High Court allows costs order for unauthorized development case including investigation expenses and legal costs adjudication.

[2026] IEHC 407 THE HIGH COURT PLANNING & ENVIRONMENT CIRCUIT APPEAL DUBLIN CIRCUIT COUNTY OF THE CITY OF DUBLIN [High Court Record No.: H.CA.2025.0000329] [Circuit Court Record No.: 2025 5748 Co. Dublin] IN THE MATTER OF THE PLANNING AND DEVELOPMENT ACT 2000 NOTICE OF MOTION FOR RELIEF UNDER SECTION 160 OF THE PLANNING AND DEVELOPMENT ACT 2000 BETWEEN SOUTH DUBLIN COUNTY COUNCIL RESPONDENT/PLAINTIFF AND THRESHFORD LIMITED, MULLNASSA LIMITED AND BRANACH DEVELOPMENTS LIMITED APPELLANTS/DEFENDANTS AND THE HIGH COURT PLANNING & ENVIRONMENT CIRCUIT APPEAL DUBLIN CIRCUIT COUNTY OF THE CITY OF DUBLIN

[High Court Record No.: H.CA.2025.0000330] [Circuit Court Record No.: 2025 5894 Co. Dublin]

IN THE MATTER OF THE PLANNING AND DEVELOPMENT ACT 2000 NOTICE OF MOTION FOR RELIEF UNDER SECTION 160 OF THE PLANNING AND DEVELOPMENT ACT 2000 BETWEEN JOHN O’NEILL APPLICANT/RESPONDENT AND BRANACH DEVELOPMENTS LIMITED AND MULLNASSA LIMITED RESPONDENTS/APPELLANTS (No. 2)

Commencement of works: mid-August 2025 Date of Circuit Court order: 19 December 2025 Date of principal judgment: 3 June 2026 Date of hearing on form of order: 22 June 2026

JUDGMENT of Humphreys J. delivered on Friday 26 June 2026

1. In addressing the unauthorised development at issue here, I granted a prohibitory injunction but, at the request of the respondents, allowed further submissions on the form of the mandatory remediation injunction. Following those submissions some adjustments are being made, in particular an extension of the total remediation time from 6 weeks to 13 weeks. Judgment history

2. In South Dublin County Council v. Threshford Limited and Ors, O'Neill v. Branach Developments Limited and Anor (No. 1) [2026] IEHC 342 (Unreported, High Court, 3 June 2026), I dismissed the appeal and affirmed the Circuit Court’s orders, holding that the works constituted unauthorised development and were not exempt. I ordered the respondents to cease the development, remove the structures, and restore the lands to their prior condition, with costs awarded against them.

3. The purpose of the present judgment is to set out for the record the order made on 22 June 2026 by way of mandatory s. 160 relief. Procedural history

4. When the matter was listed on 3 June 2026 following the No. 1 judgment, I provided for all parties to make submissions on the form of the order and costs within one week with the matter to be listed again on 10 June 2026.

5. On 10 June 2026, Mr O’Neill had prepared a submission on costs, and the respondents had prepared a remediation proposal.

6. I ordered as follows:

(i) the parties were to reply to their respective submissions within a further week;

(ii) the matter to be mentioned on 17 June 2026 for further directions;

(iii) by consent there be a slip rule change to the original order to correct a typo; and

(iv) by consent the proposed order for the council’s costs in the Circuit Court be made per para. 200(xii) of the No. 1 judgment in the SDCC case – the order of the Circuit Court as to costs be affirmed on the basis that there be an order for costs in the Circuit Court (including reserved costs and the costs of written submissions and including a certificate for junior counsel and senior counsel as granted by that court)

being awarded to the applicant against the respondents jointly and severally to be taxed in default of agreement.

7. I also afforded the respondents a further week to rectify the problem of their consultant posing as an architect despite not being registered, a position the respondents very unwisely doubled down on when challenged.

8. On 17 June 2026, the council had produced a further submission rejecting the proposals and lack of detail in the respondents’ draft plan. Mr O’Neill also sought remediation of foundations on the green field area outside Chianti Park.

9. Rather than have further rounds of tit-for-tat on the details of the plan, the matter was then adjourned to 22 June 2026 for the court to resolve the disagreement by way of directions as to the detail of the plan. The issue to be dealt with was to be the remediation order, with the question of a possible stay and costs to follow later.

10. On the issue of Mr Donoghue’s improper use of the statutorily-protected title of architect when he is merely an architectural graduate, he had filed an affidavit by the mention date confirming that he now understood and was going to comply with the legislation, so no further action by me was necessary. Remediation plan

11. The No. 1 judgment proposed a period of 6 weeks for the remediation. In response the respondents initially suggested removal of 1 unit per week over 29 weeks. This led to a Module II on the form of the mandatory orders.

12. To put this in context, when the respondents were confronted with the fact of having engaged in unauthorised development, their reply was that the new dwellings were the same structures as the old and merely alteration/improvement. The old were mobile home type dwellings that could be moved in hours. The new structures took four months to put up. When asked to remove them, the initial answer that it would take six months doesn’t sound like we are talking about the same structures. In fact the respondents’ approach to removal is incompatible with what would apply if the mobile homes were still in place, which unfortunately completely undermines their claim that these dwellings are the same structures, merely having been altered or improved.

13. Perhaps in view of this potential difficulty, the respondents assured all concerned of their willingness to remediate, and did not strongly contest the council’s counter-proposals although they did make an issue of the bond and they are going to make an issue of the stay.

