Mount Salus Residents Owners Management Company Limited By Guarantee v An Bord Pleanála & Ors

APPROVED NO REDACTION NEEDED THE COURT OF APPEAL CIVIL Appeal Number: 2025/86 2025/87 Neutral Citation Number [2026] IECA 28 Allen J. Meenan J. Collins J. IN THE MATTER OF SECTION 50 OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) BETWEEN MOUNT SALUS RESIDENTS OWNERS MANAGEMENT COMPANY LIMITED BY GUARANTEE APPLICANT - AND – AN BORD PLEANÁLA, THE MINISTER FOR HOUSING, LOCAL GOVERNMENT AND HERITAGE, IRELAND, THE ATTORNEY GENERAL, AND THE PLANNING REGULATOR RESPONDENTS AND ALANNAH SMYTH AND DÚN LAOGHAIRE-RATHDOWN COUNTY COUNCIL NOTICE PARTIES JUDGMENT of Mr. Justice Allen delivered on the 12th day of March, 2026 Introduction 1. This is an appeal against the judgment of the High Court (Holland J.) delivered on 15th January, 2025 ([2025] IEHC 14) and so much of the consequent order made on 10th March, 2025 as declared invalid two statutory recommendations issued by the Office of the Planning Regulator (“OPR”) to Dún Laoghaire-Rathdown County Council (“DLRCC”) under s. 31AM(8) and s. 31AN(4) of the Planning and Development Act, 2000 (“PDA 2000”); and a statutory draft direction and a statutory direction issued by the Minister for Housing, Local Government and Heritage (“the Minister”) to DLRCC under s. 31 of PDA 2000, directed to a zoning objective in the Dún Laoghaire-Rathdown County Development Plan, 2022 to 2028. 2. On 1st November, 2022 An Bord Pleanála (“the Board”) decided to grant permission to the first notice party, Ms. Alannah Smyth (“Ms. Smyth”) for the construction of a house at Torca Road, Dalkey, near the affluent Mount Salus residential development. On the application of Mount Salus Residents Owners Management Company Limited by Guarantee (“Mount Salus”) by way of judicial review of the decision of the Board, the Board accepted that it had misconstrued part of the Development Plan, and that Mount Salus was entitled to an order of certiorari. Ms. Smyth did not oppose certiorari and it was agreed that the matter should be remitted to the Board. 3. One of Mount Salus’s grounds – Core Ground 6 – was that the Board’s decision was invalid because it was based on the impugned recommendations of the OPR and directions of the Minister which, Mount Salus contended, exceeded the powers conferred on them by ss. 31, 31AM and 31AN of PDA 2000; and were inadequately reasoned, unreasonable, irrational, and therefore invalid. 4. The effect of the impugned directions was to remove from the Development Plan a “0/0 Objective” which restricted development in the designated “0/0 zones”, which included parts of Killiney and Dalkey. The practical issue in the High Court and on the appeal is whether the reconsideration by the Board of Ms. Smyth’s appeal should be by reference to the Development Plan with, or without, the 0/0 Objective. Strictly speaking, the decision of the Board was not – as the ground suggests – based on the impugned recommendations and directions but on the Development Plan as modified by the Minister’s direction but nothing turns on the precise formulation of the ground. 5. As I will come to, it is common case that the power conferred on the Minister to direct a planning authority to amend – or, more accurately, to correct – a Development Plan is dependent on a recommendation of the OPR. It is agreed that if the recommendation – or purported recommendation – of the OPR is invalid, the Minister’s direction falls away. Thus the focus of the argument was on the legal validity of the recommendations of the OPR. 6. The premise of the opinion of the OPR on which its recommendations were based was that the 0/0 objective was inconsistent with a national policy objective to deliver new homes within the existing built-up footprint, and a regional policy objective to achieve compact urban development targets within or contiguous to the built up areas of Dublin city and suburbs; with the consequence – in the opinion of the OPR – that the DLRCC Development Plan failed to set out an overall strategy for the proper planning and sustainable development of the area. 7. The judgment of the High Court – which ran to 153 pages – was comprehensive but the gravamen of it was that the OPR (and later the Minister) focussed on specific planning policy objectives rather than the planning policy objectives as a whole; and focussed on pockets of the planning area rather than the area as a whole; and thereby, in assessing whether the development plan complied with the requirements of PDA 2000, asked itself the wrong question. 8. The core issue in the appeal is whether the OPR, in forming the opinion which it did, was entitled to focus on particular policy objectives rather than on the national and regional policy objectives as a whole; and was entitled to focus on the particular areas zoned 0/0 rather than on the local authority area as a whole. Factual background 9. Among the leafiest suburbs of South County Dublin, in the functional area of DLRCC, are the seaside villages of Dalkey and Killiney. Surrounding the villages are significant numbers of large Victorian houses on substantial grounds. Much of the neighbourhoods is designated as Architectural Conservation Area. Many of the buildings are Protected Structures and have other heritage designations. 10. Each of the villages is served by a DART station. As the judge put it, certain lands in the Killiney/Dalkey area along the DART line are simultaneously suited to large scale, high density, residential development by virtue of their proximity to the DART line – and specifically the DART stations – consistently with planning policy objectives of compact urban residential development along transport corridors; and unsuited to such development by reason of their architectural heritage, the protection of which is consistent with another planning policy objective. 11. On 3rd January, 2020 DLRCC issued its draft Development Plan, 2022 to 2028 Issues Paper for public consultation. The draft plan – as did the existing plan – incorporated an objective for a “0/0 Objective” which, in order to protect the amenities of those areas, would restrict development of designated 0/0 Zones, in which central government policy would otherwise support higher densities. The OPR first made a submission on the draft plan requesting DLRCC to reconsider the 0/0 Zoning; then issued a Recommendation to DLRCC that the 0/0 Zone objective be omitted; and then issued a recommendation to the Minister that a direction under s. 31 PDA 2000 was merited. The Minister gave notice to DLRCC of his intention to issue a direction, and then issued a direction for the deletion of the 0/0 Objective of the plan, which by then had been adopted by the elected members of DLRCC. By s. 31(17) PDA 2000 the direction issued by the Minister was deemed to have immediate effect and its terms considered to be incorporated into the plan. The statutory framework 12. It is useful to start by examining the statutory framework. 13. Section 10(1) PDA 2000 requires that a development plan shall set out an overall strategy for the proper planning and sustainable development of the area of the development plan and shall consist of a written statement and a plan or plans indicating the development objectives for the area in question. 14. Section 10(1A) provides that:- “(1A) The written statement referred to in subsection (1) shall include a core strategy which shows that the development objectives in the development plan are consistent, as far as practicable, with national and regional development objectives set out in the National Planning Framework and the regional spatial and economic strategy and with specific planning policy requirements specified in guidelines under subsection (1) of section 28.” 15. Section 10(1D) provides that:- “(1D) The written statement referred to in subsection (1) shall also include a separate statement which shows that the development objectives in the development plan are consistent, as far as practicable, with the conservation and protection of the environment.” 16. Section 10(2A)(a) provides:- “(2A) Without prejudice to the generality of subsection (1A), a core strategy shall – (a) provide relevant information to show that the development plan and the housing strategy are consistent with the National Planning Framework and the regional spatial and economic strategy and with the specific planning policy requirements specified in guidelines under subsection (1) of section 28.” 17. In the scheme of PDA 2000, the making of the development plan is in the first instance a matter for the planning authority, specifically for the elected members. Section 31 as originally enacted conferred a power on the Minister for the Environment and Local Government, if he or she considered that a development plan failed to set out an overall strategy for the proper planning and sustainable development of the area of a planning authority or otherwise significantly failed to comply with the Act, to intervene by directing the authority to take such measures as the Minister might require to review or vary the development plan to ensure compliance with the Act. It is worth emphasising that the power conferred on the Minister by s. 31 to intervene – then and now – is directed to ensuring compliance with the requirements of the Act. 18. The power originally conferred on the Minister to issue directions to a planning authority was later tempered by the interposition of the OPR so that it was available only on a recommendation of the OPR. 19. The OPR was established in April, 2019 by s. 31M PDA 2000, which was inserted by s. 4 of the Planning and Development (Amendment) Act, 2018. Section 31N provided for the appointment of a chief executive of the OPR, to be known as the Planning Regulator. 