The Owners - Strata Plan No 69312 v Rockdale City Council; Owners of SP 69312 v Allianz Aust Insurance

The Owners of Strata Plan No 69312 brought an action against Rockdale City Council and Allianz Australia Insurance seeking a declaration that the definition of "effective height" in the Building Code of Australia does not include the height of the basement storeys of a proposed building. The dispute arose because the Council had assessed the effective height of the building as being 25 metres, whereas the Owners argued it should be 26 metres. The case was heard in the Supreme Court of New South Wales.

The primary legal issues the court had to determine were the admissibility and relevance of expert evidence and the correct interpretation of the definition of "effective height" in the Building Code of Australia. The Owners sought to rely on the Guide to Building Code of Australia and the expert opinion of Mr Wynn-Jones, a building surveyor, to support their interpretation of the definition. The Council opposed the admission of the Guide and the expert opinion, arguing that they were not relevant to the question of interpretation and that Mr Wynn-Jones' opinion extended beyond the scope of the definition to include an assessment of the Council's conduct.

The court found that the Guide to Building Code of Australia was not admissible because it was not relevant to the interpretation of the definition of "effective height". The court also excluded the expert opinion of Mr Wynn-Jones, except for his descriptive explanations of the plans of the proposed building and his identification of a particular stairway. The court held that Mr Wynn-Jones' opinion on the meaning and application of the definition was not admissible because it extended beyond the scope of the definition and included an assessment of the Council's conduct. The court held that the correct interpretation of the definition of "effective height" did not include the height of the basement storeys of the proposed building.

The court ordered that the Owners' claim for a declaration that the definition of "effective height" did not include the height of the basement storeys of the proposed building was to be dismissed. The court also ordered that the Owners pay the costs of the proceeding.