14. At the hearing of Module II on 22 June 2026, there was no particularly prolonged dispute about the format of the order and remediation plan, and a timeline of a total of 13 weeks was formulated following discussion with the parties.

15. The bond was resisted but this is a standard term for a planning permission particularly for large schemes and so by analogy is something that can reasonably be considered in asking whether a developer should be permitted to carry out remediation as opposed to having that done directly by the council without the risk of further delay. While there is a modest degree of financial inconvenience for the respondents, they could have avoided serious financial implications by stopping work when they got the warning letter from the council, when they got warning letters from Mr O’Neill, when they got the enforcement order, when proceedings were issued, when an injunction was sought. But no – they just stood on the accelerator through all of those flashing red lights, in the hope of creating a fait accompli before they were brought to a halt. So financial hardship to them as a result is on them, not on the applicants. A bond will provide some assurance that the remediation will actually be carried out and will put to the test the respondents’ stated willingness to carry out the remediation. While there was no evidence about the cost of the remediation works, you don’t need to know much about building costs to know that EUR 150,000 would only cover a fraction of the works that are going to be required. So a court can draw on such a matter of common knowledge, especially where there was no argument that this would exceed the costs of the works (only that it would exceed what was convenient for the respondents). Outstanding issues

16. The outstanding issues are set out in Annex IV. The stay will be the next item to be addressed on 6 July 2026, and other costs issues will be addressed if time permits.

17. For information, there are set out in the annexes the following:

(i) Annex I – orders under s. 160 – 3 June 2026 (in both cases, as amended under the slip rule);

(ii) Annex II – order regarding an element of costs – 10 June 2026 (SDCC case);

(iii) Annex III – orders made on foot of the present judgment (in both cases, as amended under the slip rule); and

(iv) Annex IV – matters remaining to be decided. Order

18. For the foregoing reasons, the order made on 22 June 2026 was in the terms set out in Annex III.

ANNEXES

ANNEX I – Orders of 3 June 2026 (prohibitory s. 160 orders - as amended under the slip rule)

PLANNING AND ENVIRONMENT 2025 329 CA Wednesday the 3rd day of June 2026 BEFORE MR JUSTICE HUMPHREYS IN THE MATTER OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) NOTICE OF MOTION FOR RELIEF UNDER SECTION 160 OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) BETWEEN/ SOUTH DUBLIN COUNTY COUNCIL RESPONDENT / PLAINTIFF -AND- THRESHFORD LIMITED, MULLNASSA LIMITED AND BRANACH DEVELOPMENTS LIMITED APPELLANTS / DEFENDANTS The within proceedings coming before the Court for hearing on the 13th day of May 2026 pursuant to the Notice of Appeal of the Appellants/Defendants filed on the 19th day of December 2025 in the presence of Counsel for the Respondent/Plaintiff and Counsel for the Appellants/Defendants Whereupon and on reading said Notice of Appeal and the Affidavits (2) of Ann Mulcrone filed on the 23rd day of March 2026 and the 12th day of May 2026 and the Affidavit of Cian Harte filed on the 15th day of April 2026 and the documents and exhibits in said Affidavits referred to and the written legal submissions filed herein and on hearing what was offered by said respective Counsel The COURT WAS PLEASED to reserve its judgment herein And the written judgment having been delivered electronically on this day and the detailed reasons for the Decision having been set out in the Judgment of the Court delivered electronically to the parties on this day And the matter coming on for mention on this day and on hearing the parties on foot of the said judgment IT IS ORDERED that

1. The appeal be and hereby is dismissed

2. The Order of the Circuit Court of the 19th day of December 2025 the subject of the within proceedings be affirmed on the basis of being varied by way of prohibitory order as set out below and on the basis of being varied by way of mandatory and further order(s) in a manner to be determined by order(s) of the court following submissions on the form of provisional orders

3. There be a prohibitory order to be effective immediately under s. 160 of the 2000 Planning and Development Act restraining the Appellants/Defendants and their directors or officers or any person having notice of the order from at any time: a. carrying out any works on any of the lands on which the unauthorised development took place save in accordance with an order of the Court; b. permitting any use of any of such lands (including occupation of any structures) save in accordance with an order of the Court; c. re-erecting on such lands any of the caravans and/or mobile homes and/or other structures that have been removed save in accordance with an order of the Court And IT IS ORDERED that

4. The parties do have liberty to make written legal submissions (without attempting revisit any findings in the judgment) on the form of the provisional further orders and as to costs said submissions to be made by 9:30am on Wednesday the 10th day of June 2026 and the parties to reply to submissions made by other parties by 9:30am on Wednesday the 17th day of June 2026;

5. The Appellants/Defendants be required to submit a detailed draft remediation and landscaping plan by 9:30am on Wednesday the 10th day of June 2026 said plan to specify both a. the steps the Appellants/Defendants intend to take to comply with the order if the provisional order is made as drafted and b. any proposed variations within the scope of the judgment with specific timelines in respect of all steps and the Respondent/Plaintiff to reply by 9:30am on Wednesday the 17th day of June 2026 specifying the extent to which (if at all) the proposals in the draft remediation and landscaping plan are agreed And the COURT DOTH DIRECT that any unsuccessful application to vary the provisional order set out in the judgment may be the subject of an adverse costs order (inter alia pursuant to O. 103 r. 40(4) RSC) and that any improper attempt to revisit the findings of the judgment in the context of submissions on the form of the order or costs may be the subject of an adverse costs order

