Tegni Cymru Cyf v The Welsh Ministers & Anor

On 20 May 2010 Wyn Williams J allowed an appeal by the developer Tegni Cymru Cyf against the decision of a Planning Inspector pursuant to Section 288 of the Town and Country Planning Act of 1990. This is the Welsh Ministers’ appeal, with the permission of Mummery LJ, against that decision. The respondent is represented by William Norris QC and James Burton. The appellant is represented by Mr Jonathan Moffett.

The proposed development is a wind farm at Gorsedd Bran to be sited within Clocaenog Forest, Denbighshire, close to the northern shore of Llyn Brenig. On 13 May 2007 the developer submitted a proposal to Denbighshire County Council seeking permission to construct 17 wind turbine generators. The generators would be 125 metres in height, with an overall capacity of up to 39.5 megawatts, sufficient to power just under 24,000 homes.

The nearest villages which would have been affected by the development were Bylchau, 2.5 kilometres to the north; and Nantglyn, three kilometres to the northeast. Properties within the hamlet of Waen were between 1.5 kilometres and 3.6 kilometres from the nearest turbine. The Inspector described the surrounding environment as follows:

“To the north of the Appeal Site is open moorland beyond which is the A543 which leads Denbigh to the A5 in the south. The Appeal Site is bounded to the east by upland farmland, to the south by an unclassified road linking Nantglyn to the B4501 and to the west by further coniferous plantation, beyond which is the Llyn Bran reservoir. The Appeal Site is approximately 290 ha in area and is situated at an elevation between 400m and 518m Above Ordinance Datum (“AOD”) which is the highest point in the immediate vicinity. However the turbines forming part of the proposed wind farm would be located below the 500m contour.

The Appeal Site is presently covered in coniferous forest, the felling of which will be necessitated by the construction of a proposed wind farm.”

At the time of the planning inquiry, there were already wind farms situated nearby at Tir Mostyn, and Foel Goch. Permission had already been granted for a further development at another nearby site at Brenig. On 23 January 2008, against the recommendation of the planning officer, the planning committee resolved to refuse permission for the development. On 2 April the full council refused permission on the following grounds specified in the notice:

The developer appealed, and between 5 and 9 October 2009 a public inquiry was held by Mr Stuart B Wild, the planning Inspector appointed by the Welsh Ministers. The developer adduced evidence from an expert in visual amenity, Mr Philip Roden, and noise, Mr Malcolm Hayes. The county council adduced evidence from an expert in landscape and visual amenity, Mr Iwan Evans, and relied upon the written expert evidence of a noise expert, Mr Bowdler.

I shall next consider the national and local policies relevant to an application of section 70(3) of the Town and Country Planning Act 1990, and section 38(6) of the Planning and Compulsory Purchase Act 2004. It is common ground that the principal national policy document for Wales relevant to the planning decision was TAN8. Wyn Williams J explained the effect of TAN8 as follows:

“37.

In paragraph 7 of his decision letter the Inspector identified TAN 8 as being the national policy most relevant to this case. It is necessary to describe some of its guidance in a little detail. First, TAN 8 advises that large scale on-shore wind development (defined to mean developments with generating capacity over 25 MW) should be concentrated into particular areas defined as Strategic Search Areas (SSAs). Seven such SSAs are shown within the Advice Note. One such SSA is designated within Clocaenog Forest. The indicative capacity for the whole area identified at Clocaenog Forest is 140MW. The SSA boundaries within TAN 8 are "at a "broad brush" scale". The Advice Note recognises that not all of the land within SSAs may be technically, economically and/or environmentally suitable for major wind power proposals.

38.

Annex C of TAN 8 contains much technical information relating to renewable energy technologies. In terms, however, one of its purposes is to contribute to the development control process (see paragraph 1.1). Paragraphs 2.14 to 2.16 contain important guidance in relation to the noise which may be generated by wind farms. The relevant parts of those paragraphs are as follows:-

‘2.14 Well designed wind farms should be located so that increases in ambient noise levels around noise-sensitive developments are kept to acceptable levels with relation to existing background noise. This will normally be achieved through good design of the turbines and through allowing sufficient distance between the turbines and any existing noise-sensitive development. Noise levels from turbines are generally low and, under most operating conditions, it is likely that turbine noise would be completely masked by wind-generated background noise. There are two quite distinct types of noise source within a wind turbine – the mechanical noise produced by the gear box, generator and other parts of the drive train and the aerodynamic noise produced by the passage of the blades through the air. There has been a significant reduction in mechanical noise since the early 1990s so the latest generation of wind turbines are much quieter than those first installed in Wales. Aerodynamic noise from wind turbines is generally unobtrusive – it is broad-band in nature and in this respect similar to, for example, the noise of wind in trees.

