What is a temporary or modular building in terms of fire prevention?
A temporary building is a structure intended for time-limited use: site hut or construction office, temporary accommodation module, marquee or event structure, mobile care unit installed as an extension to an establishment. Belgian regulations do not make fire prevention obligations dependent on whether the construction is permanent or temporary, but on its actual use: as soon as it accommodates workers or the public, it falls under the same safety principles as any other building. The occupation duration, number of people present and materials used (canvas, wood, metal framework) are the criteria that the emergency zone (hulpverleningszone) takes into account to assess the applicable level of requirement.
What Belgian regulatory framework applies to temporary installations?
Two texts structure fire prevention for temporary installations in Belgium, depending on whether it is a workplace or a place accessible to the public. The Royal Decree of 7 July 1994 establishing basic standards for fire and explosion prevention applies to buildings without excluding those of a temporary nature, with the emergency zone assessing on a case-by-case basis the measures appropriate to the structure concerned. For construction sites, it is the Code on Well-being at Work (Book III, Title 3, fire prevention in workplaces) that frames fire safety for installations occupied by workers, regardless of the site duration. No single specific text governs event structures: it is the prior advice of the emergency zone that sets concrete requirements, by analogy with the principles of basic standards.
What are the minimum detection and alarm requirements for a temporary structure?
Minimum detection requirements for a temporary structure are determined by proportionality to risk: number of occupants, operation duration, presence of night staff, nature of materials and activities (temporary kitchen, storage, generator set). Standard NBN S21-100-1, which frames the design of fire detection installations, remains the technical reference to use even for a temporary installation, adapting it to the scale of the structure. In accommodation, office or storage modules, autonomous smoke detectors constitute the basic requirement; risk areas (technical, kitchen) justify automatic detection connected to an audible alarm throughout the structure. Using BOSEC-certified equipment is the quality benchmark to favour, even for temporary installation.
Who must request the emergency zone's advice and when?
The event organiser or main contractor of a construction site is the one who must request the advice of the competent emergency zone (hulpverleningszone) before installing a temporary structure accommodating the public or workers. This step must occur sufficiently early before opening to the public or the start of occupation, to allow the emergency zone time to process the file and, if necessary, impose additional arrangements (extra extinguishers, smoke vents, enhanced detection). The emergency zone then carries out the on-site inspection and issues its advice, which must be kept in the operator's file throughout the entire occupation period of the structure.
What are the temporary operator's responsibilities?
The temporary operator, whether event organiser or construction site project owner, bears the same responsibility for fire prevention as a permanent building operator, for the entire occupation duration. They must designate an identified person responsible for the structure's fire safety, often in connection with the company's prevention adviser, keep available the emergency zone's advice as well as the evacuation plan and posted instructions. When several parties work successively on the site (construction subcontractors, event technical service providers), each remains responsible for their installation perimeter, but the overall operator assumes overall coherence of the detection and alarm system, including maintaining it in working order.
How to ensure detection maintenance during the construction site or event duration?
Maintenance of a temporary detection installation follows the same principles as those set by standard NBN S21-100-2 for permanent installations, adapted to the actual lifespan of the system, which can range from a few days to several months. A functional check is necessary before commissioning the structure (alarm audibility, autonomous detector battery status), followed by regular inspections as long as occupation continues. At the end of operation, structure dismantling must be accompanied by formalised removal of the detection system, with traceability of inspections carried out throughout the usage period.