Temporary structures

Temporary and abnormal structures

Temporary structures, such as stands, tents or stages, are often erected for public events. The temporary structures must be indicated in the event’s emergency plan.

An erection completion certificate must be drawn up for large or unusual structures. The certificate must be available at the venue. Temporary structures and constructions may also require a building permit or a planning permission for minor construction from the building control authority.

Considerations relating to tents

• Capacity must be calculated according to the same criteria as in assembly facilities.
• The tent canvas must be fire-resistant (SL1, DIN4102 B1 or equivalent).
• The tent must have at least two escape routes, the width of which is determined according to the same criteria as in an assembly facility.
• The escape routes of the tent must have signage. In small tents, signage can be handled using retro-reflective exit signs. Large tents (over 300 m²) must be equipped with illuminated exit signs with battery backup. If more than 30% of the wall surface of the tent is open, it can be classified as a canopy or an open structure, in which case the signs required are assessed on a case-by-case basis.
• The tent must be located at a sufficient distance from buildings. As a rule, single tents of less than 20 m² are placed at least 4 m from buildings. The distance between larger tents or tent groups and buildings must be at least 8 m.
• The placement of the tent must also take into account emergency access roads and escape routes of nearby buildings. Emergency access roads with a width of at least 3.5 metres must be reserved for the tent site.
• The tent must be set up according to the erection instructions.
• The tent must be secured to its base according to the manufacturer’s or a qualified designer’s instructions, for example with concrete or water weights.

In the absence of specific instructions or orders from the building control authority, and in the absence of instructions from the manufacturer or designer, it is recommended that tents of up to 300 m² be set up as follows.

• Connect the parts of the frame to each other with lockable connectors.
• The stability of the tent is affected by its structure, height and shape, among other factors. When using bulk weights, each corner of a small tent should have at least the following weights: 2 x 2 tents: 15 kg per leg, 4 x 4 tents: 62 kg per leg, 5 x 5 tents: 96 kg per leg and 6 x 6 tents: 139 kg per leg. The minimum weights apply to tents with tarp tops and to wind speeds of up to 15 metres per second (m/s). In case of stronger winds, the tarp top must be removed or more weights added.
• Tents must be secured to ground anchors or bulk weights with slings that have a tensile strength of at least 1,000 kg. Cords and equivalent are not acceptable fasteners.
• However, even tents secured in accordance with this guide might not remain secured in the event of a storm. In this case, follow the operating instructions specified in the emergency plan.
• In the event of a storm or winds of more than 15 m/s, secure tents more rigorously or discontinue their use. Guide people away from the tents and, if possible, take down the tents. If the manufacturer has issued other instructions, follow them.

Considerations relating to stages

• Follow the instructions of the stage manufacturer.
• Draw up an erection completion certificate.
• Use the stage according to the intended purpose defined by the manufacturer.
• Follow the weight limits of the stage structures.
• Be aware of the wind limits of the stage structures.
• The event organiser must plan operating procedures for various weather conditions.

Considerations relating to stands

• Stands must be built in accordance with the Ministry of the Environment Decree on the Operational Safety of Buildings (1007/2017).
• If there is a drop exceeding 0.5 metres or a risk of falling or stumbling, a guardrail must be built. Construct a guardrail in case of differences in levels of more than 0.7 metres in stands to which children have access.
• Secure seats to the base if the floor in the seating area is inclined or if there are differences in levels of floors between the rows of seats. Seats do not need to be secured to the base on a horizontal and level floor.
• If there are more than 60 chairs in the room and they are not placed around tables, secure them to each other in groups of at least four.
• Arrange fixed and connected seats into seating areas in rows with an adjacent passageway.
• The passageway of the seating area or standing room must be accessible from the end of each row.
• The required width of the passageway depends on the number of persons using it. The passageway for an assembly facility for a maximum of 60 persons must be at least 900 mm wide. The passageway in a space intended for more than 60 persons must be at least 1,200 mm wide.
• The clear width of the aisle between rows of seats must be proportional to the number of persons using the aisle, the type of seat and whether there is a passageway at both ends of the aisle or only at one end.
• The riser of the stairs to the stands must not exceed 160 mm in height and the run must be at least 300 mm deep.
• The clearance between any open-riser stairs to the stands must be blocked to prevent the passage of a cube more than 100 mm in width between the open-riser stairs.
• In a staircase or a ramp, a handrail must be installed along the entire length and dimensioned to provide a firm grip.
• Follow the erection instructions provided by the stand manufacturer.

Read more:

Capasity and evacuation arrangements