2.15

Wind generated background noise increases with wind speed, and at a faster rate than the turbine noise increases. The noise of the wind farm is therefore more likely to be noticeable at low wind speeds. Varying the speed of the turbines in such conditions can, if necessary, reduce the sound output from modern turbines.

2.16

The report, "the Assessment and Rating of Noise from Wind Farms" (ETSU-R-97), describes a framework for the measurement of wind farm noise and gives indicative noise levels calculated to offer a reasonable degree of protection to wind farm neighbours, without placing unreasonable restrictions on wind farm development or adding unduly to the costs and administrative burdens on wind farm developers or planning authorities. The report presents the findings of a cross-interest Noise Working Group and makes a series of recommendations that can be regarded as relevant guidance on good practice.’

39.

Annex D to TAN 8 contains guidance both relating to noise and visual impact. Paragraph 3.4 of this Annex suggests that 500 metres may be an appropriate separation distance between a wind turbine and residential property to avoid unacceptable noise impacts. However the same paragraph makes it clear that this limit should not be applied in a rigid manner. Section 6 of Annex D contains detailed guidance upon assessing the visual impact of a wind farm and its impact upon the landscape. Section 8 contains supplemental information on cumulative landscape and visual impact. During the course of oral submissions in particular, Mr Norris QC drew my attention to passages within those sections but for reasons which will become clear I do not think it necessary to set out the extracts to which I was referred.”

Thus, submitted Mr Norris QC, where the proposal complied with TAN 7 strong reasons would be required to depart from it. The Denbighshire Unitary Development Plan Policy MEW 10 provided as follows:

“40.

Policy MEW 10 of the Denbighshire Unitary Development Plan deals, specifically, with wind power. It is in the following terms:-

Wind turbines or wind farms, including any ancillary associated developments, will be permitted provided that:

...iii) the proposal will not unacceptably harm the character and appearance of the landscape especially the AONB, AOB, LLA’s, Historic Landscape or the Snowdonia National Park;

iv)

the proposal does not lead to unacceptable noise levels to residential amenity in the surrounding areas;

...

vii)

the proposal would not lead to an unacceptable cumulative visual impact in an area where zones of visibility overlap, particular attention would be paid to the potential effects of a proliferation of such developments in any one area;

viii)

the proposal does not cause unacceptable harm to the enjoyment of the landscape for recreational and tourism purposes ...”

A question arose in argument whether MEW 10(iv)’s reference to “unacceptable noise levels” permits a consideration not just of noise levels but also the frequency of occasions when noise is intrusive. In my judgment, reading MEW 10 in context, the decision maker is required to consider the consequences of a proposed development, which may, despite its approved situation, cause an unacceptable impact upon the community. I consider the words used to be wide enough to embrace not just the loudness of noise, but also the occasions and duration of noise. The Inspector noted that the National Assembly in Wales has, in respect of renewable energy, in general adopted policies compatible with those of the United Kingdom Government. He summarised his conclusions as to the provenance of those policies at paragraph 7 of his decision letter dated 18 November 2009:

“At the Welsh level I attach most weight to TAN 8 and the associated Ministerial statements. This site is located within Strategic Search Area A (SSA A) where one might expect large scale wind energy projects to be concentrated. This aspect carries considerable weight. SSA A has been the subject of further detailed study by Arup. I attach significant weight to the findings of that study which suggest that the appeal site performs well when compared to many other sites within SSA A. However not all sites within SSAs will be suitable. I must weigh the advantages of renewable energy from this proposal against any harmful effect of the proposal in judging this particular case on its merits, having regard to the Development Plan and the other material considerations.”

The Inspector considered the nature of the impact which would made upon the visual amenity of residence in the area. He recognised, as did TAN 8, that in the SSAs identified, including this one, some impact on visual amenity was inevitable. His task was to identify whether the development would render the impact “unacceptably harmful”. He concluded:

“13.

