How Many Emergency Exits Do I Need?

Number of Exits by Occupancy

• Up to 60 persons: 1 exit (minimum 750mm wide)
• 60–600 persons: 2 exits (each minimum 850mm)
• 600–1,000 persons: 3 exits
• Over 1,000 persons: 4+ exits

Maximum Travel Distances (Approved Document B)

• One direction only (dead end):
  • Low risk (offices): 18m
  • Normal risk (shops): 18m
  • High risk (industrial): 12m
• More than one direction (alternative exits):
  • Low risk: 45m
  • Normal risk: 45m
  • High risk: 25m

Exit Width Calculation

The minimum aggregate width of exits is based on occupancy capacity:

• 80 persons per 520mm (ground floor level exit)
• 60 persons per 520mm (exits via stairs)
• Minimum single exit door: 750mm clear width
• Minimum when two or more exits: 850mm clear width each

Key Principles

• Exits must be independent — fire blocking one must not affect others
• Alternative exits should be at least 45° apart when measured from any point
• Exit doors must open in the direction of escape
• Final exit must lead to a place of safety (open air at ground level)
• Emergency lighting required on all escape routes

Important Note

These are general guidelines based on Approved Document B (fire safety). The actual requirements depend on the specific building use, layout, fire risk assessment, and local authority requirements. Always consult Building Control or a qualified fire engineer for specific projects.