20. The functions of the OPR are set out in s. 31P and include the evaluation and assessment of development plans and draft development plans during their preparation and making; the provision of observations and recommendations to planning authorities on those plans; and, in respect of any draft plan or plan, to inform the Minister if, in the opinion of the Office, any such plan is not consistent with its observations and recommendations, especially where, in its opinion, the failure to be so consistent would affect the overall strategy for the proper planning and sustainable development of the area concerned. 21. Section 31AM PDA 2000 provides for the evaluation and assessment by the OPR of development plans at each stage of their planning, preparation and making; and for the making by the OPR of observations, submissions and recommendations. Section 31AM(6) contemplates that a planning authority may decide not to comply with a recommendation of the OPR and, in such event, requires that notice of any such decision be given by the local authority to the OPR specifying the reasons for the decision of the planning authority. 22. Section 31AM(7) is peculiar. It contemplates that after a planning authority has notified the OPR that it – the planning authority – has decided not to comply with a recommendation, the OPR should further consider whether or not the development plan as made is, in the opinion of the OPR, consistent with any recommendations made by the Office. I confess some difficulty understanding how a development plan made otherwise than in compliance with a recommendation might nevertheless be consistent with a recommendation which the planning authority has decided not to comply with. If what was intended was that the OPR might reconsider a recommendation in the light of the planning authority’s decision and the reasons given for it, s. 31AM(7) does not unambiguously say so. 23. Section 31AM then provides that:- “(8) Where subsequent to any consideration for the purposes of subsection (7), the Office is of the opinion that— (a) the development plan or the variation of it, as the case may be, has not been made in a manner consistent with the recommendations of the Office, (b) that the decision of the planning authority concerned results in the making of a development plan, or its variation, in a manner that fails to set out an overall strategy for the proper planning and sustainable development of the area concerned, and (c) as a consequence of paragraphs (a) and (b), the use by the Minister of his or her functions to issue a direction under section 31 would be merited, then the Office shall issue, no later than 4 weeks after the development plan or the variation to the development plan is made, a notice to the Minister containing— (i) recommendations that the Minister exercise his or her function to take such steps as to rectify the matter in a manner that, in the opinion of the Office, will ensure that the development plan, or the development plan as varied by the planning authority, sets out an overall strategy for proper planning and sustainable development, and (ii) a proposed draft of a direction to which paragraph (c) would relate.” 24. I paused here to say that it is common case that the requirements of s. 31AM(8)(a), (b) and (c) are cumulative but it seems to me that the core requirement – certainly for present purposes – is that the OPR must be of the opinion that the development plan fails to set out an overall strategy for the proper planning and sustainable development of the area concerned; including – as required by s. 10(1A) – a core strategy which shows that the development objectives are consistent, as far as practicable, with national and regional development objectives. 25. The next stage in the process is prescribed by s. 31AN, the first step in which is that:- “31AN. - (1) The Minister shall consider the recommendations of the Office in the notice issued under section 31AM and - (a) where the Minister agrees with that notice, then the Minister shall proceed, pursuant to section 31, to issue a notice for the purposes of subsections (3) and (4) of that section having taken account of the proposed draft direction submitted by the Office, or (b) where the Minister does not so agree with the Office, then the Minister shall— (i) prepare a statement in writing of his or her reasons for not agreeing, (ii) cause that statement to be laid before each House of the Oireachtas, and (iii) as soon as practicable, make that statement available on the website of the Department of Housing, Planning and Local Government.” 26. Thus, the Minister must form his or her own view on a recommendation of the OPR and having done so, may act on it or, if he or she does not agree with the OPR, must explain to the Oireachtas and the public the reasons for any such disagreement. The scheme of the legislation recognises that there is scope for disagreement between the OPR and the Minister. It may be that the disagreement is limited to whether the circumstances are such that the use by the Minister of his or her functions to issue a direction under s. 31 would be merited, but in principle the disagreement may be as to whether the development plan sets out an overall strategy for the proper planning and sustainable development of the area concerned. In such a case, the Minister’s disagreement with the opinion of the OPR would be tantamount to agreement with the view of the local authority that the development plan was in compliance with the statutory requirements. 27. As I will come to, there was on the appeal, as there was in the High Court, a great deal of talk of unreasonableness and irrationality but this, in my opinion, was a distraction. The objective of PDA 2000 is to ensure that development plans set out an overall strategy for the proper planning and sustainable development of the local authority areas. The primary obligation to achieve this is imposed on the planning authority. The local authority’s compliance with that obligation is subject to the supervisory role of the OPR and the Minister. The OPR is an independent, expert, statutory body whose function is to evaluate and assess development plans and form an opinion as to their compliance with the requirements of the Act. That is a matter of judgment on which, it seems to me, there is scope for legitimate and respectful difference of opinion. In the ordinary understanding of the word, the OPR’s evaluation and assessment of a development plan might be said to be a review of the plan but I think that the use of the word review in this context would court confusion between the evaluative function of the OPR and judicial review. Similarly, an analysis in terms of reasonableness and irrationality of what is in truth a legal issue as to the basis of the OPR’s opinion is calculated to increase the heat while diminishing the light. 28. Section 31 PDA 2000 (as substituted by the Planning and Development (Amendment) Act, 2018) provides insofar as is material for present purposes that:- “31.—(1) Where the Minister is of the opinion that— (a) a planning authority, in making a development plan, … has failed to— (i) implement a recommendation made to the planning authority by— … (II) the Office of the Planning Regulator under section 31AM or 31AO, or (ii) take account of any submission or observation made to the planning authority by— … (II) the Office of the Planning Regulator under section 31AM or 31AO, (b) in the case of a plan, the plan fails to set out an overall strategy for the proper planning and sustainable development of the area, (ba) a plan is not consistent with— (i) the national and regional development objectives set out in the National Planning Framework and the regional spatial and economic strategy, (ia) … (ii) specific planning policy requirements specified in guidelines issued by the Minister under subsection (1) of section 28, (c) the plan is not in compliance with the requirements of this Act, or (d) … then, subject to compliance with the relevant provisions of sections 31AM and 31AN or sections 31AO and 31AP, as the case may be, the Minister may in accordance with this section, for stated reasons, direct a planning authority to take such specified measures as he or she may require in relation to that plan. (2) Where the Minister issues a direction under this section the planning authority, notwithstanding anything contained in Chapter I or II of this Part, shall comply with that direction and the chief executive or elected members shall not exercise a power or perform a function conferred on them by this Act in a manner that contravenes the direction so issued. (3) Before he or she issues a direction under this section, the Minister shall, no later than 6 weeks after a plan is made, issue a notice in writing to a planning authority consequent on a recommendation being made to him or her by the Office of the Planning Regulator under section 31AM(8) or 31AO(7), as the case may be. (4) The notice referred to in subsection (3) shall, for stated reasons, inform the planning authority of— (a) the forming of the opinion referred to in subsection (1), (b) the intention of the Minister to issue a direction (a draft of which shall be contained in the notice) to the planning authority to take certain measures specified in the notice in order to ensure that the plan is in compliance with the requirements of this Act and sets out an overall strategy for the proper planning and sustainable development of the area, (c) those parts of the plan that by virtue of the issuing of the notice under this subsection shall be taken not to have come into effect, been made or amended under subsection (6), and (d) … (5) … (6) (a) Notwithstanding section 12(17), 13(11) or 20(4A), a plan shall not have effect in accordance with those sections in relation to a matter contained in the plan which is referred to in a notice under subsection (3). (b) If a part of a plan proposed to be replaced under section 12, 13 or 20 contains a matter that corresponds to any matter contained in that plan which is referred to in a notice under subsection (3), that