Mr Roden’s evidence included an assessment of the visual impact on most dwellings closest to the turbines together with representative assessments of the effect on groups of dwellings such as at Soar and Bylchau. He accepted that they were a representative selection identified off the ordnance survey map. It is perhaps unfortunate that the assessment omitted Nant Glyn, the second closest dwelling to the east. However I identified several other dwellings close to the site which were not included. These included the new bungalow on the approach track to Ty Newydd, Pennant Isa and the farm house on the lane leading up to Pen Y Lon. I was not trying to identify every dwelling which might not be affected but trying to assess the general level of visual impacts over a range of properties. However I came to the conclusion that this area contains a relatively large number of dwellings scattered across the countryside to the north and east of the site which would experience significant visual effects from the proposal.

14.

In terms of those effects becoming such that they would be unacceptably overbearing to residents I consider that they include the following properties; Wern Uchaf, Nant Gwyn, Rhiwiau, Cwm-y-rhinwedd, Pennant Isa, Nant-y-Garreg, Nant-y-Lladron, the Bungalow at the garage on the A543, the Sportsmans Arms, and the new bungalow on the approach to Ty Newydd. From at least all these properties the views of the turbines would be such that the presence of such large turbines located on the elevated appeal site would be overbearing.

15.

The cumulative effect of this proposal together with the existing and consented turbines would result in the local community having the appearance of becoming increasingly surrounded by turbines on all the high ground to the south and west. I consider that this proposal would be in conflict with UDP policy MEW10 criteria (vii).”

The developer challenged the Inspector’s findings before the judge, but his findings were upheld. As to the Inspector’s reasons in respect of noise nuisance, it is necessary to quote in full the Inspector’s reasons for his conclusions that the development would occasion an unacceptable level of noise which would conflict with UDP policy MEW 10 criteria (iv):

“21.

Turning to the more general effects of noise on the amenity of local residents I have no doubt that these turbines could, with the suggested, conditions, operate within or at the levels suggest in ETSU 97. These are the standards normally applied in Wales, however they are for guidance and are not absolute vales. The problem is that those noise levels do not mean that the turbines cannot be heard. Local residents gave a clear account of the noise from the existing turbines which they currently experience. Some of the descriptions may have been a little colourful but they do indicate a level of nuisance which is experienced and which would not normally trigger a breach of the planning conditions on Tir Mostyn.

22.

The experience of the noise is affected by the wind direction. On my visits in the area on the Thursday and Friday I experienced the difference as a result in the change of the wind direction. On the Thursday the wind was blowing towards the turbines from the dwellings in the valley opposite and I could not hear them. On the Friday the wind was blowing in the opposite direction and I could hear the turbines in a variety of locations where there was no other noise source. The consented Brenig turbines together with any at Clocaenog generally lie to the south of most of the neighbouring dwellings in the valley and to the south west of Nantglyn village centre. This means that any additional cumulative noise impact will be experienced when the wind blows from a southerly direction.

23.

Gorsedd Bran lies to the west and south west of the dwellings most affected by Tir Mostyn noise. This means that the prevailing wind would introduce additional noise to the same dwellings when they might currently expect not to hear the existing turbines. This would significantly increase the general noise nuisance experienced by a significant number of local residents. This cumulative increase in noise, whilst likely to be within ETSU 97 levels, would result in a level of harm which would conflict with UDP policy MEW10 criteria (iv).”

Annexe C, paragraph 2.16 of TAN 8 adopts ETSU-R-97, “The assessment and rating of noise from wind farms” (“ETSU”), an expert working party report on wind turbine noise. ETSU is the Energy Technology Support Unit sponsored by the Department of Trade and Industry. In the preface to its report, the authors say:

“This report describes the findings of a Working Group on Wind Turbine Noise. The aim of the Working Group was to provide information and advice to developers and planners on the environmental assessment of noise from wind turbines. While the DTI (now BERR) facilitated the establishment of this Noise Working Group this report is not a report of Government and should not be thought of in any way as replacing the advice contained within relevant Government guidance.

The report represents the consensus view of the group of experts listed below who between them have a breadth and depth of experience in assessing and controlling the environmental impact of noise from wind farms. This consensus view has been arrived at through negotiation and compromise and in recognition of the value of achieving a common approach to the assessment of noise from wind turbines.”

