7, Thornhill Road, Mount Merrion, Blackrock, County Dublin, A94D1WS
Demolition of a garage to build a two-storey side extension, single-storey rear extension, and attic conversion.
D21A/0635 · Dun Laoghaire Rathdown County Council · Lodged 7 July 2021
- Reference
- D21A/0635
- Authority
- Dun Laoghaire Rathdown County Council
- Register status
- Decided
- Type
- Permission
- Received
- 7 July 2021
Summary
AI-generatedThe project involves demolishing an existing garage and outhouses to construct a two-storey side extension and a single-storey rear extension. It also includes an attic conversion with a rear dormer window and widening the driveway entrance.
Generated from the description above by an AI model and may contain mistakes. The council’s description is the authoritative record.
Official record
Development description
The development will consist of the demolition of the existing garage, various outhouses and the removal of all existing windows and external doors. We intend to erect a two storey extension to the side and a single storey extension to the back of the property . We also intend to convert the attic, construct a new flat roof dormer along the rear roof and widen the existing vehicular entrance
Land-use zoning
What this land is zoned for
“A To provide residential development and improve residential amenity while protecting the existing residential amenities”
Objective set by the COUNTY DEVELOPMENT PLAN 2022-2028 (2022–2028). The planning authority decides each application on its own merits — this is the zoning context, not a compliance assessment.
Read the zoning objectives in the development planBuilt & sold
What happened next
Beyond the decision: whether this development was built, and what property here has sold for.
Built — construction complete
A commencement notice records works starting on 14 March 2022.
Notified floor area: 218 m²
Recent sales nearby
within 500 m| Address | Date | Price | Distance |
|---|---|---|---|
| 33 Clonmore Rd, Mount Merrion, Dublin | Apr 2026 | €1,425,000 | 57 m |
| 28 South Ave, Mount Merrion, Dublin | Sept 2025 | €1,400,000 | 68 m |
| 24 South Ave, Mount Merrion, Dublin | Dec 2025 | €1,580,000 | 69 m |
| 32 South Ave, Mount Merrion, Dublin | Jan 2026 | €1,725,000 | 75 m |
| 14 South Avenue, Mount Merrion, Co Dublin | Sept 2025 | €920,000 | 127 m |
| Thornhill, Cherry Garth, Mount Merrion | Aug 2025 | €1,750,000 | 165 m |
| 49 Thornhill Oaks, Cherry Garth, Mount Merrionprice excludes VAT | Jan 2025 | €1,145,374 | 171 m |
| 62 Thornhill Oaks, Blackrock, Co. Dublinprice excludes VAT | Mar 2026 | €859,031 | 176 m |
Nearby properties, not this site — a guide to local values.
Sources: Building Control Management System (commencement notices) and the Residential Property Price Register, licensed under CC BY 4.0. Records are matched to this application by location and may not be exhaustive; always confirm against the official source before relying on them.
Key dates
Timeline
- Application received7 July 2021
- Decision issued27 August 2021
In the area
Applications near this site
Other planning applications within about 500 m — what else is being proposed or built nearby.
- GrantedAt this site
Permission is being sought for the demolition of the existing ground floor garage and single storey extension…
5, Thornhill Road, Mount Merrion, Co. Dublin
D09A/0672Dún Laoghaire–RathdownLodged 19 Nov 2009Extension
- GrantedAt this site
Permission for a domestic extension and alterations to existing semi-detached dwelling. The extension and…
3, Thornhill Road, Mount Merrion, Co. Dublin
D18B/0168Dún Laoghaire–RathdownLodged 11 Apr 2018Extension
- Granted30 m away
Single storey extension to side and rear of existing residence with new porch and associated works.…
13 Thornhill Road, Mount Merrion, Co. Dublin.
D02B/0091Dún Laoghaire–RathdownLodged 1 Mar 2002Extension
- Refused40 m away
For the demolition of 2 no. garages (one each at Nos. 33 and 35 Clonmore Road), and a glass house and…
Rear lands No. 33 & No. 35 Clonmore Road, Mount Merrion, Co. Dublin
D26A/0295Dún Laoghaire–RathdownLodged 16 Apr 2026Housing estate
- Granted40 m away
Demolition of existing single storey extension to front, side and rear. Construction of new single storey…
15 Thornhill Road, Mount Merrion, Co. Dublin.
D02B/0895Dún Laoghaire–RathdownLodged 4 Dec 2002Extension
- Granted40 m away
Raising pitched roof of existing extension to front. Alterations to front elevation including tyrolene…
15 Thornhill Road, Mount Merrion, Co. Dublin.
D02B/0436Dún Laoghaire–RathdownLodged 11 Jun 2002Extension
- Granted50 m away
Permission for development at this site. The development will consist of widening the entrance gate to front…
18, Thornhill Road, Mount Merrion, Co. Dublin
D13A/0274Dún Laoghaire–RathdownLodged 29 May 2013Alterations
- Granted50 m away
Permission for development at this site. The development will consist of — Demolition of existing garage
17, Thornhill Road, Mount Merrion, Dublin, A94EOW6
D20B/0358Dún Laoghaire–RathdownLodged 25 Feb 2021Extension
Related developments
Similar applications
Ranked by what these developments actually propose, not by matching words — so you can see how comparable applications were decided.
- GrantedExtension
The development will consist of the demolition of the existing garage, various outhouses and the removal of…
34, Thornhill Road, Mount Merrion, Blackrock, County Dublin, A94PE89
D18B/0390Dún Laoghaire–RathdownLodged 31 Aug 2018
- InvalidExtension
The development will consist of the conversion of the existing garage and the partial demolition of walls to…
38, Mount Prospect Park, Clontarf, Dublin 3
WEB1727/21Dublin CityLodged 6 Jul 2021
- GrantedExtension
The development will consist of the demolition of the utility room to rear of property, part of existing rear…
15, Cremore Crescent, Glasnevin, Dublin 11, D11 H2R2
5035/22Dublin CityLodged 13 Oct 2022
- InvalidExtension
The development will consist of the demolition of a rear single storey structure and garage to the side of…
48, Beech Hill Drive, Donnybrook, Dublin 4 D04 T2W1
WEB1047/23Dublin CityLodged 27 Jan 2023
- GrantedExtension
The development will involve the demolition of part of the existing gable wall and roof gable. We intend to…
88, Priory Avenue, Stillorgan, County Dublin, A94ND82
D22B/0041Dún Laoghaire–RathdownLodged 2 Feb 2022
- GrantedExtension
The development will consist of the demolition of an existing rear single storey extension and garage and the…
31 Mount Prospect Avenue, Clontarf, Dublin 3, D03 EV20
WEB2420/25Dublin CityLodged 18 Jun 2025
Community
Discussion
What local people think about this application.
Community sentiment
No votes yetNobody has voted on this application yet.
Community sentiment — a straw poll of people who visited this page, not a statutory submission. To make a valid observation you must submit it to the planning authority.
Sign in to have your say on this application.
No comments yet. Be the first to say what you think about this application.
Sign in to join the discussion on this application.
Comments are moderated and are the opinions of the people who wrote them. They form no part of the statutory planning process — to make a valid observation you must submit it to the planning authority.