Home / Physical factors / Structures, installations and inspections / Overlay OverlayOverlay relates to temporary installations used for a specific event. Overlay is the term used to describe the use of temporary installations (such as ‘fan zones’, seating decks, tents, kiosks, bridges and generators) for specific events. It can also include the provision of new roads or routes. Some of these installations may be built to the same specifications as permanent installations and may even, in time, become permanent. But whether temporary or permanent, it is important that management should consider the effects of overlay on existing circulation routes, and therefore also on operational plans and even on the safe capacity of the ground. Examples of where overlay may impact upon circulation routes include the provision of: spectator accommodation in areas not normally used by spectators, for example on the pitch or area of activity additional access routes for the delivery of equipment, such as staging, sound systems and media installations additional facilities required to accommodate a greater number of spectators, or spectators of a different profile, or for events of a longer duration than the norm; such facilities to include temporary turnstiles, portable toilets, food and drink outlets, hospitality tents, information points and first aid facilities additional facilities required to support commercial activities, such as merchandising outlets and stadium dressing additional security and counter terrorism measures (see Section 3.19). In all cases, the overlay should not compromise any means of ingress, egress, accessibility or general circulation, or result in adverse changes to the known and usual speed or direction of crowd flows. Where this cannot be achieved and appropriate mitigation measures cannot be put in place, the capacity for the event is likely to be reduced. It is therefore essential that from an early stage of planning, the ground’s safety management team works closely with those designing the overlay to ensure that any potential safety issues are identified and resolved. The design of any overlay should be circulated to all parties for agreement in advance.