What are the largest development sites in Castleknock?
178 development sites in Castleknock are a hectare or larger, as of 26 Sep 2026. The largest is public land in Castleknock, at 32.4 ha (publicly owned land).
From public registers, checked 26 Sep 2026. Updated nightly.
Sites of a hectare or more in Castleknock, largest first
Public land in Castleknock
Castleknock · Fingal · 32.41 ha · source
Publicly owned land
32.4 ha, Held by The Office of Public Works
Land in Castleknock
Castleknock · Fingal · 14.21 ha · source
On the RZLT map (3% land tax)
14.2 ha, On the 2027 draft RZLT map
Land in Castleknock
Castleknock · Fingal · 12.79 ha · source
On the RZLT map (3% land tax)
12.8 ha, On the 2027 draft RZLT map
Land in Castleknock
Castleknock · Fingal · 10.13 ha · source
On the RZLT map, no permission
10.1 ha, RZLT-liable and no live permission for 10+ homes on it
Diswellstown, Castleknock, Dublin 15
Castleknock · Fingal · 9.5 ha · source
Stalled build
224 homes; commenced 12 Nov 2014, no completion certificate, planned end Jul 2015
Diswellstown, Castleknock, Dublin 15
Castleknock · Fingal · 9.5 ha · source
Stalled build
224 homes; commenced 01 Jun 2015, no completion certificate, planned end Feb 2016
Public land in Castleknock
Castleknock · Fingal · 9.15 ha · source
Publicly owned land
9.2 ha, Held by Fingal County Council
Land in Castleknock
Castleknock · Fingal · 8.58 ha · source
On the RZLT map, no permission
8.6 ha, RZLT-liable and no live permission for 10+ homes on it
Land in Castleknock
Castleknock · Fingal · 8.55 ha · source
On the RZLT map (3% land tax)
8.6 ha, On the 2027 draft RZLT map
Land in Castleknock
Castleknock · Fingal · 8.52 ha · source
On the RZLT map (3% land tax)
8.5 ha, On the 2027 draft RZLT map
Public land in Castleknock
Castleknock · Fingal · 8.36 ha · source
Publicly owned land
8.4 ha, Held by The Minister for Education and Skills
Land in Castleknock
Castleknock · Fingal · 8.06 ha · source
On the RZLT map, no permission
8.1 ha, RZLT-liable and no live permission for 10+ homes on it
Public land in Castleknock
Castleknock · Fingal · 7.96 ha · source
Publicly owned land
8.0 ha, Held by Fingal County Council
Land in Castleknock
Castleknock · Fingal · 7.27 ha · source
On the RZLT map, no permission
7.3 ha, RZLT-liable and no live permission for 10+ homes on it
Land in Castleknock
Castleknock · Fingal · 7.22 ha · source
On the RZLT map, no permission
7.2 ha, RZLT-liable and no live permission for 10+ homes on it
Land in Castleknock
Castleknock · Fingal · 6.71 ha · source
On the RZLT map, no permission
6.7 ha, RZLT-liable and no live permission for 10+ homes on it
Site A
Castleknock · Fingal · 6.69 ha · source
Permitted, not started
971 homes granted 26 May 2023, expires 26 May 2028
Land in Castleknock
Castleknock · Fingal · 6.44 ha · source
On the RZLT map, no permission
6.4 ha, RZLT-liable and no live permission for 10+ homes on it
Public land in Castleknock
Castleknock · Fingal · 6.17 ha · source
Publicly owned land
6.2 ha, Held by Fingal County Council
Land in Castleknock
Castleknock · Fingal · 6.1 ha · source
On the RZLT map, no permission
6.1 ha, RZLT-liable and no live permission for 10+ homes on it
Public land in Castleknock
Castleknock · Fingal · 5.95 ha · source
Publicly owned land
5.9 ha, Held by Fingal County Council
Land in Castleknock
Castleknock · Fingal · 5.72 ha · source
On the RZLT map, no permission
5.7 ha, RZLT-liable and no live permission for 10+ homes on it
Land in Castleknock
Castleknock · Fingal · 5.52 ha · source
On the RZLT map, no permission
5.5 ha, RZLT-liable and no live permission for 10+ homes on it
Land in Castleknock
Castleknock · Fingal · 5.35 ha · source
On the RZLT map, no permission
5.3 ha, RZLT-liable and no live permission for 10+ homes on it
Land in Castleknock
Castleknock · Fingal · 5.3 ha · source
On the RZLT map, no permission
5.3 ha, RZLT-liable and no live permission for 10+ homes on it
Showing 25 of 178. See them all →
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More about Castleknock
- Is there development land for sale in Castleknock?
- Buildable found 17 sites in Castleknock with a public sign they could come to market, as of 26 Sep 2026: 5 council sites proposed for sale, 1 derelict site on the register and 11 stalled builds. These come from public registers, not agents' listings, so many are not advertised yet.
- How many development sites are there in Castleknock?
- Buildable tracks 562 development sites in Castleknock, as of 26 Sep 2026: every site with a public reason it could be built on or sold, from the councils' and national registers. They include 7 permitted schemes not started, 1 derelict site, 7 council land sales and 11 stalled builds.
- How much land in Castleknock is on the RZLT map?
- 499 ha of land in Castleknock is on the Residential Zoned Land Tax map, across 371 parcels (2027 draft RZLT map), as of 26 Sep 2026. 434 ha of it has no live permission for 10 or more homes. The tax is 3% of market value a year, collected by Revenue on maps the councils make.
- How much zoned land in Castleknock has no planning permission?
- 434 ha in Castleknock is zoned for housing, on the RZLT map and has no live permission for 10 or more homes: 352 parcels, as of 26 Sep 2026. Land on the map is liable for the Residential Zoned Land Tax of 3% of market value a year.
Data as of 26 Sep 2026. Sources: Council Residential Zoned Land Tax maps; Land Development Agency, Register of Relevant Lands; Planning applications (Department of Housing national planning data).
Cite this: What are the largest development sites in Castleknock? Buildable, data as of 26 Sep 2026. https://buildable.ie/q/largest-development-sites-castleknock
Facts from public registers, not advice. Every question · How it works