part shall not, save where subsection (17) applies, cease to have effect in respect of that matter. … (16) Where paragraph (a) of section 31AN(4A), paragraph (a) or (c) of section 31AN(9), paragraph (a) of section 31AP(4A) or paragraph (a) or (c) of section 31AP(9) applies to a matter to which this section relates, then the Minister shall issue a direction accordingly. (17) The direction issued by the Minister under subsection (16) is deemed to have immediate effect and its terms are considered to be incorporated into the plan, or, if appropriate, to constitute the plan. …” The domino effect 29. As Holland J. recalled in the introduction to his judgment, PDA 2000 has variously been described – even before the introduction of the OPR – as notoriously complex, a statutory maze, and as confusing almost to the point of being impenetrable. The interposition of the OPR introduced a new thicket into the statutory maze but on the case as argued – and as decided by the High Court – it is not necessary to work through it all. 30. Cork County Council v. Minister for Housing [2021] IEHC 683 was an application by way of judicial review for an order of certiorari of a direction issued by the Minister under s. 31AN PDA 2000 in which – as in this case – the applicant challenged each of the steps taken by the OPR and the Minister leading to the direction. Humphreys J. described the recommendation issued by the OPR to the Minister under s. 31AM(8) as the first critical legal step in the process and as the first domino which, if it fell, would bring down the remaining dominoes. In the case at hand, the parties were agreed that if the opinion of the OPR subtending the first notice was invalid, the remainder of the notices would fall with it. The engagement between the OPR and DLRCC 31. The first step in the consultation process between DLRCC and the OPR was the assessment by the OPR (in accordance with s. 32AM(1)(a)) of an Issues Paper for the Dún Laoghaire-Rathdown County Development Plan 2022 – 2028. In a letter of 28th February, 2020 the OPR drew attention to the policy objectives of the National Planning Framework (“NPF”) and Regional Spatial and Economic Strategy (“RSES”) to secure more sustainable and compact urban development patterns, with specific targets for the delivery of new homes on infill and brownfield sites within urban areas. It referenced in particular National Policy Objective (“NPO”) 3b which set a target that at least 50% of all new homes targeted for Dublin City and suburbs would be delivered within existing built-up footprint. The OPR suggested that DLRCC should reconsider the then proposed “0/0 Zone” which provided that no increase in the number of buildings would normally be permitted. 32. In its assessment dated 16th April, 2021 of the draft plan – as it did on all of its later communications with DLRCC – the OPR noted that one of the key functions of that office was the strategic evaluation and assessment of the plan to ensure consistency with legislative and policy requirements relating to planning. The OPR had – it said – evaluated and assessed the draft plan under the provisions of ss. 31AM(1) and (2) of the PDA 2000; and it issued a number of recommendations which – it said – related to clear breaches of the relevant legislative provisions of the national or regional policy framework and/or the policy of Government as set out in Ministerial guidelines under section 28. DLRCC – it was said – was required to implement or address the recommendations in order to ensure consistency with the relevant policy and legislative provisions. 33. At para. 4, the OPR recommended that having regard to the national and regional policy objectives to implement compact growth within Dublin city and suburbs, including NPO 3b and RPO 3.2, and to the Sustainable Residential Development Guidelines which provide for increased residential density along public transport corridors, including in the interest of maximising the return on public transport investment, the planning authority was required to omit the 0/0 Zone objective from the plan as an unnecessary restriction on sustainable development. 34. DLRCC responded by way of a formal notice of 17th November, 2021 in accordance with s. 12(5)(aa) PDA 2000 which referenced the Chief Executive’s report and annexed the response of the elected members. 35. The Chief Executive – following the recommendation of the OPR – had recommended the omission of the 0/0 zones and the inclusion of a new Specific Local Objective (“SLO”) to ensure that development in the relevant areas (i) did not have a significant negative impact on the environmental sensitivities in the area, and (ii) did not significantly detract from the character of the area either visually or by generating traffic volumes which would necessitate road widening or other significant “improvements”. The elected members, while content to adopt the proposed new SLO, had declined to omit the 0/0 zoning and on 12th October, 2021 had resolved:- “… in the best interests of maintaining the highest level of protection to sensitive high amenity areas, to retain the 0/0 zoning as set out in the Draft Plan and to insert the recommended SLO as set out on page 65 of the Chief Executive’s Report.” 36. The reasons given by the elected members for not complying with the recommendation were said to have included that:- • There is a clear conflict between the 0/0 objective which looks to protect the area and the national objective to increase densities. • Planning Authority would uphold the new SLO bit [recte. but] cannot imagine that [An Bord Pleanála] would uphold the SLO over Regional and National Policy. • Ministerial Circular from September 2021 (NRUP 02/2021) remarks that ‘towns and their contexts are clearly not all the same, and planning policy and guidance are intended to facilitate proportionate and tailored approaches to residential development’. • Therefore, it is reasonable to require the highest level of protection to a very small area. • Current Plan has not protected the area. • Useful to retain the 0/0 objective. 37. There were no agreed minutes of the members’ meeting but the written response suggested that the full narrative of the reasons given by the elected members would be apparent from the webcast of the meeting. 38. The OPR replied to DLRCC on 24th December, 2021. It recalled that as had been outlined in the OPR’s submission on the draft Plan, “the Office considered the draft Plan to be generally consistent with policies in the National Planning Framework (NPF) and the Regional and Spatial Strategy (RSES) … and recommended changes to enhance its alignment with national and regional policies in the aforementioned, and for consistency with [various identified Ministerial guidelines].” Under the “Key theme” of “Core strategy and zoning for residential use” it was said that:- “The Office is therefore generally satisfied that the Core Strategy is consistent with the recommendations of the Office, as submitted by the planning authority in its section 12(5)(aa) notice.” 39. In parsing the exchange of notices and correspondence between the OPR and DLRCC – which appears to have run to 828 pages, of which 547 pages were winnowed out to make up the book of agreed exhibits – counsel for Mount Salus relied on the OPR’s statements of general satisfaction and alignment as inconsistent with its case that the Development Plan did not meet the requirements of s. 10(1A) but it seems to me that this would be to take what was said out of context. In the same letter of 24th December, 2021 the OPR noted the decision of the members not to accept the recommendation of the Chief Executive to omit the 0/0 zoning objective in accordance with the OPR’s recommendation “notwithstanding the CE’s concurrent recommendation to include a rational and appropriate safeguard for this sensitive area under SLO 130 (MA 296)” and went on to recall that its recommendation had advised that the 0/0 zoning objective was inconsistent with national and regional policy objectives to implement compact growth, including NPO 3b and RPO 3.2 and to the Sustainable Residential Development Guidelines (2009) which provided for increased residential density along public transport corridors, including in the interest of maximising the return on public transport investment. To my mind, any reasonable reader of this letter could have been in no doubt but that the OPR had not changed its mind. What is, however, clear is that the OPR was focussing on two policy objectives and on particular areas of the county. 40. I pause here to say that the Sustainable Residential Development Guidelines referred to in the OPR’s requirement that the 0/0 zoning be omitted were – as elsewhere identified in the OPR’s letter – the Guidelines for Planning Authorities on Sustainable Residential Development in Urban Areas (2009), which were issued by the Minister for Environment, Heritage and Local Government under s. 28 PDA 2000. As spelled out in s. 28 PDA 2000 as well as the Guidelines themselves, those were guidelines which planning authorities were required to have regard to. As explained by Humphreys J. in a judgment delivered on 5th November, 2021 in Cork County Council v. The Minister for Housing [2021] IEHC 683, the OPR’s reliance on s. 28 guidelines was misplaced: but as the trial judge noted, no relief was sought in these proceedings on the basis of what he described as that flawed reliance in the early stages of the process. 41. In its letters of 16th April, 2021 and 24th December, 2021 the OPR identified in the 2009 Guidelines the need for land use planning to underpin the efficiency of public transport services by sustainable settlement patterns, including higher densities, on lands within existing or planned transport corridors in order to maximise the return on public transport investment. 