IT IS FURTHER ORDERED that there be liberty to apply including in the event of non-compliance with any order of the Court And the within proceedings do stand adjourned to 9:30am on Wednesday the 10th day of June 2026 for mention [ADVHU] … REGISTRAR Perfected 03/06/2026 South Dublin County Council Solicitor for the Respondent / Plaintiff Harrington & Co Solicitor Solicitor for the Appellants / Defendants

Amended pursuant to the Order of Mr Justice Humphreys dated the 10th day of June 2026 and pursuant to Order 28 Rule 11 of the Rules of the Superior Courts (as amended) with the insertion of the text as set out in bold and underlined … REGISTRAR 10th day of June 2026

PLANNING AND ENVIRONMENT 2025 330 CA Wednesday the 3rd day of June 2026 BEFORE MR JUSTICE HUMPHREYS IN THE MATTER OF AN APPLICATION PURSUANT TOTHE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) AND THE REGULATIONS MADE THEREAFTER NOTICE OF MOTION FOR RELIEF UNDER SECTION 160 OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) BETWEEN/ JOHN O’NEILL RESPONDENT / APPLICANT -AND- BRANACH DEVELOPMENTS LIMITED AND MULLNASSA APPELLANTS / RESPONDENTS The within proceedings coming before the Court for hearing on the 13th day of May 2026 pursuant to the Notice of Appeal of the Appellants/Respondents filed on the 19th day of December 2025 in the presence of Counsel for the Respondent/Applicant and Counsel for the Appellants/Respondents Whereupon and on reading said Notice of Appeal and the Affidavit of Keith McDermott filed on the 26th day of March 2026 and the pleadings and affidavits filed in respect of the within proceedings and on hearing what was offered by said respective Counsel The COURT WAS PLEASED to reserve its judgment herein And the written judgment having been delivered electronically on this day and the detailed reasons for the Decision having been set out in the Judgment of the Court delivered electronically to the parties on this day And the matter coming on for mention on this day and on hearing the parties on foot of the said judgment IT IS ORDERED that

1. The appeal be and hereby is dismissed

2. The Order of the Circuit Court of the 19th day of December 2025 the subject of the within proceedings be affirmed on the basis of being varied by way of prohibitory order as set out below and on the basis of being varied by way of mandatory and further order(s) in a manner to be determined by order(s) of the court following submissions on the form of provisional orders

3. There be a prohibitory order to be effective immediately under s. 160 of the 2000 Planning and Development Act restraining the Appellants/Respondents and their directors or officers or any person having notice of the order from at any time: a. carrying out any works on any of the lands on which the unauthorised development took place save in accordance with an order of the Court; b. permitting any use of any of such lands (including occupation of any structures) save in accordance with an order of the Court; c. re-erecting on such lands any of the caravans and/or mobile homes and/or other structures that have been removed save in accordance with an order of the Court And IT IS ORDERED that

4. The parties do have liberty to make written legal submissions (without attempting revisit any findings in the judgment) on the form of the provisional further orders and as to costs said submissions to be made by 9:30am on Wednesday the 10th day of June 2026 and the parties to reply to submissions made by other parties by 9:30am on Wednesday the 17th day of June 2026;

5. The Appellants/Respondents be required to submit a detailed draft remediation and landscaping plan by 9:30am on Wednesday the 10th day of June 2026 said plan to specify both a. the steps the Appellants/Respondents intend to take to comply with the order if the provisional order is made as drafted and b. any proposed variations within the scope of the judgment with specific timelines in respect of all steps and the Respondent/Plaintiff to reply by 9:30am on Wednesday the 17th day of June 2026 specifying the extent to which (if at all) the proposals in the draft remediation and landscaping plan are agreed; And the COURT DOTH DIRECT that any unsuccessful application to vary the provisional order set out in the judgment may be the subject of an adverse costs order (inter alia pursuant to O. 103 r. 40(4) RSC) and that any improper attempt to revisit the findings of the judgment in the context of submissions on the form of the order for costs may be the subject of an adverse costs order IT IS FURTHER ORDERED that there be liberty to apply including in the event of non-compliance with any order of the Court And the within proceedings do stand adjourned to 9:30am Wednesday the 10th day of June 2026 for mention [ADVHU] … REGISTRAR Perfected 03/06/2026 BKC Solicitors Solicitor for the Applicant / Respondent Harrington & Co Solicitor Solicitor for the Respondents / Appellants

