12A, Northumberland Avenue, Dun Laoghaire, Co Dublin
Extension and conversion of a one-bedroom house into a three-bedroom house.
D21B/0252 · Dun Laoghaire Rathdown County Council · Lodged 21 May 2021
- Reference
- D21B/0252
- Authority
- Dun Laoghaire Rathdown County Council
- Register status
- Decided
- Type
- Permission
- Received
- 21 May 2021
Summary
AI-generatedThe project will convert an existing 63 sqm one-bedroom house into a 119 sqm three-bedroom house. This will be achieved through a two-storey rear extension, a single-storey front extension, and a front dormer attic conversion.
- Storeys
- 2
- Floor area
- 119 m²
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
Permission is sought for the conversion of the existing 63 sqm 1 bedroom house into a 119 sqm 3-bedroom house via the construction of a 2-storey rear extension, 1-storey front extension and dormer attic conversion to the front, along with associated site works
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.
Recent sales nearby
within 500 m| Address | Date | Price | Distance |
|---|---|---|---|
| 15 Northumberland Ave, Dun Laoghaire, Dublin | May 2025 | €1,250,000 | 47 m |
| 21a Mulgrave St, Dun Laoghaire, Dublin | Feb 2026 | €840,000 | 63 m |
| 8 Northumberland Ave, Dun Laoghaire, Dublin | Feb 2025 | €1,100,000 | 65 m |
| 30 Mulgrave St, Dun Laoghaire, Dublin | Nov 2025 | €1,800,000 | 81 m |
| 34 Northumberland Avenue, Dunlaoughaira, Co Dublin | Dec 2025 | €1,900,000 | 92 m |
| 63 Mulgrave Street, Dun Laoghaire, Co. Dublin | Oct 2025 | €765,000 | 94 m |
| 32 Mulgrave St, Dun Laoghaire, Dublin | Jul 2025 | €880,000 | 96 m |
| 85/86 Patrick Street, Dun Laoghaire, Co. Dublin | Mar 2025 | €417,500 | 107 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 received21 May 2021
- Decision issued7 July 2021
- Appeal submitted3 August 2021
- Appeal decided8 March 2022
In the area
Applications near this site
Other planning applications within about 500 m — what else is being proposed or built nearby.
- RefusedAt this site
Permission is sought for the conversion of the existing 63 SqM 1-bedroom house into a 100 SqM 2-bedroom house…
12A, Northumberland Avenue, Dun Laoghaire, Dublin, A96HY76
D23B/0296Dún Laoghaire–RathdownLodged 20 Jun 2023Extension
- InvalidAt this site
Conversion of the existing 63sqm 1-bedroom house into a 100sqm 2-bedroom house via the construction of a…
12A, Northumberland Avenue, Dun Laoghaire, Dublin, A96HY76
D23B/0164Dún Laoghaire–RathdownLodged 11 Apr 2023Extension
- GrantedAt this site
Permission for demolition of no 12B Northumberland Avenue, together with demolition and rebuilding in new…
12B Northumberland Avenue & Northumberland Hall, Northumberland Avenue, Dun Laoghaire, Co Dublin
D13A/0072Dún Laoghaire–RathdownLodged 15 Feb 2013Demolition
- GrantedAt this site
Retention of development to include — steel structures, balustrades and cladding to rear balcony
12 Northumberland Avenue, Dun Laoghaire, Dublin,
D23A/0347Dún Laoghaire–RathdownLodged 24 May 2023Retention
- GrantedAt this site
Permission for the Change of Use, refurbishment and extensions to the existing building to accommodate a…
12 Northumberland Avenue, Dún Laoghaire, Co Dublin
D19A/0152Dún Laoghaire–RathdownLodged 1 Mar 2019Apartments
- Granted30 m away
For the demolition of the existing kitchen and utility room and the construction of a new two storey…
14, Northumberland Avenue, Dun Laoghaire, Co. Dublin
D05B/0880Dún Laoghaire–RathdownLodged 6 Dec 2005Extension
- Granted30 m away
Permission for demolition of the existing single storey garage and the construction of a new single storey…
53 Mulgrave Street, Dún Laoghaire, Co Dublin A96 PX86
D19A/0138Dún Laoghaire–RathdownLodged 28 Feb 2019Extension
- Refused30 m away
New two storey four bedroom mews house with garage using existing vehicular access to the rear. The floor…
14, Northumberland Avenue, Dun Laoghaire, Co. Dublin
D05A/0652Dún Laoghaire–RathdownLodged 25 May 2005New dwelling
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
Permission is sought for the construction of a single storey extension to both the front and rear of the…
Marlfield House, Barrack Road, Dublin 18, D18 Y0X3
D18B/0460Dún Laoghaire–RathdownLodged 9 Apr 2019
- GrantedExtension
Permission is sought for construction of new single storey extension to the front and to the rear of existing…
344, Pearse Road, Sallynoggin, Dun Laoghaire, Co. Dublin
D12B/0213Dún Laoghaire–RathdownLodged 28 Jun 2012
- Awaiting decisionExtension
Permission is sought to convert an existing dwelling to a proposed 1 bedroom dwelling consisting of a rear…
95 Tower Street , Cork
2543755Cork CityLodged 28 Mar 2025
- GrantedExtension
Permission is sought for a single storey front extension, a single storey rear extension, extend first floor…
47, Rowans Road, Wedgewood,Sandyford, Dublin 18
D08B/0104Dún Laoghaire–RathdownLodged 18 Feb 2008
- GrantedExtension
Permission is sought for modification to existing dwelling house comprising one storey extension to front and…
35, Riverside Drive, Dublin 14
D11B/0268Dún Laoghaire–RathdownLodged 9 Aug 2011
- GrantedExtension
Permission is being sought to construct a new single storey extension to the front of existing dwelling along…
7, Pinewood Avenue, Dublin 11
WEB1588/24Dublin CityLodged 14 May 2024
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