Ceiling voids (including suspended ceilings) and raised floors are essential parts of a building for the running of building services, spaces for electrical and data cabling, control equipment and cabinets. These areas are deemed as concealed spaces in a built environment because they are often isolated, unoccupied or obstructed from the sight of view. Concealed spaces can be found not only in almost all large built industrial environments but also in shopping malls, transportation hubs, exhibition centres and tall residential and commercial buildings. When these spaces are also used as air plenum to form a part of building HVAC air circulation, air velocity inside these concealed spaces can be extremely high, particularly for cleanrooms and data centres.

If a fire, originating from a concealed space, is detected too late or encountered with inadequate response measures, the resulting damage can be substantial. In addition to the damage as such, a fire is likely to jeopardise business continuity for mission critical infrastructure like IT or telecom operation