ANNEX II – Order of 10 June 2026

PLANNING AND ENVIRONMENT 2025 329 CA Wednesday the 10th day of June 2026 BEFORE MR JUSTICE HUMPHREYS IN THE MATTER OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) NOTICE OF MOTION FOR RELIEF UNDER SECTION 160 OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) BETWEEN/ SOUTH DUBLIN COUNTY COUNCIL RESPONDENT / PLAINTIFF -AND- THRESHFORD LIMITED, MULLNASSA LIMITED AND BRANACH DEVELOPMENTS LIMITED APPELLANTS / DEFENDANTS The within proceedings coming before the Court for mention on this day in the presence of Counsel for the Respondent/Plaintiff and Counsel for the Appellants/Defendants Whereupon and on reading the Notice of Appeal of the Appellants/Defendants filed on the 19th day of December 2025 and the Affidavits (2) of Ann Mulcrone filed on the 23rd day of March 2026 and the 12th day of May 2026 and the Affidavit of Cian Harte filed on the 15th day of April 2026 and the documents and exhibits in said Affidavits and the Judgment of this Court dated the 3rd day of June 2026 and the Order of the High Court dated the 3rd day of June 2026 and the written legal submissions filed herein and on hearing what was offered by said respective Counsel In accordance with paragraph 200 (xii) of the aforementioned judgment IT IS ORDERED that the Order of the Circuit Court as to costs dated the 19th day of December 2025 the subject of the within Appeal be affirmed on the basis that there be an order for costs in the Circuit Court (including reserved costs and the costs of written submissions and including a certificate for junior counsel and senior counsel as granted by that Court) being awarded to the Respondent/Plaintiff against the Appellants/Defendants jointly and severally to be taxed in default of agreement And IT IS ORDERED that all parties do have liberty to reply to submissions in so far as they relate to the balance of the aforementioned Judgment by the 17th day of June 2026 And IT IS ORDERED that the balance of the Judgment of the 3rd day of June 2026 which remains outstanding (including outstanding costs) in respect of the within proceedings do stand adjourned to 9:30am on Wednesday the 17th day of June 2026 for mention [ADVHU] …

REGISTRAR Perfected 10/06/2026 South Dublin County Council Solicitor for the Respondent / Plaintiff Harrington & Co Solicitor Solicitor for the Appellants / Defendants

ANNEX III – Orders of 22 June 2026 (mandatory s. 160 orders – as amended under the slip rule)

PLANNING AND ENVIRONMENT 2025 330 CA Monday the 22nd day of June 2026 BEFORE MR JUSTICE HUMPHREYS IN THE MATTER OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) NOTICE OF MOTION FOR RELIEF UNDER SECTION 160 OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) BETWEEN/ JOHN O’NEILL RESPONDENT / PLAINTIFF AND BRANACH DEVELOPMENTS LIMITED AND MULLNASSA APPELLANTS / DEFENDANTS The within proceedings coming before the Court for mention on this day in the presence of Counsel for the Respondent/Plaintiff and Counsel for the Appellants/Defendants Whereupon and on reading said Notice of Appeal and the Affidavit of Keith McDermott filed on the 26th day of March 2026 and the pleadings and affidavits filed in respect of the within proceedings and on hearing what was offered by said respective Counsel THE COURT DOTH GRANT

1. In each case there a mandatory order under s. 160 of the 2000 Act requiring the respondents to take the following steps (such order to cease to have effect (without prejudice to the consequences of any breach that has already occurred) if vacant possession of the entire lands on which the unauthorised development occurred is surrendered to the council with the consent of the council in accordance with the order), in accordance with the remediation plan scheduled to the order, to be concluded within 13 weeks from 22 June 2026, to remove all structures erected since August 2025 including remnants of previous structures incorporated in the new structures, which includes removal of all foundations, and to restore the lands, in accordance with the said remediation plan, subject to any further orders or directions of the court, to a condition representing a landscaped finish to the status quo on each part of the lands as it stood:

(a) in the case of trees, hedges or other vegetation, immediately prior to their removal (i.e., by replanting trees, hedges and vegetation as appropriate);

(b) in the case of dwellings, following the removal of all caravans and mobile homes (or other dwellings however described) and prior to the erection of modular houses and foundations; and

(c) in the case of other works, immediately prior to such works; and subject in each case to such consequential and ancillary landscaping as may be required by the remediation and landscaping plan;

2. In each case there be a mandatory order under s. 160 of the 2000 Act requiring the respondents to surrender to the council vacant possession of the entire lands within their possession or ownership within which the unauthorised development occurred for the purposes of remediation by the council, either in the event that the respondents and the council agree such surrender or in the event that the respondents breach any provision of this order and the council thereafter requests such surrender, and that in the event of any dispute as to the extent of the lands required to be surrendered to the council, the matter be determined by the court, and that in the event of the council taking exclusive possession of the lands pursuant to this order, the council be required to carry out all necessary demolition and restoration works as set out above in this order, subject to any further directions of the court, within 13 weeks from taking such possession or such further period as may be allowed by the court, and that in that eventuality, the return of possession of the lands to the respondents will be determined by further order of the court subject to completion of remediation and landscaping and to s. 154(6) and (7) of the 2000 Act;

3. AND THE COURT DOTH DIRECT THAT provisionally in each case there be an order for costs (including reserved costs and the costs of written submissions) being awarded to the applicant against the respondents subject to contrary submissions within 7 days;

4. fFor the avoidance of doubt, the order for costs if made shall include an order for the costs of legal costs adjudication;

5. fFor the avoidance of doubt, any unsuccessful application to vary any provisional order as to costs proposed in this judgment may be addressed pursuant to O. 103 r. 40(4) RSC;

6. tThere be liberty to apply; and

7. tThe matter be listed on 09:30 on Monday 6 July for hearing of outstanding issues of:

(i) disagreement about the method statement if any,

(ii) the stay application,

(iii) costs of the proceedings to date,

(iv) payment on account of costs if ordered,

(v) costs of the foregoing,

(vi) any further mention date. … REGISTRAR Perfected 22nd June 2026 South Dublin County Council Solicitor for the Respondent / Plaintiff Harrington & Co Solicitor Solicitor for the Appellants / Defendants SCHEDULE HEREINBEFORE REFERRED TO REMEDIATION PLAN STEP 1 The Landscape and Remediation Plan shall not be considered a mere visual layout or planting design. It must be accompanied by a comprehensive, step-by-step Method Statement detailing the sequence of physical operations required to prepare the site. Financial Performance Bond: It is recommended to request that the Court orders a lodged financial bond held by SDCC. This money will only be released back to the developer after an SDCC Engineer/Parks Superintendent signs off on the successful establishment of the landscape plan at the end of Year 3. In the amount of EUR 150,000 For mention 6 July 2026 to address any disagreement on the method statement. Within 2 weeks STEP 2

