An open-plan layout is where almost the whole floor area of a storey consists of one open space minimally sub-divided into smaller rooms.

General considerations

Open storey planning, or open-plan layout, is an arrangement in which the majority of the floor area of a storey consists of an open space which is not divided by walls. However, the presence of screens or furniture may produce a pseudo-cellular layout, and an open-plan space may include some cellular rooms if it is desirable to the occupant to separate certain functions e.g. meeting rooms and refreshments. Cellular rooms within an open-plan space are likely to be separated from the larger space by lightweight partition walls rather than more heavyweight construction which would be more commonly found in a fully cellular layout.

It would be expected that all aspects of a building that are required to be fire resisting, such as protected escape stairs, would be enclosed within fire resisting construction.

Inherent benefits

  • Firefighters may be able to see across an entire open-plan space without walls obstructing their vision.
  • Occupants are more likely to be aware of fire or smoke at an early stage in an open-plan layout compared to a cellular layout, and therefore are less likely to become trapped and require rescue.

Inherent hazards

  • An open-plan space is likely to contain a larger fire load within the space when compared to a cellular layout but will allow wider fire and smoke spread than a space which is sub-divided into rooms
  • Fire may affect a greater proportion of the space
  • The potential for rapid fire development is greater in open planned space and greater resources may be required than for a similar incident in a cellular building
  • If the occupants of an open-plan space change the layout or use of that space, previous familiarisation visits may become misleading

Further information

BS 9999:2017 - Code of practice for fire safety in the design, management and use of buildings

Telstar House (London Fire Brigade, 2003)