The power to classify buildings as earthquake risk has been available to local authorities since 1968. Through provisions in the Local Government Act, local authorities could require owners to strengthen or demolish buildings so classified. Authorities throughout New Zealand have progressively taken up these powers and many unreinforced masonry buildings have been demolished or strengthened. Relatively few owners have challenged the local authority's classification and it took until 1989 for a Council's ruling to be challenged in the District Court. During that year, three cases were heard, and the authors as members of a statutory panel of experts, were called upon to assist the judges. The experience provided a valuable, if long delayed, learning experience for the Courts, local authorities building owners and engineers. The Council's ruling was upheld in only one of the three cases. This paper describes each case and draws attention to some engineering and procedural aspects which contain lessons for those involved in future applications. The main lessons for engineers include the need for adequate preparation and presentation for the standard of proof required by the court.