1. Site Clearance and Waste Auditing Before any green restoration can begin, the developer must prove that all unauthorised materials have been legally removed from the Dublin Mountains site. Comprehensive Waste Audit: Require a full, independent waste-tracking log with official tipping dockets. This must prove all unauthorised structures, concrete footings, hardcore, tarmac, and hidden construction debris have been disposed of at licensed facilities. Within a further 5 weeks STEP 3

• Visual Validation: Mandate a post-clearance inspection by an SDCC engineer before any topsoil is placed, ensuring no buried waste remains to contaminate groundwater or disrupt future root growth. Within 1 further week STEP 4

2. Soil Remediation and Profile Reinstatement Because the site has suffered severe compaction from unauthorised structures and heavy plant machinery, standard rotovating is entirely insufficient. The developer must restore the natural subsoil-to-topsoil hydrological pathway. REMEDIATION SOIL PROFILE SPEC Topsoil Layer: ──► 150mm - 300mm Certified BS3882 Subsoil Layer: ──► Subsoil ripped to 450mm depth Base Layer: ──► Deep sub-grade de-compaction

• Deep Sub-grade De-compaction: Mandate deep-ripping or "sub-soiling" to a minimum depth of 450mm across all disturbed areas. This breaks up the hard pan layer created by construction traffic, preventing perched water tables and stagnant surface flooding.

• Topsoil Depth and Quality Specification: Require a minimum layer of 150mm to 300mm of good quality, clean uncontaminated topsoil across the entire site. Within 2 weeks STEP 5

3. Native Hedgerow Specifications

To repair the visual scar on the Dublin Mountains landscape and restore local ecological corridors, boundaries must match the surrounding agricultural fabric.

• Species Mix (80/20 Rule): The hedgerow must consist of a minimum 80% Hawthorn (Crataegus monogyna) and Blackthorn (Prunus spinosa) as the structural matrix. The remaining 20% must comprise a native rural mix including Holly (Ilex aquifolium), Hazel (Corylus avellana), Guelder Rose (Viburnum opulus) and Spindle (Euonymus europaeus)

• Planting Density and Arrangement: Spec a double-staggered row planted at a density of 5 to 6 plants per linear metre. Rows must be spaced 300mm apart with plants staggered at 300mm centres to create a dense, stock-proof, and secure barrier.

• Plant Stock Size: Specify bare-root transplants, 60cm–90cm in height, which establish much faster and with lower failure rates in exposed upland environments than overly mature hedgerow plants.

• Protection and Establishment: Use heavy-duty biodegradable mulch mats (to suppress weeds without plastic pollution) and timber post-and-wire fencing on the internal side to protect the young hedge from grazing animals or human interference during the first 3 years.

• Total Planting Bed Width: The developer must excavate and prepare a continuous 1.5-metre wide strip of topsoil. This width ensures the roots of the double-staggered planting rows have enough un-compacted soil to expand without immediate lateral competition from surrounding weeds.

• Setback from the Boundary Line: The core of the hedge must be centred exactly 500mm back from the physical boundary line. This prevents the root systems from undermining road structures and gives the mature hedge room to expand naturally without encroaching onto public roadways or neighbouring lands.

• Fencing Placement: The protective timber post-and-wire fence must be installed on the internal side, sitting at least 1.0 to 1.5 metres away from the young saplings. If the fence is installed any closer, livestock or heavy machinery will easily reach over the barrier and graze on or crush the tender new growth.

• Timber Posts: All posts must be pressure-treated, pressure-impregnated softwood conforming to Irish Standard IS 435. Strainer/corner posts must be a minimum of 2.1 metres long with a 150mm top diameter, driven deeply into the subsoil. Intermediate posts must be 1.8 metres long with a 100mm top diameter, spaced no more than 3 metres apart.

• Wire Profile: The fence must feature a row of high-tensile galvanized sheep wire at the base to stop smaller animals. It must be topped by two rows of high-tensile barbed wire or a doublestrand plain galvanized top wire to prevent larger cattle or horses from leaning over and destroying the line.

4. Semi-Mature Tree Specifications To instantly break up the sightlines of the cleared site and incorporate it back into the adjoining field networks, hedgerow trees must have immediate physical presence.

• Native Upland Species: Trees must be native species suited to the Dublin Mountains foothills. Specify Sessile Oak (Quercus petraea), Rowan/Mountain Ash (Sorbus aucuparia), and Silver Birch (Betula pendula).

• Nursery Stock Size: Mandate Semi-Mature stock, specifically a minimum 16cm–18cm girth (Selected Standard to Heavy Standard). This ensures the trees are structurally resilient against high mountain winds and provide immediate visual remediation.

• Spacing: Trees should be integrated directly into the boundary hedgerow lines at irregular, natural intervals of 5 to 7 metres apart, avoiding artificial, perfectly straight lines.

• Underground Anchoring: Because of the exposed mountain location, use underground rootball guying systems rather than above-ground timber stakes. Above-ground stakes can snap or choke trees in high-velocity rural winds.

