What happened

A side extension's foundation depth was specified at 1.8m near a mature oak. The trench was excavated to 1.2m, the bearing was misjudged, and concrete was poured.

How it was discovered

Building Control inspection the following day. Records showed the design depth, the photographs of the trench did not.

The consequences

Foundation excavated out, reformed to depth, re-poured. Two weeks delay, a five-figure cost, and a difficult conversation between the builder and the homeowner.

What homeowners can learn

Foundations must be inspected before pour, not after. The inspection costs nothing compared to the redo.