(1) If the local authority, after a full and proper investigation, has reasonable grounds to believe that-

a) any building or sewerage work has been undertaken otherwise than in accordance with approved plans; and

b) the failure to comply with the plans might result in the building or any part thereof being unstable or in any way dangerous, or the sewerage system being in any way unsatisfactory;

and if the work on the building or sewerage system has progressed so far that it is impossible to ascertain whether or not the plans have been properly followed, the local authority may, by written notice, order the builder or plumber to cause the portion of the work concerned to be cut into, laid open or demolished for investigation to such an extent as may be specified in the notice.

(2) The notice referred to in subsection (1) may specify the time within which such work shall be undertaken.

(3) Where any work is to be cut into, laid into open, or demolished for investigation in accordance with an order served in terms of subsection(1), no person shall carry out further work on such building or sewerage system if such further work is to be supported by the work which is to be tested.