SCDF Fire Code 2023 Decision Workflows

Buildings (other than PG I) must be divided into compartments by compartment walls and floors when storey floor areas or cubical extents exceed Table 3.2A limits. Compartments are limited by storey height (24 m threshold) and must not comprise more than 3 storeys below 24 m or more than 1 storey above 24 m or below ground. Buildings with a sprinkler system complying with Chapter 6 may be exempt from size-based compartmentation, subject to other conditions.

All elements of structure must be constructed of non-combustible materials and achieve the minimum fire resistance periods specified in Table 3.3A, which varies by purpose group, building height, floor area, and cubical extent. Performance is assessed under BS 476: Part 20–23 (stability, integrity, insulation) or by the notional periods in Annex 3A. Certain exemptions apply to single-storey buildings, non-load-bearing external walls, and open-sided car parks.

External walls within 1 m of the relevant boundary, or exceeding 15 m in height, must be constructed of non-combustible materials and attain the required fire resistance. Unprotected areas (openings and combustible cladding) in external walls are limited by distance from the relevant boundary per Annex 3B; sprinkler-protected buildings may double the unprotected area or halve the required boundary distance. Separating walls between adjoining buildings must be solid, continuous full-height barriers of non-combustible construction with no openings except fire-rated doors or pipes.

Protected shafts (staircase, lift, service shafts) must form complete fire barriers between compartments and be constructed of non-combustible materials with the appropriate fire resistance. Openings in protected shafts, compartment walls, and separating walls must be protected by fire-rated doors, intumescent pipe collars, fire dampers, or appropriate enclosures. Exit staircases must be fully compartmented with non-combustible construction, and doors into staircases must have at least ½-hr fire resistance.

Concealed spaces (suspended ceilings, raised floors, roof cavities) must be subdivided by cavity barriers to prevent undetected spread of fire and smoke. Cavity barriers must provide at least ½-hr fire resistance and must be continuous at compartment wall/floor junctions. Maximum cavity dimensions are regulated by Table 3.11A (20 m between roof and ceiling for most PGs; 8 m for other cavities with non-Class 0 surfaces). All gaps around penetrations in compartment elements must be fire-stopped with tested materials.

Surfaces of walls and ceilings must meet minimum flame-spread classifications from Table 3.13A (Class 0 / EN Class B for most lobbies/staircases; Class 1 / EN Class C for rooms in PG III–VIII; more relaxed for sprinkler-protected buildings). Roof coverings must achieve at least Class 1 flame spread (or ASTM Class A) except for PG I/II and sprinkler-protected buildings. Construction materials including composite panels, plastics, intumescent paint, fire-rated glass, and UPVC window frames must comply with specific material standards in Cl.3.15.

Chapter 3 has three primary objectives: (1) minimise the risk of fire spreading between adjoining buildings through separation; (2) prevent untimely building collapse by requiring stable and durable construction; and (3) prevent fire spreading within a building by dividing it into compartments. These objectives are achieved through the full chapter's provisions.