Inspection by Approved Inspectors

In NHBC Building Control Services Ltd v Sandwell Borough Council (1990) stated that the regulations do not require detailed inspections of all parts of the building, but random sampling is satisfactory.
"Any system of inspection that is selective involves consideration not only of the importance of a risk against which the inspection is designed to guard, but of the likelyhood of it's occurrence."
"The mere fact that an important defect escaped detection in a particular instance cannot …. consistute a proper basis for concluding beyond reasonable doubt that there was any failure to undertake the functions of supervision so as to render false the statement that the (inspector) has performed those functions."
Note
The Approved Inspector can arrange for plans or work to be inspected by or on his behalf by someone else (although only the Approved Inspector can give Plan or Final Certificates). Delegation does not affect the liability.
The Building Act states that "an Approved Inspector is liable for negligence on the part of a person carrying out an inspection …… as if it were negligence by a servant of his acting in the course of his employment"