42. The judge, at para. 115, noted that the impugned Ministerial direction invoked housing development along public transport corridors and considered where, elsewhere than in the 2009 Guidelines, the Minister might properly have derived his reliance on a policy of compact dense development along transport corridors. For the reasons given, the judge concluded at para. 136 – albeit, he said, somewhat hesitantly – that NPO 3b should be interpreted as encompassing espousal of compact development along transport corridors: and there is no cross-appeal against that finding. 43. The Dún Laoghaire-Rathdown County Development Plan 2022 – 2028 was made by the elected members of the Council on 10th March, 2022. 44. It identified at para. 4.3.1.1 that:- “Notable Character Area Exclusions There are significant parts of Dalkey and Killiney characterised by low density development. Some of these areas have been identified as areas where no increase in the number of residential buildings will normally be permitted (i.e. the ‘0/0’ zone). However, much of this area lies close to the DART line where higher densities would, in normal circumstances, be encouraged. Sensitive infill development will, however, be considered on suitable sites as determined by the Planning Authority. Such sites should: • Be located within a 10 minute walk of a DART station … • Development shall not detract from the unique character of the area either visually or by generating traffic volumes which would necessitate road widening or other significant improvements (refer also to Section 12.3.7.8).” 45. At para. 12.3.7.8 it was provided that:- “12.3.7.8 0/0 Zone Locations have been identified on the Development Plan maps where no increase in the number of buildings will normally be permitted. Such locations include areas in the vicinity of the coastline, where density controls are considered appropriate in the interests of preserving their special amenity. Many of these locations are however, within close proximity of the DART line where higher densities would normally be permitted and promoted. Small scale, sensitive infill development may be considered in these areas on suitable sites where such development would not detract from the character of the area either visually or by generating traffic volumes that would cause potential congestion issues which would, in turn, necessitate road widening or other significant improvements. Aspects such as site coverage and proximity to boundaries, impacts on drainage, loss of landscaping, the existing pattern of developments, density and excavation impacts will also be critically assessed in determining applications for residential development in the 0/0 Zone.” 46. On 21st March, 2022 DLRCC, in accordance with the requirements of s. 31AM(6) PDA 2000, gave formal notice to the OPR of the making of the Development Plan and of its non-compliance with the OPR recommendation that the 0/0 zoning be omitted. The appended Overview of Compliance with OPR Recommendations on the DLR County Development Plan 2022 – 2028 repeated the reasons given by the elected members which had been set out in the s. 12(5)(aa) notice of 17th November, 2021. The impugned measures 47. The first of the impugned measures is the Notice Pursuant to section 31AM(8) of the Planning and Development Act 2000 (as amended) dated 6th April, 2022 issued by the OPR to the Minister. The notice set out that, having considered the Development Plan, the OPR was of the opinion that:- “a) the Development Plan has not been made in a manner consistent with the recommendations of the Office, which required specific changes to the Development Plan to ensure consistency with the NPO 3b of the National Planning Framework (NPF), with RPO 3.2 of the RSES, … Specifically the Development Plan: i. includes a 0/0 zone objective and associated provisions for significant parts of Killiney and Dalkey where no increase in the number of buildings will normally be permitted, thereby restricting infill development and increased residential density along the DART railway corridor over and above restrictions that are reasonably applied to protect the heritage, character and amenity of the county; … b) the Development Plan has not been made in a manner consistent with recommendations of the Office, which required specific changes to the Development Plan to ensure consistency with national policy objectives (NPOs) of Project Ireland 2040, National Planning Framework (the NPF) and the reginal policy objectives (RPOs) of the Eastern and Midland Regional Assembly Regional Spatial and Economic Strategy (the RSES), … c) as a consequence of the above matters, the development plan made by Dún Laoghaire-Rathdown County Council (‘the Council’) fails to set out an overall strategy for the proper planning and sustainable development of the area concerned, contrary to the requirements of Section 10(1) of the Act; and d) the use by you of your function to issue a direction under section 31 of the Act would be merited.” 48. Over nine pages, the OPR set out the background to the notice; the relevant passages from the Development Plan; the recommendation which it had made for the omission of the 0/0 Zone objective; its engagement with the Chief Executive and the elected members, before concluding that:- “… the Office considers that the heritage and amenity of these parts of Killiney and Dalkey are fully protected by the aforementioned objectives within the Development Plan and the limitations on further residential development by way of the 0/0 zone objective is not necessary to meet the elected member’s (sic.) stated purpose and is unreasonably restrictive. The objectives of the Development Plan are therefore not consistent with national (NPO 3b, 11, and 35 of the NPF) and regional (RPO 3.2 and 4.3 of the RSES) policy, contrary to section 10(1A) 0f the 2000 Act. The objective would undermine the Development Plan core strategy and other objectives that promote compact and sustainable growth (Objectives CS22, PHP18, and T1 of the Development Plan).” 49. The excusive focus of the OPR’s recommendation was on the 0/0 zoning of the relevant areas of Killiney and Dalkey and the DART railway corridor. The recommendation, and the opinion on which it was based, did not take account of the development plan elsewhere in the area of the development plan or the other two major public transport corridors along the N 11 road and the Luas tramway. The authorities 50. On the appeal to this Court – as they had in the High Court – counsel referred to a number of authorities. Three of them were central to the conclusion of the High Court judge and to the core arguments on the appeal. 51. The first of the trilogy of cases is Tristor Ltd. v. Minister for the Environment [2010] IEHC 397. That was a challenge by way of judicial review to a direction issued by the Minister to a planning authority – incidentally, it was DLRCC – in exercise of the powers conferred by s. 31 PDA 2000 as originally enacted. The interposition of the OPR in the meantime has significantly added to the procedural complexity of Ministerial review of a development plan but the nature of the review and – as the old cases would have put it – the mischief to which the power is directed have not changed. The power was and is directed to the legality of the development plan under consideration; as opposed to the proper planning and sustainable development of the planning area. It was agreed in the High Court and on the appeal that notwithstanding the added layers of the involvement of the OPR, Tristor is still good law. 52. Tristor was the owner of lands at The Park, Carrickmines, which the elected members of the Council had voted should be designated as a district centre for retail purposes. The Minister took the view that this did not accord with a Retail Strategy for the Greater Dublin Area as prepared by the Dublin and Mid-East Regional Authorities; would be likely to adversely impact on existing and proposed town centres in the development plan area; and would be likely to exacerbate traffic issues in and around the designated area: and he directed the Council to delete the designation. Tristor challenged the validity of the direction. 53. Section 31 PDA 2000 as originally enacted made provision for Ministerial intervention in case of a draft development plan – s. 31(1) – and a development plan – section 31(2). Section 31(2) provided that:- “Where the Minister considers that any development plan fails to set out an overall strategy for the proper planning and sustainable development of the area of a planning authority or otherwise significantly fails to comply with this Act, the Minister may, for stated reasons, direct the authority to take such specified measures, as he or she may require to review or vary the development plan to ensure compliance with this Act and the authority shall comply with any such direction.” 54. In s. 31 PDA 2000 as enacted, the pre-condition to Ministerial intervention was that he or she should “consider” that a development plan or a draft development plan “fails to set out an overall strategy for the proper planning and sustainable development of the area of a planning authority.” And the object of any intervention was “to ensure … compliance with this Act.” The core pre-condition to intervention by the OPR in s. 31AM(8)(b) is the same: the OPR must be “of the opinion” that a decision by a planning authority not to comply with a recommendation “results in the making of a development plan … in a manner that fails to set out an overall strategy for the proper planning and sustainable development of the area concerned.” I see no difference between the original requirement that the Minister should “consider” that his intervention was warranted and the requirement that the OPR should be “of the opinion” that its intervention is warranted. The ultimate object of the exercise is to “ensure that the development plan … sets out an overall strategy for proper planning and sustainable development”, which is what is required by section 10(1). Thus Tristor continues to provide guidance for the examination of the nature of the power conferred on the OPR. 55. In Tristor the first issue addressed by Clarke J. (as he then was) was the standard of review by reference to which the direction was to be judged by the court. Tristor had argued that the decision by the Minister to exercise the power in s. 31(1) was a decision that the planning authority had in fact failed to set out an overall strategy for the proper planning and sustainable development of the area. Clarke J., however, found that the use of the word “considers” in s. 31(1) was decisive. The section did not require that there should have been a breach of the Act; rather that the Minister should consider that there had been a breach of the Act. The court found that the standard of review was the ordinary judicial review standard. 