5. Nature-Based Drainage Ditches (SuDS Swales) Standard concrete pipes or deep, agricultural trenches are unacceptable. The developer must manage the site's altered hydrology using soft engineering.

• Vegetated Swales: Any required drainage ditches along the road frontage or field boundaries must be designed as shallow, wide vegetated swales with a maximum side-slope gradient of 1:3. This prevents soil erosion and allows the ditch to be safely maintained and mowed.

• Check Dams for Velocity Control: Because the site sits on a gradient in a mountainous area, the drainage plan must include natural stone or timber check dams spaced every 10 to 15 metres along the ditch. These dams slow down surface water velocity, encourage local ground infiltration, and prevent downstream siltation.

• Seeding and Silt Traps: The base of the ditches must be seeded with a specialized wet grass/marshland native seed mix (from certified Irish supplier) to actively filter runoff water.

6. Maintenance, Failure Guarantees, and Bonding A landscape plan must include:

• 3-Year Defects Liability Period: The developer must be legally responsible for a mandatory 3-year maintenance and watering contract.

• Failure Replacement Mandate: The plan must explicitly state that any tree, hedge plant, or seeded area that dies, fails, or becomes diseased within the first 3 years must be replaced by the developer at their own expense during the very next planting season (November to March). A further 4 weeks Amended pursuant to the Order of Mr Justice Humphreys dated the 22nd day of June 2026 and pursuant to Order 28 Rule 11 of the Rules of the Superior Courts (as amended) with the insertion of the text as set out in bold and underlined and the deletion of the text as struck through … REGISTRAR 22nd day of June 2026

PLANNING AND ENVIRONMENT 2025 329 CA Monday the 22nd day of June 2026 BEFORE MR JUSTICE HUMPHREYS IN THE MATTER OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) NOTICE OF MOTION FOR RELIEF UNDER SECTION 160 OF THE PLANNING AND DEVELOPMENT ACT 2000 (AS AMENDED) BETWEEN/ SOUTH DUBLIN COUNTY COUNCIL RESPONDENT / PLAINTIFF AND THRESHFORD LIMITED, MULLNASSA LIMITED AND BRANACH DEVELOPMENTS LIMITED APPELLANTS / DEFENDANTS The within proceedings coming before the Court for mention on this day in the presence of Counsel for the Respondent/Plaintiff and Counsel for the Appellants/Defendants Whereupon and on reading the Notice of Appeal of the Appellants/Defendants filed on the 19th day of December 2025 and the Affidavits (2) of Ann Mulcrone filed on the 23rd day of March 2026 and the 12th day of May 2026 and the Affidavit of Cian Harte filed on the 15th day of April 2026 and the Affidavit of Adrian Donoghue filed on the 18th day of June 2026 and the documents and exhibits in said Affidavits And on hearing said Counsel THE COURT DOTH GRANT

1. In each case there a mandatory order under s. 160 of the 2000 Act requiring the respondents to take the following steps (such order to cease to have effect (without prejudice to the consequences of any breach that has already occurred) if vacant possession of the entire lands on which the unauthorised development occurred is surrendered to the council with the consent of the council in accordance with the order), in accordance with the remediation plan scheduled to the order, to be concluded within 13 weeks from 22 June 2026, to remove all structures erected since August 2025 including remnants of previous structures incorporated in the new structures, which includes removal of all foundations, and to restore the lands, in accordance with the said remediation plan, subject to any further orders or directions of the court, to a condition representing a landscaped finish to the status quo on each part of the lands as it stood:

(a) in the case of trees, hedges or other vegetation, immediately prior to their removal (i.e., by replanting trees, hedges and vegetation as appropriate);

(b) in the case of dwellings, following the removal of all caravans and mobile homes (or other dwellings however described) and prior to the erection of modular houses and foundations; and

(c) in the case of other works, immediately prior to such works; and subject in each case to such consequential and ancillary landscaping as may be required by the remediation and landscaping plan;

2. In each case there be a mandatory order under s. 160 of the 2000 Act requiring the respondents to surrender to the council vacant possession of the entire lands within their possession or ownership within which the unauthorised development occurred for the purposes of remediation by the council, either in the event that the respondents and the council agree such surrender or in the event that the respondents breach any provision of this order and the council thereafter requests such surrender, and that in the event of any dispute as to the extent of the lands required to be surrendered to the council, the matter be determined by the court, and that in the event of the council taking exclusive possession of the lands pursuant to this order, the council be required to carry out all necessary demolition and restoration works as set out above in this order, subject to any further directions of the court, within 13 weeks from taking such possession or such further period as may be allowed by the court, and that in that eventuality, the return of possession of the

lands to the respondents will be determined by further order of the court subject to completion of remediation and landscaping and to s. 154(6) and (7) of the 2000 Act;

3. AND THE COURT DOTH DIRECT THAT provisionally in each case there be an order for costs (including reserved costs and the costs of written submissions) being awarded to the applicant against the respondents subject to contrary submissions within 7 days;

4. fFor the avoidance of doubt, the order for costs if made shall include an order for the costs of legal costs adjudication;

5. fFor the avoidance of doubt, any unsuccessful application to vary any provisional order as to costs proposed in this judgment may be addressed pursuant to O. 103 r. 40(4) RSC;

6. tThere be liberty to apply; and

7. tThe matter be listed on 09:30 on Monday 6 July for hearing of outstanding issues of:

