When Do Existing Buildings Need a Fire Strategy?

Many people assume that fire strategies are only required for new buildings. In fact, a significant and growing proportion of fire strategy instructions relate to existing buildings — those undergoing refurbishment, change of use, or registration under the Building Safety Act 2022. Understanding when an existing building requires a fire strategy, and what that fire strategy must contain, is important for building owners, managing agents and architects working with the existing stock.

Refurbishment Works

A fire strategy is required for refurbishment works that affect the fire safety of an existing building. This includes:

• Alterations to escape routes — changing the layout of corridors, adding or removing doors, or modifying stairwells
• Changes to compartmentation — adding or removing partition walls, creating openings in compartment walls or floors
• Change of use — converting offices to residential, houses to HMOs, or any change that alters the occupancy characteristics of the building
• Extension — adding floor area to an existing building, particularly where the extension connects to or affects the existing means of escape
• Works that affect the external wall — re-cladding, adding insulation to the facade, or changing balcony construction

Building Safety Act Registration

Existing higher-risk buildings registering with the Building Safety Regulator require a building safety case, which must include a fire and structural safety assessment. For buildings without a fire strategy on record, this requires a retrospective fire strategy to be produced — an assessment of the building as it exists, identifying gaps and recommending remediation.

How Fire Strategies for Existing Buildings Differ from New Build

A fire strategy for an existing building must work with what exists rather than designing from scratch. The fire engineer must inspect the building, gather as-built information, understand the existing means of escape and compartmentation, and assess how the existing building performs against current standards. Where it falls short, the fire strategy identifies the gaps and recommends remedial works.

Crucially, existing buildings are not required to comply with current building regulations — they must be demonstrably safe. This principle of "reasonable practicability" means that the fire strategy for an existing building can take a proportionate approach, recognising that some non-compliances with current standards may be acceptable where the overall level of safety is adequate.

Information Gathering for Existing Building Fire Strategies

One of the main challenges of fire strategies for existing buildings is information — as-built drawings are often missing or inaccurate, materials are unknown, and the history of alterations to the building may be poorly documented. Fire Safety Services uses a structured information gathering process for existing building fire strategies, including a site survey to confirm building dimensions and configuration, material identification, and assessment of existing fire safety systems.