ExoSett design

Fire safety

Fire safety is a fundamental building-design responsibility. ExoSett does not make a building fireproof, and the accommodation frame cannot provide a complete fire strategy by itself.

An ExoSett building should use a layered fire-safety approach involving the accommodation cassettes, accommodation frame, service frame, façades, access routes and building services.

The appropriate strategy will be project-specific. The principles and possible measures described here are design considerations and options, not a finished ExoSett fire-safety product, and ExoSett does not itself guarantee regulatory compliance.

Building-wide responsibility

A layered fire-safety approach

The detailed strategy will depend on the building’s height, use, layout, location and regulatory requirements, but should address the following principles:

  • Reduce foreseeable sources of ignition.
  • Detect fire and warn occupants promptly.
  • Control fire and smoke near their source.
  • Protect escape routes and areas of relative safety.
  • Maintain structural stability for the required period.
  • Prevent rapid and disproportionate spread between cassettes, cells, storeys and other parts of the building.
  • Provide suitable access, information and facilities for firefighters.
  • Support inspection, maintenance and safe recovery after a fire.

Components and interfaces

Cassettes and frame both contribute

Accommodation cassettes are expected to make a significant contribution. Depending on their use, this may include fire-resisting construction, controlled internal materials, detection, suppression, protected service penetrations and suitable doors and ventilation interfaces.

The accommodation frame also has an important role. Spaces around cassettes must not become uncontrolled routes through which smoke or flame can spread across the building. Possible measures may include:

  • fire and smoke barriers within the frame;
  • division of the frame into controlled fire or smoke zones;
  • flexible or intumescent barriers around installed cassettes;
  • protected service connections and penetrations;
  • fire-safe arrangements for vacant cells;
  • smoke extraction or ventilation through defined routes;
  • fire protection for structural members and connections.

Engineered strategy

Manage fire and smoke across the building

Completely sealing every space is not necessarily the correct answer. Some buildings require controlled ventilation or smoke extraction. The essential requirement is that airflow, smoke movement and fire spread are understood and managed as part of an engineered building-wide fire strategy.

Every permitted configuration of an ExoSett building—including occupied cells, vacant cells and cassette replacement—must maintain the level of fire safety required by the building design.

The illustrative Fire story explores how replaceable accommodation cassettes could support recovery after a building fire. It illustrates a possibility rather than providing technical guidance.