The members of the noise working group are set out in a preface to the report, and no doubt comprise eminent experts in the field in respect of which they were reporting. The report provides a framework for measurement of wind farm noise. It suggests indicative noise levels which were thought to offer a reasonable degree of protection to neighbours, while at the same time preventing unreasonable restrictions on development or its costs. The authors were, accordingly, attempting to strike a balance between the interests of wind farm neighbours and the public interest in wind farms. In its introduction, in the Executive Summary, to be found at III of the report, the authors say:

“The suggested noise limits and their reasonableness have been evaluated with regard to regulating the development of wind energy in the public interest. They have been presented in a manner that makes them a suitable basis for noise-related planning conditions or covenants within an agreement between a developer of a wind farm and the local authority.”

It follows from the foregoing that the work itself is the result of a working group discussion which, as the preface made clear, required compromise among the members of that group. It is to that extent a work based upon the subjective opinions of those engaged in the research. Nevertheless, it has acquired in England and Wales an almost unqualified acceptance as a framework by which considerations of applications for planning permission in respect of wind farms should be judged.

A condition of planning consent applied to the 25-turbine Tir Mostyn/Foel Goch development, based upon ETSU, was that the operational noise limit should be 40 decibels (“dBs”), or background noise plus 5 dBs. TAN 8 did not impose ETSU upon decision makers. Paragraph 2.16 concluded:

“The report presents the findings ... and makes a series of recommendations that can be regarded as relevant guidance on good practice.”

The report contains an important acknowledgment at paragraph 16, which is relevant in the context of the present case:

“The Noise Working Group is of the opinion that absolute noise limits and margins above background should relate to the cumulative effect of all wind turbines in the area contributing to the noise received at the properties in question. It is clearly unreasonable to suggest that, because a wind farm has been constructed in the vicinity in the past which resulted in increased noise levels at some properties, the residents of those properties are now able to tolerate higher noise levels still. The existing wind farm should not be considered as part of the prevailing background noise.”

The report did not, however, have a specific contribution to make to a situation in which the issue was not noise level, but the frequency of occasions when noise intruded on amenity. It is, in addition, important to record the acknowledgment in TAN 8 that suitability of a site for development is ultimately a matter of judgment, even within the boundaries of an SSA.

At paragraph 2.3 and 2.4 of TAN 8 appears the following:

“2.3

SSAs have been identified through a variety of means as outlined below in paragraphs 2.4-2.9 and in the Arup Final Report 2004. This approach addresses the issue of location of onshore wind facilities at a strategic all-Wales level. Local planning authorities are best placed to assess detailed location requirements within and outside SSAs in the light of local circumstances.

Strategic Search Areas (SSAs)

2.4

The 7 Strategic Search Areas (SSAs) are shown on Maps 1-8 [Clocaenog Forest is situated within SSA 8]. The SSA boundaries are at a ‘broad brush’ scale. Not all of the land within the SSAs may be technically, economically and/or environmental suitable for major wind power proposals; however the boundaries are seen as encompassing sufficient suitable land, in one or more sites, to deliver the Assembly Government’s energy policy aspirations. It is a matter for local planning authorities to undertake local refinement within each of the SSAs in order to guide and optimise development within each of the areas. […]”

The judge made a number of criticisms of the Inspector’s reasons at paragraphs 65 to 72 of his judgment. They can be summarised as follows.

The learned judge’s reference to the fact that none of the residents lived 500 metres or less from its nearest turbine needs explanation. As the Arup Report for Denbighshire County Council, “TAN 8 Annex D study of Strategic Search Area A – Clocaenog Forest” emphasises:

“There is an emerging best practice approach within the onshore wind industry of siting development a minimum of 500m from residential properties (for noise/amenity and safety reasons).”

Reference to the emerging standard appears also in the terms of TAN 8.

Wyn Williams J drew upon the authority of South Bucks District Council v Porter (No 2) [2004] 1 WLR 1953 for its guidance as to the adequacy of reasons:

“36.

The reasons for a decision must be intelligible and they must be adequate. They must enable the reader to understand why the matter was decided as it was and what conclusions were reached on the ‘principal important controversial issues’, disclosing how any issue of law or fact was resolved. Reasons can be briefly stated, the degree of particularity required depending entirely on the nature of the issues falling for decision. The reasoning must not give rise to a substantial doubt as to whether the decision-maker erred in law, for example by misunderstanding some relevant policy or some other important matter or by failing to reach a rational decision on relevant grounds. But such adverse inference will not readily be drawn. The reasons need refer only to the main issues in the dispute, not to every material consideration. They should enable disappointed developers to assess their prospects of obtaining some alternative development permission, or, as the case may be, their unsuccessful opponents to understand how the policy or approach underlying the grant of permission may impact upon future such applications. Decision letters must be read in a straightforward manner, recognising that they are addressed to parties well aware of the issues involved and the arguments advanced. A reasons challenge will only succeed if the party aggrieved can satisfy the court that he has genuinely been substantially prejudiced by the failure to provide an adequately reasoned decision.”