56. The power of the Minister in s. 31(1) PDA 2000 as amended, and the power of the OPR in s. 31AM(8) PDA 2000, arises when he or she or it is “of the opinion” – as opposed to “considers” – that there has been a failure on the part of the planning authority but it was not contended by Mount Salus that this had any effect on the standard of review as laid down in Tristor for the earlier iteration of the power. Nor, indeed, was it submitted that this Court should reconsider the approach laid down in Tristor. As the Minister’s power in s. 31(1) is based on his opinion, so also the power conferred on the OPR by s. 31AM(8) to issue a recommendation to the Minister is based on its opinion. 57. It seems to me that the interpretation of the power conferred on the Minister by s. 31(1) is, if anything, reinforced by the legislative scheme for the interposition of the OPR. The power and obligation conferred and imposed on the OPR by s. 31AM(8) to issue a recommendation to the Minister derives from its opinion first, that the development plan has not been made in a manner consistent with its recommendations; secondly, that the development plan has been made in a manner which fails to set out an overall strategy for the proper planning and sustainable development of the area concerned; and thirdly, that the use by the Minister of his or her functions to issue a direction under s. 31 would be merited. That these are all matters of opinion rather than determination is underlined by the requirement in s. 31AN(1) that the Minister must consider the recommendations of the OPR: which he may or may not agree with. Before exercising the power conferred by s. 31(1) the Minister must be of the opinion that the planning authority and the development plan have failed in the respects there set out. The focus of the Minister’s consideration is on the plan rather than the opinion of the OPR on which the s. 31AM notice is based. The Minister is not immediately concerned with whether the opinion of the OPR was correct or incorrect but is to form his own opinion as to the several questions set out. 58. Returning to Tristor, Clarke J. found at para. 5.4 that:- “… on the plain wording of the Act, the Minister is entitled to form a view (within the bounds of the section) that the conditions necessary for the exercise of a discretion under s. 31 exist. That ministerial view is, of course, subject to judicial review. In coming to that view the Minister must take into account all proper factors and exclude from his consideration any factors which are irrelevant. In addition, the view which the Minister ultimately forms must be rationally based on the materials available to the Minister at the time. However, subject to those limitations the Minister is entitled to come to a view, and if he does so, then it can properly be said that he ‘considers’ that a relevant failure of compliance has occurred such as entitles the Minister to exercise his jurisdiction under the section.” 59. In this case, Holland J. considered in some detail a line of authority grouped together under the heading “of the opinion” caselaw but, with respect, I am not sure that this really added much. The State (Lynch) v. Cooney [1982] I.R.337 established, and the later cases identified by the judge affirmed, that the Minister’s opinion must be bona fide held, factually sustainable, and not unreasonable. In the same way that there is no material difference between a decision maker being “of the opinion” and being “satisfied”, I see no difference between the requirement in the original s. 31 that the Minister “considers” and the current formulation that he – or the OPR, as the case may be – should be “of the opinion” that a development plan fails to set out an overall strategy. More to the point for present purposes, however – as Clarke J. pointed out in Tristor – the OPR must take into account all proper factors and exclude from its consideration any factors which are irrelevant. To be able to do that, the OPR must first of all correctly identify the power and – as Clarke J. said in Tristor and Holland J. said in this case – ask itself the right question. 60. In Friends of the Irish Environment v. Minister for Housing [2024] IEHC 588, Humphreys J. identified the central holding in Tristor as being that s. 31 as it then stood did not confer an entitlement on the Minister simply to disagree with the strategy contained in a development plan, recalling that Clarke J. said that:- “… provided there is a strategy set out, and that it is reasonably described as an overall strategy for the proper planning and sustainable development of the relevant area, then it does not seem to me that the Minister is entitled to impose an alternative strategy simply because the Minister may prefer it.” 61. In the course of oral argument on the present appeal, counsel for the Minister and the OPR had a good deal to say about evaluative planning judgment but, with respect, it seems to me that this obscured rather than clarified the question. I do not disagree that the opinions on which first the OPR and then the Minister were entitled to act could be characterised as matters of evaluative planning judgment, but the evaluation must be whether the development plan set out an overall strategy for the proper planning and sustainable development of the relevant area and otherwise complied with the requirements of the Act, and not whether an alternative or different or modified strategy would have been better. 62. The second – in time – in what I regard as the trilogy of centrally important authorities is the judgment of the Supreme Court in Killegland Estates Ltd. v. Meath County Council [2023] IESC 39. 63. Killegland was a case in which a site of 0.84 ha previously zoned for residential development – and bought by the applicant at a price which reflected that zoning – was rezoned for community infrastructure. One element of the landowner’s challenge to the rezoning was that it was said to have been inconsistent with the NPF and RSES, specifically NPO 3c and RPO 3.2. This, it was contended, breached the provisions of ss. 10(1A), 12(10) and 12(18) PDA 2000. 64. I pause here to say that NPO 3c is materially identical to NPO 3b. The obligation in s. 12(18) of to ensure consistency with the national and regional objectives specified in the National Planning Framework and the regional spatial and economic strategy more or less mirrors the requirement in section 10(1A). I say more or less mirrors because of the presence in s.12(18) and absence from s. 10(1A) of the definitive article. Section 12(18)(a)(i) refers to “the national and regional development objectives” specified in the NPF and RSES, while s. 10(1A) refers to “national and regional development objectives.” There was some debate in the High Court and on the appeal as to the significance – if any – to be attached to the omission in s. 10(1A) of the definite article. I will come to this in due course but at the risk of spoiling the plot, I do not believe that it is a matter of any significance. 65. Starting at para. 100, Hogan J. (for a unanimous Supreme Court) considered generally the requirements of the NPF:- “100. Before considering any of the statutory provisions in detail or the potential impact of the NPF, it is worth observing – as Humphreys J. did (at paragraph 125) – that the overall effect of these provisions is to constrain to some degree the Council and the elected members so far as the making of development plans are concerned. Some allowance must, of course, be made for the large scale nature of this exercise and it would be unrealistic to expect perfect consistency or alignment with national planning guidelines or frameworks such as the NPF. The elected members are, nonetheless, not at large, and any such development [plan?] must align itself at least in general with certain national and local policy objectives. In Highlands Residents Association v. An Bord Pleanála [2020] IEHC 622, McDonald J. made comments to similar effect when he remarked (at para. 39) that the provisions of s. 10(1A) of the 2000 Act were ‘clearly designed to ensure that the development objectives in a development plan are consistent, as far as practicable, with national and regional development objectives.’ 101. In many ways the key question so far as this appeal is concerned is the extent to which the operation of the NPF is intended to be prescriptive. On this point, Killegland maintains, in essence, that this aspect of the development plan is not consistent with the objectives of the NPF, principally because this this 0.8ha site is located right in the heart of Ashbourne and is a classic in-fill site of the kind deemed suitable for housing and residential development by objective 3c of the NPF. If objective 3c had been made the equivalent of a mandatory statutory obligation so that it required every in-fill site of this kind to be zoned suitable for housing, then the applicant’s case would have much to commend it. 102. Where I respectfully part company with the arguments advanced by Killegland on this point is that I do not consider that one can read either the relevant statutory provisions – particularly s. 12(18) – or the objectives of the NPF in this way. In the first instance, s. 12(18) simply requires that the development plan is ‘consistent’ with the ‘objectives’ of the NPF. Like Humphreys J., I read this language as meaning consistent generally, as distinct from complying in every detailed and minor particular. The language of objective 3c is moreover generally precatory (‘…a preferred approach…’) rather than imposing a legally prescriptive standard which required every available in-fill site to be zoned for housing. This is further reflected in section 4.5 of the NPF which, as we have seen, speaks of a ‘target’ of a ‘significant proportion of future urban development on infill/brownfield development sites’ within existing settlements. 