15 The first question is whether it is cl B6.1 or cl B6.2 which is the relevant clause of the DCP applying to the proposed development.
16 It seems that the commissioner was misled by the headings to each clause. The heading to cl B6.1 is "Access Driveways - Residential Development up to 2 dwellings (single dwelling and dual occupancy)". The heading to cl B6.2 is "Access Driveways - all development other than up to two dwellings". The headings to these provisions are not, however, taken to be part of the instrument: s 35(2) of the Interpretation Act 1987. The development to which each control applies is set out in the body of each clause. Clause B6.1 applies to new dwellings and additions, to an attached dual occupancy, and to a detached dual occupancy. It does not apply to land subdivision. Clause B6.2 applies expressly to land subdivision (inter alia). Each clause fixed a different maximum gradient for access driveways and, as noted above, only cl B6.1 allows a variation to the maximum gradient.
17 It follows that by ignoring the heading to each clause and looking at the development expressly listed under each clause, it is cl B6.2 which is the relevant control in the present case. It is that clause which becomes the fundamental element in or the focal point of the decision making process. The commissioner, however, held at par [11] of his decision:
In the circumstances I have decided that B6.1 is relevantly applicable and that subject to a merit assessment, a gradient up to 33 % can be acceptable.
18 The obligation to take into consideration the DCP as a fundamental element in or a focal point of the decision-making process includes an obligation to take into consideration the applicable control in the DCP.
19 In failing to take as the basis for his determination the relevant control and by adopting instead as the basis for his determination a different (and more lenient) control the commissioner erred in law. That is, there cannot have been "a proper, genuine or realistic consideration of the provisions of the DCP" if, as here, the commissioner relied upon a different and more lenient control than that which was directly applicable.
20 It might be said that the commissioner made a finding of fact which is not open to review. However, as Glass JA said in Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 at 156:
A finding of fact in the Commission may nevertheless reveal an error of law where it appears that the trial judge has misdirected himself ie has defined otherwise than in accordance with law the question of fact which he has to answer.
21 In the present case the commissioner misdirected himself by defining cl B6.1 as the relevant control and assessing the development against that control rather than the applicable control.
22 Of course, a development control plan is not an environmental planning instrument and the determining authority may depart from its provisions, but only after giving proper, genuine and realistic consideration to its relevant provisions: Zhang at 602 [74]. Then, having done so, the determining authority may decide whether other factors under s 79C of the Environmental Planning and Assessment Act 1979 justify a variation from the standard in the DCP: Ai v Newcastle City Council (2003) 126 LGERA 194 at 210 [62]. But here, the commissioner used as the basis for his consideration the wrong control in the DCP and in doing so he misdirected himself.
23 I thus accept the submission of Mr D T Miller for the council that there cannot have been real consideration of the relevant provision if, as here, the commissioner substituted for the specified provision a different approach founded on the application of an inappropriate and more lenient control. That is, the commissioner substituted for the statutory requirement a different approach. As Spigelman CJ said in Zhang at 602-603 [76], this approach could only be supported if the discretion was entirely at large, that is, that there were no "standards" of any character which the decision maker had to take into account.
24 The misconstruction of a relevant provision will always be an error of law: Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 at 156-157. The commissioner's holding that cl B6.1 was relevantly applicable clause and not cl B6.2 amounts to an error of law. The appeal must be upheld.