Mr Moffett argues that there was no deficiency of reasoning in the Inspector’s decision letter. He was plainly expressing his planning judgment in the light of his own inspections. This was, Mr Moffett submits, a perfectly legitimate approach to the Inspector’s task. Mr Moffett relies upon the judgment of Carnwath J, as he then was, in British Aerospace Plc v Secretary of State for the Environment [1997] EWHC 556 (Admin) at paragraphs 38, 43, 45 and 46. The decision in British Aerospace concerned development at Filton and an asserted increase in noise nuisance. The criticism made of the reasoning of the Inspector and the Secretary of State appears at my Lord’s judgment at paragraph 38:

“38.

Mr Taylor made a detailed critique of the reasoning of the Inspector and the Secretaries of State on the noise issues. While the degree of technical detail to which he descended was unusual for a legal challenge of this kind, I accept that to a large extent it was necessary to set the groundwork for his submissions of principle. Indeed, it was part of his case that noise is a technical subject, which parties are encouraged by Government policy guidance to approach with the benefit of technical advice and according to established criteria. Thus for example, PPG 24 Annex 3 gives specific guidance on the assessment of noise from aircraft and invites those concerned to seek technical advice on the applicable indices and noise contours from the Department of Transport and the Civil Aviation Authority. Thus, in this case the main parties were assisted by technical witnesses, and the Inspector had the assistance of a technical assessor to evaluate the evidence. This no doubt is a recognition that the subjective reactions of individuals to the prospect of an airport use, based on their experiences elsewhere, may not be a very objective or reliable way of judging the matter, and that there are now well developed and tested means of reaching an evaluation.”

Having considered some of the details of the submissions made, my Lord turned at paragraph 44 to the legal effect of those submissions:

“44.

I have considerable sympathy with Mr Taylor's general point, and his comments on the individual points I have mentioned. Given the time and expense on technical noise evidence, which attempted to follow the guidance in PPG 24 and other official advice, it is unsatisfactory that at the end of the day it is not clear how the conclusions of the Secretaries of State relate to that guidance or to the technical evidence based on it.

45.

Mr Taylor's difficulty however, is to convert this into a point of law, or to show that it would have affected the ultimate decision. It is clear that as a matter of law, the Secretaries of State and the Inspector were entitled to reach their own conclusions on the noise issue, even though that might conflict with the technical evidence before them. It seems to me highly desirable, as a matter of policy and practice, that the Inspector and the Secretaries of State should follow the framework established by the technical guidance and evidence. But I know of no principle of law which says that they are bound by that approach. This point was forcibly expressed by Forbes J in Westminster Renslade Ltd -v- Secretary of State [1983] 48P&CR 255, 263. He was there referring to the Inspector's conclusion, contrary to the appellants' technical evidence, that:

‘the subjective reaction of the people affected would be quite out of proportion to the increase in noise level’.

He said:

‘One asks oneself why on earth an expert planning inspector should not have come to that conclusion perfectly properly, even if he had every single noise expert in the country ranged on the appellants' side. It does not seem to me that he is saying that there is necessarily going to be a tremendous lot of noise; he is putting it squarely on the point that this is a deprived area in the sense that it is an area that is now deprived of any form of silence and that if one intrudes more noise into that sort of environment one must expect people to react pretty sharply. It seems to me that that is a perfectly proper view for an informed inspector to take, so, in my view, he was entitled to take the view that he did take.’

46.

Although that case was not specifically referred to in argument before me, it expresses an approach which, in my view, is unassailable as a matter of law.”

In other words, my Lord was emphasising the desirability of the application of a recommended noise assessment framework, notwithstanding that the Inspector was entitled to make his own judgment upon the evidence.