103. All of this again suggests that the NPF is in this respect as I have just said largely precatory and aspirational. It might well have been different if the development plan had shown a casual disregard throughout the county of the need to encourage in-fill development on brownfield and other sites immediately contiguous to the core areas of each urban settlement, but that particular case has never been advanced. As Humphreys J. also observed (at paragraph 146), one must also have regard to the fact that by contrast to the language of s. 12(18) the Oireachtas used mandatory and prescriptive language in other parts of closely related sections. Thus, for example, as we have already noted, s. 10(2A)(a) provides that a core strategy ‘shall’ contain sufficient information to show that development plans are ‘consistent’ with the NPF. The obligation to provide the information is thereby made mandatory (“shall”), but a more accommodating standard (‘consistent’) is provided in relation to the actual contents of the development plan itself.” 66. In the case at hand, the pockets of land in Killiney and Dalkey covered by the 0/0 zoning were clearly not individual sites and were vastly greater than 0.84 ha, but it seems to me that the principle is the same. The requirement is for general consistency. I would perhaps go a little further than Hogan J. and would say that it would be not only unrealistic but impossible to achieve perfect consistency or alignment throughout a development plan area with what, after all, are the competing requirements of the national planning guidelines and frameworks. The statutory requirement in s. 10(1A) PDA 2000 is expressly and necessarily limited to consistency “as far as practicable.” 67. Killegland is clear authority for the proposition that NPO 3c does not require that every in-fill site which is suitable for housing must be zoned for housing. The judgment of Hogan J. – like every other judgment – must be read in the context in which it was written. I do not understand the observation of Hogan J. that the view he took of Killegland’s argument might have been different if the development plan had shown a causal disregard throughout the county of the need to encourage in-fill development as requiring the OPR, or the Minister, to be of the opinion – or as requiring an applicant for judicial review to show – that a development plan has shown a casual disregard throughout the county of a national policy objective. It is, however, authority for the proposition that the National Planning Framework does not require that every in-fill site which is suitable for housing must be zoned with that objective. It is also, I think, authority for the proposition that the consistency of the development objectives under consideration in that case – NPO 3c and RPO 3.2 – in a development plan, cannot be perfect but must be assessed in the round. 68. The third case in the trilogy is Friends of the Irish Environment v. Minister for Housing [2024] IEHC 588 and [2025] IECA 128. 69. Friends of the Irish Environment was a challenge by an environmental NGO to a direction by the Minister – on a recommendation by the OPR – to Fingal County Council to remove certain text from the Fingal County Development Plan 2023 – 2029 relating to noise insulation schemes operated by the Dublin Airport Authority. The application to the High Court and the appeal raised a number of issues, including whether the Minister was entitled to have formed the opinion that the relevant provisions of the development plan were not in conformity with NPO 65 of the NPF. 70. The objective of NPO 65 was to:- “Promote the proactive management of noise where it is likely to have significant adverse impacts on health and quality of life and support the aims of the Environmental Noise Regulations through national planning guidance and noise action plans.” 71. In 2019 Fingal County Council – by its chief executive, in whom the statutory power to do so was vested – made the Dublin Airport Noise Action Plan 2019 – 2023, the key objective of which was:- “… to avoid, prevent and reduce, where necessary, on a prioritised basis the effects due to long term exposure to aircraft noise, including health and quality of life through implementation of the International Civil Aviation Organization’s ‘Balanced Approach’ to the management of aircraft noise as set out under EU Regulation 598/2014.” 72. Without getting bogged down in the complicated detail, part of the noise action plan was a residential noise insulation scheme which was to be made available to householders within a predicted 63 dB LAeq 16-hour contour of Dublin airport. The elected members of the Council wanted a lower threshold of 40 dB, and to that end wrote into the development plan an objective to take measures including by the expansion of the noise insulation schemes operated by DAA to include all areas exposed to 40 dB Lnight or higher. Humphreys J. found – and this Court affirmed – that the requirement in NPO 65 to support the environmental noise regulations through noise action plans itself had the consequence of supporting the Dublin Airport NAP and that it was reasonably open to the OPR and the Minister to conclude that the inclusion in the development plan of an objective to take measures that were premised on the inadequacy of the existing noise mitigation measures was not consistent with the requirement to support the environmental noise regulation through noise action plans as embodied in NPO 65. In other words, the elected members’ objective to manage aircraft noise by the development plan cut across the national policy objective that it should be managed by a noise action plan. 73. The elected members had also sought to arrogate to themselves a function which had been conferred by law on the chief executive. 74. In this case, Friends of the Irish Environment is relied on by the Minister and the OPR in support of their argument that the assessment of the compliance of a development plan with national policy objectives need not be by reference to the entire development plan area. On the facts, the amendments to the Fingal County Development Plan made by the elected members were directed to the environs of Dublin airport, but so was the policy objective: which was to manage airport noise and support the aims of the Environmental Noise Regulation by adopting and implementing noise action plans. The provisions of the development plan targeted by the OPR and the Minister did not amount to “casual disregard” of the national policy objective but demonstrated wilful disobedience. There was no question of reconciling apparently competing national objectives, or of a difference of opinion as to how consistency with the national objective might have been achieved. The High Court judgment 75. In the summary of his conclusion at para. 328, Holland J. found that the opinion of both the OPR and the Minister that – in breach of s. 10(1) PDA 2000 – the DLRCC Development Plan failed to set out an overall strategy for the proper planning and sustainable development of the area, was in turn based on their opinion that – in breach of s. 10(1A) – the development plan objectives were not consistent, as far as practicable, with NPO 3b, NPO 11 and NPO 35, and RPO 3.2 and RPO 4.3 That much is evident from the notices and recommendations. 76. The judge went on to find that the OPR and the Minister had misdirected themselves in law as to the basis on which and the standard by which such consistency must be judged. They failed – he found – to judge consistency by reference to the criteria of general consistency and by reference to the entire development plan area and the entire of the transport corridors in the development plan area. In that – he said – they failed to ask themselves the right question. 77. Holland J. said that he would, accordingly, declare the decision of the OPR to issue its s. 31AM notice invalid by reason of misdirection of law. It followed – he said – given the domino effect, that the Minister’s decision to issue the impugned direction was invalid. In any event – he said – the error of law subtending the OPR’s recommendation also permeated the Minister’s direction and, on that basis also, the direction was invalid. The appeals 78. The Minister and the OPR each appealed separately against the judgment and order of the High Court. Each named the other as a respondent to the appeal, and both filed respondent’s notices supporting the appeal of the other. The appeals were opposed by Mount Salus. Neither Ms. Smyth nor DLRCC participated in the appeals. 79. The Minister’s grounds of appeal ran to thirteen paragraphs and the OPR’s to sixteen paragraphs but the grounds were in substance the same and in many instances identical. 80. Although the judgment of the High Court examined all of the arguments which had been advanced by the parties, the ratio was narrow. 81. It will be recalled that the applicant’s Core Ground No. 6 – on which the challenge to the impugned measures was based – was that the Minister and the OPR exceeded the powers conferred on them by ss. 31, 31AM and 31AN of PDA 2000; and were inadequately reasoned, unreasonable, irrational, and therefore invalid. The conclusion of the High Court was directed to the nature and extent of the statutory powers, and not the reasonableness or rationality of the decisions. 