Understand your Risks!

What should the first step be when you’re developing the safety case for a higher-risk building (HRB)?

You should first identify and manage your HRB risks. Part 4 of the BSA 22 (paragraph 62) defines the building safety risks as:

1.       The spread of fire.
2.       Structural failure.

I like to break up the ‘spread of fire’ into ‘fire in a compartmentation’ and ‘fire in a communal area’. The risk workshop should not only identify what could cause a fire within the compartmentation or communal area, but also how the risk is managed in your safety case.

With a clear understanding of the risk and how it is being managed, the Hazard Risk Matrix (HRM) can be used to identify the severity and likelihood of the event. If the risk remains ‘Very High’, for example, then further mitigations will be required to reduce the risk level – if this cannot be done, you may ultimately have to decant the HRB until an engineering fix is achieved.

The design of your HRM is also very important. I find that a 3x3 HRM does not offer the required fidelity to assess the risk, so prefer to use a 5x5 HRM. You then need to define the organisation’s definitions of risk probabilities and severities – again, this must be done carefully with all stakeholders.

Do you think that the BSA 22 should go one step further and asked HRB Principal Accountable Persons to identify all building risks and not just focus on fire and structure?