Fire Compartmentation across Surrey, London & the South East

Fire compartmentation divides a building into fire-resistant zones – each one designed to contain a fire long enough for occupants to evacuate and emergency services to respond.

It is a legal requirement under Building Regulations Approved Document B and a core obligation under the Regulatory Reform (Fire Safety) Order 2005.

It is also the element of passive fire protection most likely to be compromised by routine building works, refurbishments, and service installations – often without anyone noticing.

Surrey Fire & Safety carries out fire compartmentation surveys and remedial works for commercial, residential, and industrial buildings across Surrey, London, and the South East.

Fire Compartmentation Surveys

A fire compartmentation survey is a systematic, boundary-level inspection of every fire-rated element in a building – not just the visible ones .

A survey is typically commissioned following significant building works or refurbishment, as part of pre-acquisition due diligence, or where no previous survey exists. For full detail on what a survey covers, the report you receive, and how remedial works are carried out, see our compartmentation surveys page.

Key Elements of a Fire Compartmentation System

Every element of the building’s fire safety strategy exists to support it: fire doors maintain those boundaries at every opening, fire stopping seals them wherever services penetrate, cavity barriers protect them in the concealed voids where fire can travel unseen.

Passive fire protection services cover the full system – and compartmentation is its foundation.

The effect of a working compartmentation strategy shows up in national fire data: of all dwelling fires in England in the year ending March 2025, only 13% spread beyond the room of origin – the rest were contained to the room itself or the item first ignited.

Unsealed service penetrations and non-compliant fire doors are the two deficiencies found most often in compartmentation surveys – fire stopping and fire door inspections each have dedicated service pages.

Who Needs a Compartmentation Survey?

Any building with fire-rated boundaries has a legal obligation to keep them intact. The requirements and the risks vary by sector:

• Social housing and residential blocks — post-Grenfell legislation has tightened compartmentation obligations significantly, particularly around cavity barriers in external wall systems. See passive fire protection for social housing.
• Offices and commercial premises — fit-outs and IT infrastructure works are the most common source of breaches; new penetrations made and never sealed. See passive fire protection for offices.
• Care homes — high-risk occupancy and CQC compliance requirements mean compartmentation surveys are increasingly expected as standard. See passive fire protection for care homes.

Fire Compartmentation with Surrey Fire & Safety

• BAFE accredited and FIA affiliated – independently verified to recognised standards.
• Whole-building surveys – every fire-rated boundary assessed, not just the obvious elements.
• Clear, prioritised reports – photographic evidence and actionable recommendations, suitable for building control and audit.
• Full remediation capability – fire stopping, cavity barriers, fire doors, and boundary reinstatement all under one roof.
• 25+ years of experience across commercial, residential, and industrial buildings in Surrey, London, and the South East.

Fire Compartmentation – Frequently Asked Questions

What is fire compartmentation?

Fire compartmentation divides a building into fire-resistant zones using rated walls, floors, ceilings, doors, and seals. Each compartment contains a fire for a specified period –typically 30 to 120 minutes –giving occupants time to evacuate and emergency services time to respond. It works automatically, without requiring any activation, as part of the building’s passive fire protection strategy.

Is fire compartmentation a legal requirement?

Yes. Building Regulations Approved Document B requires compliant compartmentation in new and refurbished buildings. The Regulatory Reform (Fire Safety) Order 2005 requires responsible persons in non-domestic premises to maintain fire safety measures including compartmentation. The Fire Safety Act 2021 extended this to cover the building structure of multi-occupied residential buildings. Failure to comply can result in enforcement action, fines, or criminal liability.

What British Standards apply to fire compartmentation?

BS 9999:2017 provides recognised guidance on fire safety in building design and management, covering compartmentation strategies, performance standards, and maintenance requirements. BS EN 1366 governs fire resistance testing for service installations –directly relevant to fire stopping around penetrations in compartment boundaries. BS 476 (Parts 20 and 22) is the historical UK fire resistance test standard, still applicable to many existing installations in older buildings.

What is a fire compartmentation survey?

A systematic inspection of every fire-rated boundary in a building –walls, floors, doors, service penetrations, and concealed voids –to assess whether the compartmentation strategy is intact. It identifies breaches, missing fire stopping, damaged cavity barriers, and non-compliant fire doors, and produces a prioritised remediation schedule. Typically required following building works, pre-acquisition, or where no previous survey exists. See our compartmentation surveys page for full detail on what’s involved.

What are the most common fire compartmentation breaches?

Unsealed service penetrations –pipes, cables, and ducts passing through fire-rated walls or floors without fire stopping –are the most frequent finding. Other common defects include missing or damaged cavity barriers in roof and floor voids, fire doors with worn seals or non-functioning closers, and compartment boundaries breached by building works that were never properly reinstated.

What is the difference between fire separation and fire compartmentation?

Fire separation refers to an individual fire-resisting element –a single wall, floor, or door. Compartmentation is the overall system: all those elements combined to divide the building into protected zones. A building can have fire-rated walls and still have poor compartmentation if those walls have unsealed penetrations or non-compliant fire doors. Compartmentation is the whole; fire separation elements are its components.