Orderly, proper and sound urban planning: WA Supreme Court upholds SAT decision adopting a conservative approach to noise modelling of child care centres in residential areas

01 November 2022

The Western Australian Supreme Court, in Sharon Property Pty Ltd v The Presiding Member of the Inner-North Joint Development Assessment Panel [2022] WASC 332, has recently affirmed a decision by the State Administrative Tribunal (Tribunal) to refuse a development approval for a childcare centre in Swanbourne. Specifically, finding no error of law in the Tribunal’s reasons.

The proposal was for a child care centre catering up to 90 children from a two storey purpose built facility on the corner of a major road carrying 11,647 vehicles per day and a tree-lined residential cul-de-sac with a very distinct residential character.

This case involved the interface of the separate environmental and planning jurisdictions, specifically a planning decision for which statutory environmental noise criteria provided guidance.

The appeal involved modelled predicted (not actual) noise emissions based on the assigned noise levels of the Environmental Protection (Noise) Regulations 1997 (WA) (Environmental Noise Regulations). One expert relied upon a proprietary or bespoke methodology that had been utilised for 15 years. Whereas another referenced the Association of Australian Acoustical Consultants’ Guideline for Child Care Centre Acoustic Assessment (Acoustic Guideline).

The Tribunal commented that it did not regard the modelling assumptions to be conservative and that:

“In the context where the Proposed Development is to be located on residential land and in almost a purely residential locality, we would ordinarily expect a more conservative set of assumptions to have been established”.

The contest of experts

The Tribunal preferred the conclusions of one expert over the other, which, as the Supreme Court noted, does not give rise to an appealable question of law. It was contended, before the Supreme Court, that the Tribunal failed to examine and consider relevant expert evidence in reaching its decision – that the substantive debate reflected in the expert evidence was not dealt with by the Tribunal. Specifically, that there was an error in the fact-finding process or methodology (rather than the actual fact finding itself).

The Supreme Court held that:

  • the Tribunal was “exercising a statutory discretion by reaching an evaluative, largely factual determination.” Specifically, to reach “the correct and preferable decision in respect of the impact of the Development on the amenity of the locality”, where the amenity finding based on forecast noise emissions is a matter of fact;
  • the entire or sole basis of the Tribunal’s preference for the evidence of one expert over another was not consistency with the Acoustic Guidelines. Rather, the expert evidence that relied upon the Acoustic Guidelines reflected the more conservative approach that was required by the character of the locality and the sound power level assumptions were “more reasonable and accurate”;
  • while the Tribunal’s reasons might have more specifically expressed why one expert option was preferred, the “the Tribunal’s statutory role and function [did not require it] to descend to that level of reasoning in its evaluation and analysis”, which the Supreme Court considered were largely implicit in the reasons given; and
  • whether “some aspect of the evidence or submissions should have been granted more prominence in the Tribunal’s reasoning than they received, is a matter of degree and emphasis. It is not a basis for appeal on a point of law”.

It was also contended before the Supreme Court that the Tribunal did not consider or properly understand that the noise emitted from the development would be community noise. The appellant contended that if the noise amounted to community noise that it would be reasonable under the Environmental Noise Regulations.

The Supreme Court addressed the interface of two regulatory regimes, being the environmental context under the Environmental Protection Act 1986 (WA) and the mandatory planning considerations under local planning scheme “deemed provisions”. It concluded that in any case, community noise would still be an obstacle to approval. The Supreme Court emphasised that while the Environmental Noise Regulations can be considered to determine the reasonableness of the relevant noise, they do not directly apply in the context of an application for development approval in the planning jurisdiction.

The Supreme Court’s views are consistent with planning decision making being concerned with ambient noise within a locality rather than the modelled predicted sound power levels (assigned noise levels) under the Environmental Noise Regulations. Albeit that the assigned noise levels provide some guidance.

What does this decision mean?

The decision provides further guidance (including the use by experts of evolving noise criteria from interstate jurisdictions and professional bodies) on the application of noise evidence in applications for development approval.

This case highlights the importance for experts that rely on proprietary or bespoke methodologies to subject those methodologies to review and be able to evidence why those methodologies remain appropriate.

The Tribunal may require a more conservative approach (including beyond that contemplated by a general guideline) to address the perceived context and requirements of a specific locality. This is particularly the case with noise emissions where guidance is based on modelled predicted sound power emissions without ambient modelling and validation from similar developments in similar locational context.

The decision also clarifies what the Tribunal’s role is in these proceedings. The Tribunal does not have to provide a detailed evaluation – it is enough that the opinion provided is supported by the evidence available.In this case, there was no legal error in the Tribunal taking a more conservative approach. The structure of the assigned noise levels under the Environmental Noise Regulations, was relevant to, but did not constrain the approach that the Tribunal could take.

While experts will naturally be drawn towards usual industry practice, care must be taken to ensure the methodologies used align with the statutory functions and discretions (including legal principles) to be applied.

This article was written by Mark Etherington, Partner, and Audrey Ooi, Law Graduate.

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