82. As I will come to, the High Court judge, in his analysis and reasoning, drew heavily on Killegland. That was a judgment which post-dated the filing of the statement of grounds but pre-dated the hearing in the High Court and objection was taken in the High Court that the ground had not been laid in the pleadings for the argument which Mount Salus sought to make in reliance on Killegland. Holland J. found that the pleading was sufficient and while one of the OPR’s grounds of appeal challenged the correctness of that finding, it was not pursued. The basis on which the OPR and the Minister were entitled to form an opinion 83. The first ground of appeal on behalf of the Minister is that the judge erred in holding that the Minister was entitled to make a direction under s. 31(1)(ba) only where he was satisfied that the decision of DLRCC was irrational, in the judicial review sense. In doing so – it is said – the judge misinterpreted and significantly narrowed the scope of discretion under section 31(1)(ba). 84. The first ground of appeal on behalf of the OPR suggests – in a roundabout way – that the High Court wrongly concluded that s. 31AM(8) PDA 2000 required that it should apply “what is effectively an irrationality standard vis-à-vis the planning authority.” Not the least difficulty with this ground is that the OPR’s notice of appeal acknowledges, at para. 14, that the High Court judge “expressly did not decide the case of irrationality or inadequate reasons as pleaded by the applicant”. 85. It seems to me that it was first the OPR and later the Minister who set the bar by asserting, as part of their reasons, that the 0/0 zoning was not necessary to meet the elected members’ stated purpose and unreasonably restrictive, to which the Minister later added that it was disproportionate. In other words, it was the OPR and the Minister who had introduced the concept of irrationality. Mount Salus seized on this to challenge opinions of the OPR and the Minister as being themselves irrational so that – as the judge put it – the question became whether the OPR and the Minister had acted irrationally in deciding that the elected members’ decision not to accept the recommendation was irrational. 86. The Minister’s grounds of appeal reference several passages in the High Court judgment but notably not para. 318 – which is, however, referenced in the OPR’s grounds – in which the judge indicated that it was unnecessary to decide what he described as the rationality issue, before – as he put it – sketching out obiter some relevant considerations without deciding them. 87. In seeking, at para. 320, to distil or define the irrationality issue, the judge recalled that the Minister’s decision was that the 0/0 objective was ‘not reasonable” and “disproportionate” – in other words, he said, irrational – and on that basis unlawful so as to properly ground a s. 31 direction. So, he said, the question became whether the Minister was irrational in deciding that the elected members were irrational: a difficult and delicate question, even in conceptual terms. Both before and after saying what he said about irrationality and reasons, the judge made it quite clear that he was not deciding the issue. 88. It follows, contrary to the Minister’s apprehension, that the judge did not decide that in principle the power to issue a direction arose only where he was satisfied that the decision of the planning authority was irrational; or, as the OPR would put it, that s. 38AM(8) required that it should apply an irrationality standard vis-à-vis the planning authority. As unequivocally spelled out at para. 310 of the judgment, and again in the summary of his conclusions at para. 328, the finding of the judge was that the Minister and the OPR had erred in law in their failure to correctly interpret the national and regional policy objectives, as required by Killegland. The role of the Minister in policy formulation 89. The third of the Minister’s grounds of appeal – reflected in the OPR’s second ground – is that the judge erred in law in assuming that the Minister has no role to play in policy formulation in the context of development plans; and that the policy decisions with respect to whether the objectives of a development plan are consistent with the objectives of the NPF and/or the RSES have been entrusted to the Council to the exclusion of the Minister and the OPR. 90. With respect, I find this very confused. With no disrespect to counsel, it is not what the judge said. 91. At the hearing of appeal, as it was in the High Court, it was common case that the role of the Minister in s. 31AN and s. 31 (as well as of the OPR in s. 31AM) is – as Humphreys J. put it in Friends of the Irish Environment v. Minister for Housing [2024] IEHC 588 – that of law enforcers and not law givers. It seems to me that the supervisory role of the Minister in s. 31 is underscored by the interposition of the OPR. It is not, I think, a role in policy formulation and it is confusing to think of the function – as the Minister submits – as “a role in the making of the development plan”. It is more accurately identified in the Minister’s fourth ground of appeal – and in the OPR’s second ground – as a “supervisory function” to ensure that development plans comply with the PDA. 92. Holland J., at para. 10 of his judgment, set out his understanding of the Minister’s position as to the legal regime governing his power to direct planning authorities as to the content of their development plans. On the appeal, it was not suggested that the judge misunderstood the Minister’s position. 93. The Minister’s position so set out was first, that s. 10(1) PDA 2000 requires that development plans set out an overall strategy for the proper planning and sustainable development of the area to which it applies. That is what the section says. To qualify as a proper and lawful such strategy, the overall strategy must comply with the mandatory requirements of s. 10 PDA. Secondly, the Minister’s position was that by s. 10(1A) development plans must set out a core strategy which shows that the development objectives of the development plan are consistent as far as practicable with development objectives set out in the NPF and applicable RSES. Again, that is what the section says. Thirdly, in making development plans, the elected members of planning authorities are statutorily obliged to ensure that they are so consistent. That cannot be gainsaid. Fourthly, PDA 2000 vests the assessment whether the plan is so consistent initially in the elected members but thereafter in the OPR and ultimately – by s. 31(1)(ba) – in the Minister. Fifthly, the Minister in making his assessment of consistency is entitled to form his opinion as a matter of evaluative planning judgment. Sixthly, if the Minister forms the opinion that the development plan is consistent with the NPF and RSES development objectives, he is not entitled to impose, by direction to the planning authority, his own planning judgment as to the preferred means of consistency with such objectives. Seventhly, if the Minister forms the opinion that a development plan is not consistent as far as practicable with NPF and RSES objectives, in breach of s. 10(1A), he may issue a ministerial direction accordingly, requiring, as to any such inconsistency, correction of the development plan. Eighthly, if the Minister forms the opinion that a development plan is inconsistent with NPF and RSES development objectives in breach of s. 10(1A), then he may also form the opinion that it fails to set out an overall strategy in breach of s. 10(1) and may issue a ministerial direction accordingly requiring correction of the development plan. Lastly, such a ministerial direction as to inconsistency with NPF or RSES development objectives and the absence accordingly of an overall strategy for the proper planning and sustainable development of the area issued under s. 31 is judicially reviewable as to its merits, only for rationality. 94. Having set out at para. 10, sub-paras. (i) to (ix) his understanding of the Minister’s position, Holland J. went on to find at para. 11 that:- “It follows that, as inconsistency of a development plan with NFP and RSES development objectives is illegal as in breach of s. 10(1A), the Minister’s position was that the validity of a ministerial direction based on evaluative planning judgment finding such inconsistency depends on the existence of a ministerial opinion that the development plan was tainted by illegality. As Humphries J. said in FoIE, the OPR and the Minister are, in his respect, law enforcers and not law givers.” 95. Elsewhere in PDA 2000 the Minister undoubtedly has a role to play in policy formulation, but it is common case that in the exercise of his power in s. 31 (on a referral by the OPR in accordance with s. 31AM) he is concerned with the implementation rather than the making of policy. The opinion that must be formed by the Minister – and before the Minister by the OPR – is an opinion that the plan made by the planning authority is inconsistent with the national or regional policy objectives and, in consequence, illegal. The statutory scheme is that the development plan is made by the elected members and, in the first instance, the determination as to whether the objectives of the development plan are consistent with the national and regional objectives is entrusted to the Council. The judge – it is said – assumed that “the policy decisions with respect to whether the objectives of a development plan are consistent with the objectives of the NPF and/or the RSES have been entrusted to the Council to the exclusion of the Minister and the OPR”. This suggested assumption, however, is not what the judge said. It seems to me that the proposition that the decision as to consistency is a policy decision supposes that the OPR and the Minister are entitled to intervene in the formulation of the development plan, as opposed to assessing consistency. 