Planning Gateway One - Performance-based designs

Government guidance on compliance with the functional requirements of the building regulations allows designers to follow fire safety standards and guidance (such as Approved Document B or British Standard 9991) or a performance-based design.

HSE's approach to performance-based design is consistent with its approach to safety engineering when regulating the wider health and safety industry. HSE's decision making process is explained in the guidance document, “Reducing risks, protecting people: HSE’s decision making process”. The guidance promotes “inherently safer design” and states:

“Adoption of the principles of inherently safer design is particularly important where the consequences of plant or system failure are high. HSE will press for the incorporation of inherently safer design features, where these are possible, to reduce the reliance on engineered safety systems or operational procedures, to control risk.”

This approach is consistent with the “Principles of Prevention” embedded in health and safety legislation, such as the Management of Health and Safety at Work Regulations 1999, and other laws such as the Regulatory Reform (Fire Safety) Order 2005.

Accordingly, when assessing performance-based designs, HSE will consider whether hazards have been avoided through inherent design. This is particularly relevant at the planning stage when matters such as the form, layout, appearance, access arrangements and massing of a development are being considered. Where there are reasons why a hazard cannot be avoided, HSE will consider the suitability of mitigating the associated risks with active systems or management procedures. In that context, a competent fire engineer’s role as part of the design team, working with architects and other design professionals from the inception of the project, is critical. 

It is useful for HSE to understand the design rationale for a development when considering how a performance-based design has evolved through the design process. For example, reasons for relying on a performance-based design, in whole or in part, might include:

• site constraints e.g.  environmental designations, heritage designations or physical features such as surrounding infrastructure and sensitive neighbouring uses,
• making the best use of land and maximising the number of dwellings,
• challenges related to refurbishing existing buildings, and
• the promotion of a genuinely novel design.

In practice, the rationale for a fire safety design may include a number of these factors and how they interact with each other. The value to HSE of having a clear understanding of the rationale for the fire safety design is to have confidence that fire safety matters have been considered from the start and the applicant’s approach to the development has been reflective and transparent. In this way, the outcome of the design process at the planning stage is a holistic approach tailored to the needs of the development, rather than taking a minimalist approach to fire safety at the planning stage.

In the context of considering a performance-based design, over reliance on building management processes and procedures is likely to be identified as a concern and HSE will regard this as unsustainable and unreliable over the lifetime of a building, particularly in new developments. Designers should work to reduce management burdens and costs on future owners, occupiers, and regulators.

If a performance-based design is used for all or part of the development, then this should be identified in section 6 of the fire statement form using the drop-down list to identify the design standard as “BS7974” or “fire engineered approach” for the development, building or building element. Sections 7 and 8 of the fire statement form provide space to specify and explain the actual standard used and provide cross references to more detailed explanatory text in other application documents, if needed.