safety design will become invalid if the bounding conditions are altered.
A holistic approach that involves close coordination of all relevant stakeholders from the design stage to the subsequent compliance of the bounding conditions throughout the life of the building should be strictly implemented. Authorised persons, as well as fire engineers should engage the stakeholders at an early stage of the project. Through the formulation of maintenance and management procedures together with the support of owners and property managers, they will be aware of the risks involved and the rationale of the mitigation measures. This will also help to ensure that the bounding conditions adopted by the fire engineers are realistic and practicable for the end users. It will also reinforce the commitment of the end users to sustaining the fire engineering solutions and in turn enhancing the fire safety of the buildings.
Roles of Stakeholders
The roles of the major stakeholders in buildings with performance-based designs are briefly discussed below:
Regulators
As the regulators in building fire safety, the Building Authority and the Fire Services Department (FSD) have made efforts to facilitate the adoption of performance-based design in buildings. Significant manpower resources have been deployed on processing building plans, vetting fire engineering reports and conducting acceptance inspections. Regular reviews have also been conducted to streamline and improve all relevant processes. With a view to ensuring a healthy development of the fire engineering approach, the controlling authorities engage proactively with stakeholders, such as developers, authorised persons, fire engineers and related professional bodies through regular technical seminars and meetings. This is beneficial for all parties concerned and essential for the proper and sustainable development of fire engineering in Hong Kong.
The revised application procedures for inspection and testing of Fire Service Installations and Equipment (FSI) in New Buildings issued by FSD has come into effect on 1 May 2020. Registered Professional Engineers (RPE) shall certify that the FSI involving staircase pressurisation systems, dynamic smoke extraction systems, water mist system or other FSI fall under RPE’s purview to be inspected and tested are operating in accordance with approved design and in full compliance with the FSD requirements. This new procedure has highlighted the role of RPE in practicing Fire Engineering in Hong Kong where RPE(Fire) is relevant in this context.
Authorised Person/ Fire Engineer
In the Code of Practice for Fire Safety in Buildings (Buildings Department, 2011), it stipulates that “a performance-based approach using fire engineering can be adopted to formulate an alternative solution where there is genuine difficulty in complying with the Deemed-to-comply provisions”. Building professionals should carefully assess the necessity to adopt a fire engineering approach, since the crucial prerequisite is “difficulty in complying with prescriptive provisions”. For example, if the adoption of a fire engineering approach involves the exemption of prescriptive requirements on passive fire safety provisions, including substandard fire barriers or elongated means of escape, the over-reliance on fire service installations could give rise to safety concerns. In the event that some of the fire service installations become defective or are under maintenance, fire safety issues will arise due to the higher risk associated with the larger compartment or longer evacuation distance. In order to guarantee a higher degree of reliability, authorised persons or fire engineers should incorporate higher safety margins and safety factors to cater for relevant uncertainties or changes in the design parameters.
Furthermore, the validity of the assumptions and design parameters are decisive factors in determining the practicability and accuracy of fire safety derived from modelling and calculations in the fire engineering design. The fire safety performance of building materials may deteriorate if any of these assumptions and design parameters is found to be incorrect. Thus, with a view to avoiding potential conflicts and for better coordination, fire engineers and other building professionals should be involved to ensure that realistic assumptions and practical design parameters are applied in the initial design stage.
Owner of Building/ Property Manager
For buildings with performance-based designs, building owners and property managers may directly or indirectly affect the compliance with bounding conditions. The owners and property managers should ensure that the strict implementation of fire safety management plans throughout the life of the building, such as maintaining good housekeeping, prohibiting unauthorised building alterations, arranging proper maintenance of fire safety provisions and conducting regular fire drills. However, the owners and property managers may not endeavour to sustain the fire engineering solutions if they are not fully aware of the associated fire risks. In this light, effective training for management staff regarding fire safety management plan should be conducted regularly to ensure the proper compliance of bounding conditions.
Based on the finalised fire engineering report, the authorised persons would specify the bounding conditions in the approved general building plans, the fire safety management plan and the deed of mutual covenant to guarantee proper compliance. For any changes in the active and passive fire safety provisions, the owners and property managers should check against the bounding conditions for compliance throughout the lifetime of the building, and they should review the bounding conditions at least annually.
If there are changes on ownership or property management agencies, attention will be drawn at the handover of all relevant information and requirements of fire engineering design and the fire safety management plan and building alterations that may affect the fire engineering design assumptions and parameters.
The Fire Services Operations and Maintenance Booklet recently released by the Electrical and Mechanical Services Department of the HKSAR Government provides an introduction and understanding of more efficient processes and procedures for operating and maintaining fire services systems in buildings. It describes the important drivers for a building to perform efficiently and safely and the 15 key attributes for implementing good performance operation and maintenance of fire services systems in buildings. Owners and property managers would be benefit from the improved building’s safety, sustainability operational cost savings and improved system reliability with operation and maintenance guidance provided in this booklet.
Conclusion
To cope with the advancement of building design in Hong Kong, codes on the fire safety requirements are revised from time to time by the local authorities. With the adoption of a fire engineering approach to fire safety design, compliance with prescriptive requirements is not the only accepted way to achieve the objective of fire safety. By accepting performance-based design, simply relying on the enforcement of passive and active fire safety provisions are not sufficient to safeguard the standard of building fire safety. Fire engineering assessments and fire safety management plan should be regarded as live documents. Those documents should be reviewed according to the prevailing circumstances in order to maintain the standard of fire safety in buildings. It is essential that the information on alternative fire safety measures devised by fire engineers or professional bodies should be delivered to owners of building or property managers. In conclusion, the engagement of stakeholders who actually implement the fire safety management plan is crucial to the sustainability of performance-based building design and the practice of fire engineering in the long run.
By Ir Ronald WONG from the Fire Division of the HKIE
