In the construction industry in Australia, it is not uncommon to refer to the Guide to the Building Code of Australia (the Guide) to help interpret the meaning of provisions in the Building Code of Australia (BCA).

Recent Supreme Court decisions in New South Wales and Victoria which have held that the Guide on its own has no legal authority, however, underscore the need for caution in this regard, and have shown that Courts will interpret BCA provisions on the actual text of the provision rather than the Guide’s interpretation of that provision.

The first such case, The Owners – Strata Plan No 69312 v Rockdale City Council in the New South Wales Supreme Court, concerned the interpretation of the meaning of effective height as defined in the BCA.

The BCA defined effective height as “the height to the floor of the topmost storey (excluding the topmost storey if it contains only heating, ventilating, lift or other equipment, water tanks or similar service units) from the floor of the lowest storey providing direct egress to a road or open space.”

The guide to the BCA provided:

“Effective height measures the height of a building for safety purposes. Effective height is measured from the lowest storey providing direct egress to a road or open space (this will usually be the level at which the fire brigade would enter) – to the floor of the top storey. Plan rooms and spaces at the top of the building used for maintenance purposes are not included in effective height.”

The defendants submitted that effective height should thus be measured from the storey at which fire fighters would most likely enter the building – in this case, the pedestrian entrance. On a plain interpretation of the BCA provision (without reference to the Guide), however, the Court ruled that the lower floor car parking storey was the lowest storey that provided direct egress to a road or open space.

In his judgment, The Honorable Justice Geoff Lindsay found that whereas the Building Code itself was specifically referred to in Acts and Regulations, the Guide was not. Furthermore, not only did the Guide fail to add anything material to the BCA definition of effective height, it was merely ‘gloss on the language of the BCA’ in this respect.

“The Guide adds nothing material to the language of the text of the BCA under consideration or, if it does … that addition is a gloss on the language of the BCA. The introductory paragraphs of the Guide expressly disclaim any pretence of the Guide rising higher than the text of the BCA,” Lindsay wrote in his judgment.

Lindsay is not alone in treating the Guide in this manner. In last year’s Salter v Building Appeals Board & Ors case in Victoria, for example, Supreme Court Justice David Beach noted it would be wrong to allow any ancillary document – including the Guide – to in any way alter the proper construction and application of the Code as it is written.

Indeed, amongst legal practitioners, wariness about use of the Guide as a complete authority in interpreting the BCA is growing. One senior construction lawyer recently lamented that he would exercise ‘great caution’ in using the guide to help interpret the BCA because ‘absent it having any force of law, its use as an interpretation instrument is potentially problematic.’

All of this points to a critical fact: the Guide is simply that – a guide, a companion to the BCA which should be read in conjunction with the Code and cannot change or alter the BCA nor give any of its provisions a meaning different to its plain English meaning. As stated in its introduction, the Guide has no regulatory force and the Australian Building Codes Board accepts no responsibility for its contents.

In light of this, builders should exercise extreme caution in using it as an interpretation instrument of the BCA.