(i) disagreement about the method statement if any,

(ii) the stay application,

(iii) costs of the proceedings to date,

(iv) payment on account of costs if ordered,

(v) costs of the foregoing,

(vi) any further mention date. … REGISTRAR Perfected 22nd June 2026 South Dublin County Council Solicitor for the Respondent / Plaintiff Harrington & Co Solicitor Solicitor for the Appellants / Defendants SCHEDULE HEREINBEFORE REFERRED TO REMEDIATION PLAN STEP 1 The Landscape and Remediation Plan shall not be considered a mere visual layout or planting design. It must be accompanied by a comprehensive, step-by-step Method Statement detailing the sequence of physical operations required to prepare the site. Financial Performance Bond: It is recommended to request that the Court orders a lodged financial bond held by SDCC. This money will only be released back to the developer after an SDCC Engineer/Parks Superintendent signs off on the successful establishment of the landscape plan at the end of Year 3. In the amount of EUR 150,000 For mention 6 July 2026 to address any disagreement on the method statement. Within 2 weeks STEP 2

1. Site Clearance and Waste Auditing Before any green restoration can begin, the developer must prove that all unauthorised materials have been legally removed from the Dublin Mountains site. Comprehensive Waste Audit: Require a full, independent waste-tracking log with official tipping dockets. This must prove all unauthorised structures, concrete footings, hardcore, tarmac, and hidden construction debris have been disposed of at licensed facilities. Within a further 5 weeks STEP 3

• Visual Validation: Mandate a post-clearance inspection by an SDCC engineer before any topsoil is placed, ensuring no buried waste remains to contaminate groundwater or disrupt future root growth. Within 1 further week STEP 4

2. Soil Remediation and Profile Reinstatement Because the site has suffered severe compaction from unauthorised structures and heavy plant machinery, standard rotovating is entirely insufficient. The developer must restore the natural subsoil-to-topsoil hydrological pathway. REMEDIATION SOIL PROFILE SPEC Topsoil Layer: ──► 150mm - 300mm Certified BS3882 Subsoil Layer: ──► Subsoil ripped to 450mm depth Base Layer: ──► Deep sub-grade de-compaction

• Deep Sub-grade De-compaction: Mandate deep-ripping or "sub-soiling" to a minimum depth of 450mm across all disturbed areas. This breaks up the hard pan layer created by construction traffic, preventing perched water tables and stagnant surface flooding.

• Topsoil Depth and Quality Specification: Require a minimum layer of 150mm to 300mm of good quality, clean uncontaminated topsoil across the entire site. Within 2 weeks STEP 5

3. Native Hedgerow Specifications To repair the visual scar on the Dublin Mountains landscape and restore local ecological corridors, boundaries must match the surrounding agricultural fabric.

• Species Mix (80/20 Rule): The hedgerow must consist of a minimum 80% Hawthorn (Crataegus monogyna) and Blackthorn (Prunus spinosa) as the structural matrix. The remaining 20% must comprise a native rural mix including Holly (Ilex aquifolium), Hazel (Corylus avellana), Guelder Rose (Viburnum opulus) and Spindle (Euonymus europaeus)

• Planting Density and Arrangement: Spec a double-staggered row planted at a density of 5 to 6 plants per linear metre. Rows must be spaced 300mm apart with plants staggered at 300mm centres to create a dense, stock-proof, and secure barrier.

• Plant Stock Size: Specify bare-root transplants, 60cm–90cm in height, which establish much faster and with lower failure rates in exposed upland environments than overly mature hedgerow plants.

• Protection and Establishment: Use heavy-duty biodegradable mulch mats (to suppress weeds without plastic pollution) and timber post-and-wire fencing on the internal side to protect the young hedge from grazing animals or human interference during the first 3 years.

• Total Planting Bed Width: The developer must excavate and prepare a continuous 1.5-metre wide strip of topsoil. This width ensures the roots of the double-staggered planting rows have enough un-compacted soil to expand without immediate lateral competition from surrounding weeds.

• Setback from the Boundary Line: The core of the hedge must be centred exactly 500mm back from the physical boundary line. This prevents the root systems from undermining road structures and gives the mature hedge room to expand naturally without encroaching onto public roadways or neighbouring lands.

• Fencing Placement: The protective timber post-and-wire fence must be installed on the internal side, sitting at least 1.0 to 1.5 metres away from the young saplings. If the fence is installed any closer, livestock or heavy machinery will easily reach over the barrier and graze on or crush the tender new growth.

• Timber Posts: All posts must be pressure-treated, pressure-impregnated softwood conforming to Irish Standard IS 435. Strainer/corner posts must be a minimum of 2.1 metres long with a 150mm top diameter, driven deeply into the subsoil. Intermediate posts must be 1.8 metres long with a 100mm top diameter, spaced no more than 3 metres apart.

• Wire Profile: The fence must feature a row of high-tensile galvanized sheep wire at the base to stop smaller animals. It must be topped by two rows of high-tensile barbed wire or a doublestrand plain galvanized top wire to prevent larger cattle or horses from leaning over and destroying the line.

4. Semi-Mature Tree Specifications To instantly break up the sightlines of the cleared site and incorporate it back into the adjoining field networks, hedgerow trees must have immediate physical presence.

• Native Upland Species: Trees must be native species suited to the Dublin Mountains foothills. Specify Sessile Oak (Quercus petraea), Rowan/Mountain Ash (Sorbus aucuparia), and Silver Birch (Betula pendula).

• Nursery Stock Size: Mandate Semi-Mature stock, specifically a minimum 16cm–18cm girth (Selected Standard to Heavy Standard). This ensures the trees are structurally resilient against high mountain winds and provide immediate visual remediation.