In the present case, I do not understand the Inspector to have been rejecting the proposition that the development would have complied with indicative levels recommended by the relevant framework. What he did was to experience the level of noise interference for himself. It is noteworthy that the Inspector had granted permission for Tir Mostyn and Foel Goch in the past, and was therefore experienced in dealing with the issues raised by wind farm developments. In the final paragraph of his decision letter, the Inspector said that:

“...this proposal would be in serious conflict with the appropriate UDP policy. The benefits of the provision of renewable energy would not outweigh the benefits I have identified. The imposition of conditions would not overcome those strong planning objections.”

I therefore turn to examine the Inspector’s reasoning. First, as I have said, the Inspector recognised that the turbines could operate within the conditions imposed at indicative levels. However, the evidence of residents had made it plain that the planning conditions imposed at Tir Mostyn did not in fact prevent noise intrusion. The residents had given clear evidence of their experiences. While the Inspector made allowance for the risk of hyperbole in some of the descriptions given, he accepted that while operating levels of noise at Tir Mostyn would not constitute a breach of condition, they nevertheless created “a level of nuisance” to residents. The Inspector, as he explained, meant by “a level of nuisance” an interference with amenity at the residents’ properties.

It is to be noted that the Inspector did not conclude that the noise level produced, or the frequency of occasions when noise was intrusive, was in hindsight at unacceptable levels. The Inspector stated at paragraph 4 of his report that he made several unaccompanied visits to the area, “to view the proposal from the majority of viewpoints along the local road network”. On Thursday, 8 October 2009, he visited “a number of residential properties closest to the site”. After the closure of the inquiry on Friday, 9 October, he made further visits to the public highways outside dwellings and properties closest to the proposal. He continued:

“It is on the basis of my personal visits to the area that I made my judgments on the effect of the proposal ...”

During his Thursday visit, the Inspector noted that the wind direction was from the position of most of the dwellings concerned towards the site at Tir Mostyn; that was, therefore, a wind from the west and north. The result was that the noise of the turbines could not be heard at those dwellings. On Friday, however, the wind direction was reversed, and the noise of the turbines at Tir Mostyn was clearly audible. The Inspector then considered what would be the additional effect of the construction of the turbines for which permission had already been granted at Brenig. He noted that the turbine sites lay south of most of the dwellings in the Aton Ystrad Valley, and to the southwest of the population centre at Nantyglyn Mountains. Gorsedd Bran, the proposal site, lies to the west and southwest of those dwellings most affected by noise from Tir Mostyn. The prevailing wind in Wales is westerly. It followed, in the Inspector’s view, that the impact of noise upon the residents of the valley would increase significantly if the proposed development was added to those already in place and already consented. He called the impact a significant increase in “the general noise nuisance”; by which we know he meant the intrusion of noise upon the amenity of the dwellings.

I detect no irreconcilable inconsistency in the Inspector’s findings. He acknowledged that the cumulative noise effect of the proposed development would not fall outside the ETSU indicative levels, but having experienced the existing noise for himself, he was satisfied that the proposed development would result in a level of harm which would conflict with MEW 10(iv). What he was deciding was that ETSU indicative levels in relation to the proposal which he was considering were not the last word on “acceptable” noise levels. The learned judge himself acknowledged that they did not represent an absolute standard against which the proposal was to be judged. At paragraphs 63 and 68 of his judgment, the judge said:

“63.

I am not persuaded that there is a base-line principle operating with the inflexibility suggested by Mr Norris when the issue of noise is under consideration either by a local planning authority or an Inspector upon appeal. Ultimately, a planning judgment has to be made about objections to a proposed development which relate to the noise generated by that development. However, as is clear both from TAN 8 itself and from policy MEW 10(iv) an objection to a proposed wind farm situated within an SSA which is based upon noise can only be justified if an Inspector reasonably concludes that the noise levels associated with the proposed development will be unacceptable.

...
68. In my judgment the Inspector is clearly correct when he says (as he does in paragraph 21 of the decision letter) that the indicative noise levels set out in ETSU-R-97 are guidance not absolute values. That is the clear effect of paragraph 2.16 of TAN 8. It follows that there may be circumstances in which it is open to a local planning authority or an Inspector to conclude that noise levels associated with a wind farm are unacceptable notwithstanding compliance with ETSU-R-97. However, on the basis of that which is set out in the decision letter, the Inspector's statement in these proceedings and the documentation put before me, my tentative view is that this conclusion is not justified. On that basis it would be my duty to hold that the Inspector had reached a decision on the issue of noise which was unreasonable in the Wednesbury sense.”