96. In the end, I do not understand the Minister to have attempted to resile from the position he took in the High Court: that his role in s. 31 – and that of the OPR in s. 31AM – is as a law enforcer and not a law giver, but it is at best unhelpful to characterise the exercise of what is acknowledged to be a supervisory function as policy formulation or a policy decision. 97. The Minister’s third ground of appeal goes on to suggest that the judge, in doing what he was supposed to have done – wrongly, for the reasons I have given – ignored the fact that “in the context of section 31 of the Planning Act, the Minister, who himself has a democratic mandate, has been expressly conferred with a role in the making of the Development Plan by the legislature, and in particular has been conferred with the role of finally determining, on the recommendation of the OPR, whether the objectives of a Development Plan are consistent with the objectives of the NPF and/or the RSES.” 98. Again, with respect, I believe that this is confused. There is no doubt that the Minister has a democratic mandate. There is no doubt that the Minister has been conferred with the role of finally determining, on a recommendation of the OPR, whether the objectives of the development plan and consistent with the national and regional objectives. The imprecision is in the characterisation of the Minister’s role under s. 31 as a role in the making of the plan. It is true that the purpose of the power is to ensure that the objectives of the plan are consistent with the national and regional objectives, and to that extent to ensure that the plan is made in accordance with law, but the role is not a role in the striking of the balance but to ensure that a balance has been struck. Significantly, it seems to me that the Minister’s emphasis on his democratic mandate fails to take account of the fact that he can only act on a recommendation of the OPR: which, of course, has no such democratic mandate. The role of the Minister in issuing a direction 99. The Minister’s fifth ground of appeal is that the judge erred in law in incorrectly characterising the role of the Minister issuing a s. 31 direction as being equivalent to a court in determining a challenge to a development plan, and consequently in stating the circumstances in which the Minister is permitted to issue a s. 31 direction. 100. As is evident from the grounds of appeal, this error is said to have been made at para. 276 of the judgment. What the judge said at para. 276 was:- “276. As the Minister, in making a s.31 direction is, like the court in the situations envisaged by Humphreys and Hogan JJ, concerned not with mere planning disagreements as between options each consistent with NPF and RSES objectives, but with discerning the legality or illegality of a development plan framed by the democratic decision of the local elected representatives, who have a constitutional status and who are entrusted with making such decisions by the legislature, it seems to me to follow that the Minister must, as must a court: • be very slow to interfere by way of s.31 direction - at least on grounds of irrationality of the planning authority’s decision; • respect the margin of appreciation in the planning authority, which I have identified above, as to the reconciliation of tensions between NPF and RSES development objectives; • where possible, generally interpret a development plan with a view to its validity rather than its invalidity.” 101. In my view, the Minister and the OPR have misunderstood the judgment. The judge did not equate the power conferred on the Minister by s. 31 with the power of a court on an application by way of judicial review. The passage relied on is directed to the exercise of the power rather than the nature of the power. Inasmuch as the Minister acknowledges that Tristor is still good law, he effectively acknowledges that the review or evaluation of a development plan for consistency is a review or evaluation for illegality. The premise of the approach – which Holland J. found was the appropriate approach – is that the elected members are entrusted by the legislature in the first instance with the making of the development plan and, in the constitutional and legal order, ought to be afforded a degree of deference and a margin of appreciation. The Minister – and the OPR before him – is entitled and obliged, based on an evaluative judgment, to form an opinion as to the consistency of the development plan with the relevant objectives. The point that the judge was making was that the OPR and the Minister, in forming their opinion as to illegality, ought to exercise a degree of restraint which recognises the role of the elected members in assessing, in the first instance, whether the development plan was consistent with the relevant objectives. 102. It seems to me that what Holland J. had to say about the need for restraint can be traced back to the reasons given first by the OPR and later by the Minister for the recommendation; which was not simply that they disagreed with the Council but that the Council’s insistence on keeping the 0/0 objective was irrational. On the facts of this case, it was the OPR and the Minister who set the bar at unreasonableness rather than a difference of opinion. In the end, as I have explained, the judge expressly found (at para. 318) that it was unnecessary to decide the rationality issue. Contrary to the Minister’s apprehension, I do not understand the judge to have already decided at para. 276 that the role of the Minister in issuing a s. 31 direction was the same as that of a court determining a challenge to a development plan. 103. As I have said, Holland J. commented on Mount Salus’s arguments as to irrationality and unreasonableness, without deciding the issue. In its respondent’s notice, Mount Salus sought to reintroduce this question as an additional ground on which the decision of the High Court should be affirmed. However, it seems to me that if the decision of the High Court is found to be correct on the grounds on which it was reached, it will not be necessary to address the additional grounds. The opinions of the OPR and the Minister 104. The Minister’s seventh ground of appeal – mirrored precisely in the OPR’s tenth – goes to the heart of the appeal. It is said that the High Court judge erred in holding that the objectives of the NPF and RSES are so internally inconsistent that consistency with all of those objectives will never be possible; that in consequence the planning authority can adopt individual objectives of a development plan that are not consistent with individual objectives of the NPF having regard to what they consider to be the appropriate trade-offs between the objectives of the NPF and the RSES; and with the Minister having no jurisdiction to intervene in such circumstances save where the Council acts irrationally. The judge is said to have so found at paras. 199 to 208. 105. Again, it seems to me, the Minister has misunderstood what the judge said. Not least, as I have explained, the judge did not say that the power of the Minister to intervene arose only in the event of irrationality. Nor did he say that the planning authority can adopt individual objectives of a development plan which are not consistent with individual objectives of the NPF. 106. The paragraphs of the High Court judgment identified in the notices of appeal are the judge’s consideration under the heading “Planning Policies & Objectives in tension – Trade- Offs & Reconciliation – Discretion.” In the referenced paragraphs the judge was addressing the applicant’s submission that the Minister had erred in law in failing to appreciate the degree of DLRCC’s discretion in balancing the many and competing planning objectives in making the development plan. It was never the applicant’s case that established inconsistency in certain respects could be justified or set off against consistency in other respects. Rather, the applicant’s argument was that consistency has to be judged taking into account the NPF and RSES objectives as a whole, and by reference to the development plan as a whole. 107. Holland J. started by observing that it is perfectly clear that a policy favouring residential development may, as to a particular location or area, be in tension, or even irreconcilable with, heritage protection. That, it seems to me, cannot be gainsaid. The judge conjured the spectre of an apartment block in the grounds of St. Patrick’s Cathedral or St. Stephen’s Green. Absent binding policy or law – said the judge – there are no trump cards. Rather, the choice of a trade-off, compromise or preference between competing policy objectives is a matter of planning judgment. 108. In this case, said the judge, it was obvious that, as to the 0/0 Objective Areas, the legitimate planning interest and policy of maximising compact residential development on transport corridors was, at least, in tension with the legitimate planning interest in and policy of preserving the architectural heritage of the Killiney and Dalkey areas. Citing the judgment of Lord Reed in Tesco Stores Ltd. v. Dundee City Council [2012] UKSC 13 and several Irish cases in which that was followed, the judge observed that development plans are full of broad statements of policy, many of which may be mutually irreconcilable, so that in a particular case one must give way to another. Such matters – said Lord Reed – fall within the jurisdiction of planning authorities and their exercise of judgment can only be challenged on the ground that it is irrational or perverse. 109. I pause here to emphasise that the cases under consideration were concerned with judicial review of development plans and not with the exercise