What does a proportionate and risk-based safety case look like?

A proportionate and risk-based safety case concentrates effort on the things that matter most to the safety of the particular building.

It starts with the building and its reasonably foreseeable risks rather than attempting to demonstrate compliance with every possible standard or produce the largest possible collection of documents.

A risk-based approach asks:

- What could go wrong? - What could cause it to happen? - What would the consequences be? - What measures are relied upon to prevent it? - What measures would limit the consequences if it happened? - How do we know those measures are effective?

The depth of assessment and evidence should reflect the significance and uncertainty of the risk.

For example, an important control preventing a potentially severe fire or structural consequence should generally receive greater scrutiny than an administrative issue with little influence on the building safety risk.

A proportionate safety case can also acknowledge uncertainty. Older buildings in particular may not have complete records or evidence demonstrating precisely how every element was constructed.

The absence of perfect information does not automatically mean that every conceivable investigation is reasonable. The safety case should explain what is known, what remains uncertain, why that uncertainty matters and whether further investigation or additional risk reduction measures are reasonably required.

Proportionality does not mean doing less. It means directing attention, evidence and resources towards the things that make the greatest difference to understanding and managing building safety risk.