It seems to me that at the heart of the judge’s criticism lay the lack of detail in the Inspector’s reasons for reaching the conclusion he did. I conclude with some diffidence, having regard to the judge’s extensive experience in this field, that there was in reality no deficiency in the Inspector’s reasoning. I accept that there was a lack of detail, but I do not consider that it affected the cogency or the lawfulness of his decision. The steps implicit in the Inspector’s reasoning were the following:- (1) his own perception of existing noise, and its level of intrusion, as described in the evidence, established the baseline from which he was to make his planning judgment as to the additional impact of the proposal; (2) his judgment, by analysis of local weather conditions, of the increased impact of noise which would be generated in the valley when all consented developments were completed. This is not an Inspector without experience of these matters. Had he been entirely new to the ETSU expertise, it may be that he could have been expected to enter into an analysis of those conclusions by comparison with his own observations made throughout the valley. However, the Inspector was sufficiently familiar with the issues, and with the expertise, to be able to start from the premise that the development would comply with its indicative levels; and to judge whether, notwithstanding compliance with those levels, the residents were justified in their fear of the consequences of permission.

I do not believe it was a requirement for adequacy of reasons that the Inspector should have described property by property what his sensation was. Every interested party knew whose evidence he was testing by his site visits. There was a list of the relevant witness statements attached to his report. Furthermore, this was not an occasion for measurement of noise. Had the Inspector embarked on such an exercise, he would have been justifiably criticised. It was an occasion for testing the evidence he had heard against experience and impression. It seems to me that he went about that exercise carefully and rationally, and explained it to the reader of his report.

I have reached the conclusion that the judge was tempted into a textual analysis of the decision letter when none was appropriate. Read as a whole the relevant paragraphs reveal an acceptable line of reasoning towards the Inspector’s conclusion. None of the parties could really be in any doubt what was the basis for his planning judgment.

Mr Norris QC sought to persuade us that the judge should have gone further than he did, and hold not only that the Inspector’s reasons were inadequate, but that the decision itself was irrational. His premise is that there should be consistency in decision making, particularly where there is a policy presumption in favour of development. This amounts to a submission that since the indicative levels established by the ETSU report would have been complied with upon the Inspector’s findings had the proposal gone ahead, then there were no grounds upon which permission could rationally be refused. If, submitted Mr Norris QC, the Inspector was to depart from what he suggests was a conventional application of TAN 8, then he must have had a very good reason to do so; and if he did, it should have been stated.

The implication of the argument is that when a decision maker is faced with a third application for a wind farm in an identified SSA, there is a presumption that the third decision will follow the first two. I cannot accept this argument. The consistency required is as to the planning approach, that is, to apply policies TAN 8 and MEW 10 unless material considerations indicate otherwise. This, it seems to me, is exactly what the Inspector did. Applying TAN 8 and MEW 10, he found for sustainable reasons that permission for a third wind farm in close proximity to settlements in the Aton Ystrad Valley would cause unacceptable harm. In my judgment, the decision was neither irrational, nor was it defectively reasoned.

Mr Norris additionally sought to undermine the Inspector’s decision as to visible impact on amenity. The criticism is that since the properties were all more than 500 metres away from the nearest turbine, and since the site was within a TAN 8 SSA, it was insufficient to describe the effect of the proposed development as “overbearing”. It is contended that the Inspector should have given particulars in his judgment that the proposal would have had an overbearing impact. Again, the Inspector did not consider the proposal site in isolation, although he did deal with specific properties in respect of which he considered the proposal would be overbearing. He continued that consent to the proposal would:

“... result in the local community having the appearance of becoming increasingly surrounded by turbines on all the high ground to the south and west.”

In my judgment, the Inspector could hardly have been more explicit in his demonstration of the effect of the proposal.

For these reasons, I would allow this appeal.

I agree, and will add just a few words. There are powerful policy reasons for the development of wind farms, and a range of policy statements both in Wales and in the UK generally stress the importance of farms for renewable energy. These developments will almost inevitably interfere with the amenity of local inhabitants. They increase the noise to which they are subject, and they interfere with their views. Certain policy documents give guidance as to the considerations which an inspector should take into account when determining whether to grant planning permission. In this case, the relevant policy concerning noise is contained in MEW 10, which provides that the developments will be permitted provided that “... the proposal does not lead to unacceptable noise levels for residential amenity in the surrounding area.”

