Layout of the code
Section 7 – User responsibilities
8. The fire alarm contract and definition of responsibilities
The code attempts, in the manner in which it is subdivided, to reflect the way fire alarm contracts operate. In the most complex cases, a single main contractor is often responsible for the construction of a new building. The main contractor will subcontract the electrical installation to an electrical contractor. The electrical contractor will often take on responsibility for the installation of the fire alarm system. The design of the fire alarm installation (and the electrical installation in the building) will often be the responsibility of a consulting engineer. A specialist fire alarm manufacturer, or a fire alarm contractor (who may, or may not, be the manufacturer of the system), may then be contracted by the electrical subcontractor to supply and commission the system.
Ultimately, maintenance may be undertaken by the company that supplies and commissions the system, or by a yet further party.
In the experience of the author, it is ‘supply and commission’
contracts of the type described above that have the most potential for inadvertent non-compliances with BS 5839-1 and for contractual disputes. Often, in the past, the ‘designer’ has merely included a page or two of description of the fire alarm system within a much longer and more general electrical specification. This description will largely rely on a requirement for compliance with BS 5839-1, although drawings are often prepared showing the locations of devices.
Problems can then arise if the specification contains requirements or design detail that do not, in fact, comply with the code. For example, a non-fire resisting cable might be specified, contrary to the recommendations of the code, detector siting and spacing, as shown on the drawings, might not comply with the code, and sounder layout may be insufficient to achieve the required sound pressure levels. The question then arises as to whether the ‘designer’ can rely
on the reference to BS 5839-1, making all errors the responsibility of the installer, or whether the installer is correct to adopt the non-compliances with the code explicitly contained within the specification.
Further complications can arise from the fact that the specialist company responsible for supply and commission of the system may have given advice on the design, and, in previous versions of the code, their commissioning engineer was expected to issue a certificate of compliance with the code as part of the commissioning process.
For these reasons, the current version of the code endeavours to create ‘fire walls’ between the responsibilities of the various parties.
However, clause 6 of the code contains recommendations regarding the consultations that should then take place between the various interested parties. The code recommends that, before any order is placed for the system, the responsibility for system design, installation and commissioning should each be clearly defined and documented.
Even before design begins, the code recommends that the user or purchaser of the system, or someone on acting on behalf of these parties (such as a consultant) should ensure that, to the extent appropriate, there is consultation with the authorities responsible for enforcing fire safety legislation and the property insurer. It is important that, in these consultations, account is taken of the fire safety strategy proposed for the building.
A fire alarm system is not an end in itself; it is merely there to support the fire safety strategy for the building. Yet, a common error in approach is to permit a designer to specify the system with attention mainly focused on matters of engineering, rather than the principles of fire safety. It is not unknown for a user to endeavour to formulate fire procedures around a system that has been provided, rather than determining the fire procedures and arranging for a system that can suitably support them – a clear case of the tail wagging the dog!
The code then advocates that the designer should, to the extent appropriate, consult, during the design stage, with the user or purchaser (to ensure that the system will meet the objectives of the end user) and with relevant consultants. The latter may include architects, mechanical and electrical consultants and, in the case of a complex building, fire engineering consultants. At the end of the design stage, the designer then certificates that the design complies with the recommendations of Section 2 of the code, which is, by far, the largest section and deals with all aspects pertaining to design.
Of course, as BS 5839-1 is a code of practice, rather than a product standard, ‘variations’ may be incorporated within the design. Variations may arise simply because the recommendations of the code are unsuitable
The fire alarm contract and definition of responsibilities
for a particular installation. Strict compliance with the code might then result in unnecessary expense, installation difficulties or even (albeit rarely) an inadequate level of fire protection. In the previous version of the code, variations were described as ‘deviations’. However, this term implied shortcomings or errors in design, whereas what are now termed as ‘variations’ are, in reality, aspects of design that are appropriate and intentional departures from the recommendations of the code.
This does not imply that the designer has carte blanche to ignore good practice or design a system that compromises the intended fire safety objective, simply to result in a cheaper system that is easier to install. The code stresses that variations need to be the subject of specific agreement amongst all interested parties and need to be clearly identified in all relevant system documentation, including the design certificate.
The code takes particular note of the fact that, where values are quoted for certain design parameters, including detection zone size, travel distance to the nearest manual call point, maximum area of coverage of an automatic fire detector, minimum sound pressure levels, etc., the figures quoted in the code are often entirely arbitrary. This does not imply that they are meaningless or ‘founded on sand’, but simply that there is little or no engineering or scientific basis for the values given, which are merely the best judgement of experts in the field as to the figure that is reasonable.
Thus, the 2,000 m2 maximum zone size was originally based on an (electrical engineering) limitation on the number of detectors that could be connected on a single circuit in a conventional system. The maximum area of protection that may be disabled in the event of a specified fault condition, as defined in the code, is then based on the fact that, in a conventional system, a single fault on field wiring will not normally disable protection throughout an area greater than a single zone of the system. The maximum travel distance to the nearest manual call point is based on the maximum distance of travel to a storey exit permitted in the design of means of escape; this figure, itself, is somewhat arbitrary.
The code is filled with numerous such arbitrary limitations or recommended performance levels. The implications of this are that minor departures from such arbitrary figures may have little effect on the overall protection afforded by the system. Variations, are, therefore, not necessarily significant and, as the term is used in the code, they are not ‘errors’ in the design.
When the design is completed, and is handed over to an installer, the code advocates that the installer consult, to the extent appropriate, with the designer, the user or purchaser, the supplier of the system, and the
relevant consultants with whom the code also recommends that the designer should consult. In a simple project, there may be very little, if any, need for such consultation. However, as a large project progresses, points of detail often arise where simple consultations with the parties described above may be appropriate.
In order to avoid other disputes during the contract, the code recommends that responsibilities for certain other matters are properly defined and documented. For example, where a fire detection and fire alarm system is to be integrated with a voice alarm system, the code recommends that one organization should take responsibility for the interface connections and all necessary communications between the two systems. This recommendation has arisen out of experience in which, for example, monitoring of wiring between the two systems has been inadequate or non-existent, simply because the interface between the two systems ‘falls between two stools’; the fire alarm contractor often considers this as an input to the voice alarm system and therefore the responsibility of the voice alarm supplier, while the voice alarm supplier considers that the interface is an output from the fire alarm system that should be monitored by that system. The manner in which this should be dealt with is addressed in BS 5839-8.16
Often a fire detection and fire alarm system is interfaced with other systems associated with life safety (see Chapter 9). For example, the system may be required to operate a fire extinguishing system or charge a pre-action sprinkler system. If a smoke control system is provided, it will normally be triggered by automatic fire detection. It is also common to arrange for lifts to ground automatically on operation of the fire alarm system. Since, in each of these cases, the other system with which there is an interface is often the responsibility of another party, the code recommends that the responsibility of each organization (the installer of the fire alarm system and the organization responsible for the other system) should be clearly defined and documented.
A common omission from the fire alarm system, as handed over, is a zone plan. The omission often arises because its provision only arises at the end of an installation contract, but it is discovered, too late, that there are no drawings of the premises that can be marked up. Accordingly, the 2013 edition of BS 5839-1 recommends that responsibility for provision of a zone plan needs to be defined at an early stage of planning of a fire alarm installation.
16 BS 5839-8, Fire detection and alarm systems for buildings — Code of practice for the design, installation, commissioning and maintenance of voice alarm systems.