• Spacing: Trees should be integrated directly into the boundary hedgerow lines at irregular, natural intervals of 5 to 7 metres apart, avoiding artificial, perfectly straight lines.

• Underground Anchoring: Because of the exposed mountain location, use underground rootball guying systems rather than above-ground timber stakes. Above-ground stakes can snap or choke trees in high-velocity rural winds.

5. Nature-Based Drainage Ditches (SuDS Swales) Standard concrete pipes or deep, agricultural trenches are unacceptable. The developer must manage the site's altered hydrology using soft engineering.

• Vegetated Swales: Any required drainage ditches along the road frontage or field boundaries must be designed as shallow, wide vegetated swales with a maximum side-slope gradient of 1:3. This prevents soil erosion and allows the ditch to be safely maintained and mowed.

• Check Dams for Velocity Control: Because the site sits on a gradient in a mountainous area, the drainage plan must include natural stone or timber check dams spaced every 10 to 15 metres

along the ditch. These dams slow down surface water velocity, encourage local ground infiltration, and prevent downstream siltation.

• Seeding and Silt Traps: The base of the ditches must be seeded with a specialized wet grass/marshland native seed mix (from certified Irish supplier) to actively filter runoff water.

6. Maintenance, Failure Guarantees, and Bonding A landscape plan must include:

• 3-Year Defects Liability Period: The developer must be legally responsible for a mandatory 3-year maintenance and watering contract.

• Failure Replacement Mandate: The plan must explicitly state that any tree, hedge plant, or seeded area that dies, fails, or becomes diseased within the first 3 years must be replaced by the developer at their own expense during the very next planting season (November to March). A further 4 weeks Amended pursuant to the Order of Mr Justice Humphreys dated the 22nd day of June 2026 and pursuant to Order 28 Rule 11 of the Rules of the Superior Courts (as amended) with the insertion of the text as set out in bold and underlined and the deletion of the text as struck through … REGISTRAR 22nd day of June 2026

ANNEX IV – Matters outstanding

1. In the event of disagreement about the method statement – resolution of same

2. Stay

The respondents’ application for a stay on the basis of:

(a) a proposed leave to appeal application to the Supreme Court; and/or

(b) a proposed retention application.

3. Costs

a. Whether the council’s costs in the High Court should be on the High Court scale (per the council) or the Circuit Court scale (per the respondents).

b. Whether Mr O’Neill should be awarded costs of proceedings in the Circuit Court and/or the High Court.

c. Costs provisionally awarded in the order of 22 June 2026.

The provisional orders in the No. 1 judgment were:

(xi) in the O’Neill case, the order of the Circuit Court as to costs be affirmed on the basis that there be an order for costs in the Circuit Court (including reserved costs and the costs of written submissions and including a certificate for junior counsel as granted by that court) being awarded to the applicant against the respondents jointly and severally to be taxed in default of agreement;

(xiii) in each case, there be an order for costs in the High Court (including reserved costs and the costs of written submissions) being awarded to the applicants against the respondents jointly and severally and any issue as to the extent of such costs be determined, in default of agreement, by way of legal costs adjudication;

(xiv) in each case, the order for costs in the High Court shall include an order for the costs of legal costs adjudication; and

(xv) in the SDCC case, pursuant to s. 161(2) of the 2000 Act, the order for costs in the High Court shall include all costs or expenses reasonably incurred by the applicant in relation to the investigation and detection of the unauthorised development as well as in the proceedings, including costs incurred in respect of the remuneration and other expenses of employees, consultants and advisers in respect of those matters.

The provisional orders on 22 June 2026 as recorded in this No. 2 judgment are:

In each case:

There be an order for costs (including reserved costs and the costs of written submissions) being awarded to the applicant against the respondents subject to contrary submissions within 7 days;

For the avoidance of doubt, the order for costs if made shall include an order for the costs of legal costs adjudication;

4. Payment on account of costs

The further orders sought by Mr O’Neill were:

1. An order pursuant to Order 99 rule 2(5) of the Rules of the Superior Court, that the Respondents, jointly and severally, pay a reasonable sum on account and/or forthwith of the Applicant's costs pending taxation/adjudication.

2. An order pursuant to Order 99, rule 7(3) of the Rules of the Superior Court, that the parties exchange estimates of the Applicant's costs incurred to date within such short period as the court considers appropriate.

3. A direction that the parties endeavour to agree the amount to be paid on account within a 1 week thereafter.

4. In default of agreement on costs or the amount to be paid on account, an order that the court fix the amount to be paid on account on the written materials, or on a short further mention.

5. A direction that the sum so agreed or fixed be paid within 14 days of agreement, determination, or perfection of the relevant order, as the court considers appropriate.

6. A direction that the payment stand as a credit against the amount of costs ultimately taxed or adjudicated.

7. A direction that the Applicant's solicitor give the undertaking contemplated by Practice Direction HCl 25, namely that if taxation/adjudication yields a lower figure than the amount paid on account, any overpayment will be repaid forthwith.

6. If the court is minded to fix the amount now, the Applicant seeks an order in the sum of €60,000 to be paid within 14 days of perfection of the order.

7. If the court is not minded to fix the amount immediately, the Applicant respectfully seeks the exchange-and-agreement mechanism set out above, with liberty to apply or a short return date if no agreement is reached.

5. Costs of the foregoing

6. The setting of any further mention date