When As-Built Information Is Missing: A Risk-Led Investigation Approach

Missing or incomplete as-built information is common, particularly for older assets, modified structures, or facilities with multiple historic interventions. The key is not to guess, but to manage uncertainty in a controlled way so decisions remain safe, proportionate, and auditable.

Principles of a risk-led approach

• Start with what is known and verify the critical assumptions first

• Use staged investigation, with hold points before any high-risk action

• Combine non-destructive methods with controlled opening-up where necessary

• Keep the scope tightly linked to the decision that must be made (for example, “is it safe to remain in service?”, “what repair is required?”, “what strengthening is needed?”)

Controls that reduce risk
A practical approach often includes:

• Pre-inspection review of any available information, even if partial

• Close visual inspections to identify likely structural form and load paths

• Targeted scanning and mapping where intrusive work is planned

• Stop-work triggers if unexpected details are encountered

• Clear reporting that distinguishes confirmed facts from assumptions

Why this matters
Investigation is not just about finding defects. It is about gathering enough evidence to choose the right action, justify expenditure, and avoid rework. A structured method reduces programme risk and improves repair buildability because the contractor receives clearer design intent and better-defined quantities.