In Chugg v Pacific Dunlop Ltd ... there is ... a clear dictum (at 260) in the reasons for decision of Dawson, Toohey and Gaudron JJ that 'overmuch significance' ought not to be given to 'the relative knowledge of an employer or an informant', because in many instances the questions of practicability do not involve special knowledge. Insofar as the reasons of Dawson, Toohey and Gaudron JJ adopted (at 262), with approval, the observations of Lord Upjohn in Nimmo v Alexander Cowan & Sons Ltd [1968] AC 107, 125 - 126, it is also apparent that the duty, resting upon the employer or other person obliged to exercise care, is 'with his experts to consider the state of the place of work in all its circumstances and to take whatever steps he could, so far as reasonably practicable, to make it safe'.
Far from limiting the objective state of knowledge to the subjective state of knowledge of the particular builder (in the present case) or persons in comparable positions, the legislation, in my view, casts an obligation upon all persons, upon whom comparable duties are imposed, to acquaint themselves with practicable measures existing in the industry for the maintenance of safety and the avoidance of hazard. They will not be excused from a failure to perform this obligation simply because of the limits of their own subjective knowledge, except on occasions where, as Steytler J said in Hamersley Iron Pty Ltd v Robertson (Unreported, WASC, Library No 980573, 2 October 1998), it is knowledge of a special kind attributable to a specialised contractor and outside the scope of the knowledge to be expected of a builder. I must say, with all respect, that I have hesitations in limiting the scope of practicability even to that extent, because the definition of 'practicable' within s 3 of the Act speaks about 'state of knowledge' in the broad, without limiting the state of knowledge to any particular trade, profession or occupational experience. This is consistent with the policy of the Act which, in my view, is intended to achieve a situation that if, objectively speaking, there is known within an industry that there are hazards of a particular kind which may be injurious to the health and welfare of persons on worksites, and that there are means available of avoiding or reducing those hazards, then, having regard to factors such as the degree of risk, the means of removing or mitigating the risk and the availability, suitability and the cost of the means to reduce the risk, the decision about practicability will then be taken in a balanced and objective fashion.
The crucial point of this statutory language, however, is that it lends no support at all to a view of practicability which is associated with a limited knowledge by some person within the industry who, by hypothesis, is oblivious to the existence of objective knowledge within the industry which identifies the risk and suggests means of addressing it. Certainly, there is a balancing judgment to be made, having regard to the degree of risk involved, the means available of reducing the risk and the associated costs, but that balancing exercise needs to be performed once it is established that there is an objective state of knowledge within the industry which exposes the hazard and suggests a means of coping with it. That state of knowledge is not limited to occasions when the risk is known and appreciated at lower levels, or by the individual on whom the duty is cast.
As framed, the obligation requires persons on whom such duties are cast to acquaint themselves with the objective state of knowledge within the industry and, as implied by Lord Upjohn in his remarks in Nimmo v Alexander Cowan & Sons Ltd, to take advice from experts and others to supplement his or her own appreciation of the situation. Failure to do that does not displace the existence of an objective state of knowledge or excuse a failure to perform the duty if, otherwise, it were practicable to perform it. This is, if I may say so with respect, the essential error which pervades this aspect of the decision at first instance; namely, to associate the objective state of knowledge with the scope of knowledge actually possessed or to be expected of such a builder. In my view, that significantly understates the extent of the statutory and regulatory duties here under consideration. In Hamersley Iron Pty Ltd v Robertson, Steytler J expressly contemplated that in relation to a personal duty to provide a safe workplace, so far as is practicable, that latter phrase determines the extent of the obligation: