The Cost of Late Fire Safety Input

In our experience working across thousands of building projects, one pattern emerges consistently: the later fire safety is considered in the design process, the more expensive the consequences. Projects that appoint a fire engineer at RIBA Stage 1 or 2 almost never face significant fire safety-related redesigns. Projects that commission a fire strategy for the first time at building control stage very often do.

Why Fire Safety Shapes Building Design

Fire safety is not a finish — it is embedded in the fundamental structure of a building. The layout of escape stairs, the position of fire compartment walls, the specification of the structural frame, the design of the facade, the routing of services — all of these are influenced by fire engineering requirements. Changing any of them at a late stage in the design process is disruptive and expensive.

An escape stair in the wrong position may not achieve the travel distance requirements. A compartment wall missing from the design may require structural alterations to add. A facade system that contains combustible materials may require complete replacement. A structural frame that provides inadequate fire resistance may need expensive passive fire protection. All of these problems are trivially easy to avoid if a fire engineer is involved from the start.

The Gateway 2 Problem

The Building Safety Act 2022's Gateway 2 requirement makes early fire engineering involvement even more important for higher-risk buildings. Gateway 2 requires the Building Safety Regulator to approve the building's design before construction begins. If significant fire engineering issues are identified at Gateway 2 — because fire safety was not properly addressed during design — the programme delay while the design is revised and resubmitted can be substantial.

Real Costs of Late Fire Safety Input

• Redesign of escape stair configuration at technical design stage: weeks of delay and potentially significant structural cost
• Rejection at building control due to inadequate fire strategy: typically 4 to 8 weeks of delay and significant consultant fees
• Gateway 2 rejection requiring design revisions: 12 to 20 weeks or more added to the programme
• Fire strategy issues identified during construction: potentially months of delay and six-figure remediation costs

What Early Fire Engineering Looks Like

Early fire engineering input does not mean a full fire strategy at RIBA Stage 1. It means a fire engineer reviewing the concept scheme and providing clear, concise advice on the fire safety constraints and opportunities — the escape route options, the compartmentation strategy, the facade requirements, the structural fire protection implications. This can often be provided at a fixed fee for a few hours of a chartered fire engineer's time, and it is among the highest-value investments a developer can make.