As the Inspector observed, the indicative levels identified in ETSU-R-97 are the standard normally applied in Wales. He recognised in this case that the cumulative noise levels from the existing wind farm at Tir Mostyn, the proposed wind farm at Brenig for which planning permission has been granted, and the wind farm in this proposed development at Gorsedd, would still be within the noise levels in ETSU-R-97. Nevertheless, he considered that the level of noise would conflict with the policy in MEW 10 because it would be an unacceptable level and would involve noise at times when currently there was no noise at all.

The ETSU standard, as with most guidelines, recognises that a balance has to be struck between the public interest in the development and the interference with private rights. It assists an inspector in determining how that balance should be struck so far as noise is concerned. It does not, of course, mean that individuals will not be adversely prejudiced even by noise levels which fall below the maximum indicated in the ETSU guidelines, but they will generally have to put up with that noise in the wider public interest.

In this case, the inspector had unchallenged evidence from the residents as to the effect on their lives of the existing noise level, and he had the benefit of his own visit to the site. He recognised, as I think his decision fairly indicates, that the existing wind farm at Tir Mostyn caused a nuisance to the residents, in the sense that it involved a level of interference with the amenity which they found irritating. But the degree of interference would depend upon the direction of the wind. The frequency of that interference would increase with the development at Brennigh, and if the development at Gorsedd Bran were permitted then it would mean that the prevailing westerly wind would yet further increase the frequency of the noise interference. He found that a significant number of residents would be subject to additional noise at times where currently they may be subject to none. On this basis, he considered that the level of noise was unacceptable. To put it colloquially, it seems to me that he thought “enough is enough” as far as these residents were concerned.

Mr Norris QC submits that this involved an error of law. The volume of noise did not increase, merely the frequency. He contended, as I think he had to do, that the increase in the frequency of noise was not a material factor for the Inspector to consider. Furthermore, he said it would undermine the consistency which the guideline is intended to provide, if in effect an Inspector could depart from it in this way. The guidelines were grounded in an objective analysis of noise levels, and it was not appropriate to depart from a guideline merely as a consequence of his consideration of the subjective perceptions of the residents.

I disagree. As my Lord, Lord Justice Pitchford, has indicated, it seems to me that the duration of an interference is plainly a material consideration when determining whether the level of noise is acceptable. I see the force of Mr Norris QC’s submission that there is a degree of uncertainty and inconsistency if guidelines such as those enunciated in ETSU 97, based on objective evidence, are departed from too readily; but as Carnwath J, as he then was, pointed out in the Filton case to which Pitchford LJ has referred, ultimately the legal position is that it is for the planning inspector to exercise his judgment. Provided he has had regard to material considerations and has not reached perverse conclusions, then it is not for the court to interfere.

Plainly, the Inspector had regard to the guidance in ETSU 97. He recognised that it would not be infringed. Nonetheless, he was satisfied that the increase in the frequency of the noise would be unacceptable. He had a proper evidential basis for that conclusion, he explained his reasons adequately, and I see no error of law in his analysis.

Accordingly, the appeal must succeed.

I agree with both judgments. I would add one observation. As my Lords pointed out, the basis of the Inspector’s conclusion was that it was relevant to consider the extent to which the addition of another wind farm would increase the duration of the time during which the noise would be heard, rather than simply the level of noise at any particular time. That does not sound a particularly surprising observation. Looking through the residents’ letters, for example, I find one objector who says that at his home they already experience a reasonably high level of disturbance from the existing turbines at Tir Mostyn, but he continues:

“Luckily, our prevailing wind is southerly, meaning that only when southerly wind blows we experience nuisance. The Gorsedd Bran site is to our southwest, i.e. the direction from which the wind blows most frequently. We know that should these turbines be approved, we will be subject to many more days and nights of disturbance. We therefore object strongly to the application.”

That reflects the concerns of a number of residents, and was clearly an issue that the Inspector had to consider. My observation is that it is surprising if, as we are told, that situation is not dealt with in the relevant guidance. We have heard that the ETSU guidance deals with the cumulative impact in respect of noise levels, but it does seem odd that it does not deal in terms with duration. That perhaps needs to be looked at in order to meet Mr Norris’s reasonable concern that developers should have guidance on which they can work in planning future schemes.

Just one further point, and I put this broadly. At a number of points in your Lordships’ judgments you referred to the frequency of the noise; of course “frequency” --