18, Northumberland Avenue, Dun Laoghaire, Dublin, A96K793
Alterations and extensions to a house in Dun Laoghaire, including a new basement extension and a rear extension.
D26A/0155/WEB · Dun Laoghaire Rathdown County Council · Lodged 1 March 2026
- Reference
- D26A/0155/WEB
- Authority
- Dun Laoghaire Rathdown County Council
- Register status
- Decided
- Type
- Permission
- Received
- 1 March 2026
Summary
AI-generatedThe development consists of alterations to a previously permitted scheme. Works include the removal of an existing flat roof basement extension and a two-storey rear annex, and the construction of a replacement basement extension, a new rear extension at upper ground floor level, and a replacement bathroom extension at first floor level.
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: alterations to the proposed development permitted under register reference no. D24a/0551/web. Works include i) the removal of an existing flat roof extension at basement level, ii) removal of existing two storey rear annex structure, iii) construction of a flat roof replacement basement extension with 1 no. Roof light, iv) construction of a new rear extension with 1 no. Roof light at upper ground floor level, v) construction of a replacement bathroom extension at first floor level, vi) internal modifications and general upgrades, vii) all associated site, landscaping and services 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 | 39 m |
| 34 Northumberland Avenue, Dunlaoughaira, Co Dublin | Dec 2025 | €1,900,000 | 42 m |
| 32 Mulgrave St, Dun Laoghaire, Dublin | Jul 2025 | €880,000 | 73 m |
| 30 Mulgrave St, Dun Laoghaire, Dublin | Nov 2025 | €1,800,000 | 79 m |
| 2 Patrick Court, Patrick St, Dun Laoghaire | Apr 2026 | €572,000 | 105 m |
| 3 Patrick Court, Patrick St, Dun Laoghaire | Jun 2026 | €585,000 | 106 m |
| The Coach House, Sydenham Mews, Corrig Avenue | Jan 2026 | €750,000 | 127 m |
| 21a Mulgrave St, Dun Laoghaire, Dublin | Feb 2026 | €840,000 | 129 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 received1 March 2026
- Decision due4 June 2026
- Decision issued3 June 2026
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
Planning permission for — Demolition of existing flat roof extension to rear at Basement level
18, Northumberland Avenue, Dun Laoghaire, Dublin, A96K793
D24A/0551/WEBDún Laoghaire–RathdownLodged 24 Jul 2024Extension
- Refused30 m away
Permission for a new front garden design, car entrance and modifications of existing cast iron railings and…
16 Northumberland Avenue, Dún Laoghaire, Co Dublin
D16A/0448Dún Laoghaire–RathdownLodged 21 Jun 2016Alterations
- Granted30 m away
Planning permission is sought for replacement of upvc windows with painted hw sash windows to front…
Sonas, 16 Northumberland Avenue, Dun Laoghaire, Co Dublin, A96Y625
D22A/0706Dún Laoghaire–RathdownLodged 21 Sept 2022Extension
- Awaiting decision40 m away
Permission is sought for the change of use from a multi-occupancy building containing three apartments back…
15, Northumberland Avenue, Dun Laoghaire, Co. Dublin, A96EH42
D25A/0943/WEBDún Laoghaire–RathdownLodged 8 Dec 2025Change of use
- Granted40 m away
Permission is sought for alterations and additions to include (1) construction of a single storey extension…
15, Northumberland Avenue, Dun Laoghaire, Co. Dublin
D16A/0768Dún Laoghaire–RathdownLodged 4 Apr 2017Apartments
- Granted40 m away
Permission for demolition of rear 2 storey return (ca 34 sqm) and replacement with a single storey extension…
21 Northumberland Avenue, Dún Laoghaire, Co Dublin
D18B/0177Dún Laoghaire–RathdownLodged 17 Apr 2018Extension
- Granted40 m away
The development will consist of alterations to the previously granted permission D23B/0521 with a reduced…
34, Northumberland Ave, Dun Laoghaire, A96Y7H1
D26B/0256/WEBDún Laoghaire–RathdownLodged 27 Apr 2026Alterations
- Granted40 m away
(1) Removal of part of existing railings to Northumberland Avenue to provide vehicular access. (2) Provision…
34, Northumberland Avenue, Dun Laoghaire, Co. Dublin.
D04A/0641Dún Laoghaire–RathdownLodged 10 Jun 2004Alterations
Related developments
Similar applications
Ranked by what these developments actually propose, not by matching words — so you can see how comparable applications were decided.
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The development will consist of: Demolition of existing rear single storey extension. Proposed single storey…
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The development will consist of: (i) demolition of part single part two-storey extensions to side and the…
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