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How many homes have planning permission but haven't started in Blanchardstown, Castleknock and Ongar?

3,363 homes in Blanchardstown, Castleknock and Ongar have planning permission but no start recorded, across 9 permissions, as of 25 Sep 2026.

From public registers, checked 25 Sep 2026. Updated nightly.

  • 3,363Homes not started
  • 9Permissions
  • 0Expiring within a year

The largest permitted schemes not started in Blanchardstown, Castleknock and Ongar

  1. Barberstown

    Ongar · Fingal · 29.59 ha · source

    Permitted, not started

    1243 homes granted 30 Mar 2023, expires 30 Mar 2033

  2. Site A

    Castleknock · Fingal · 6.69 ha · source

    Permitted, not started

    971 homes granted 26 May 2023, expires 26 May 2028

  3. Site B and Site C

    Castleknock · Fingal · 2.58 ha · source

    Permitted, not started

    352 homes granted 11 Jun 2024, expires 11 Jun 2029

  4. Porterstown

    Castleknock · Fingal · 4.39 ha · source

    Permitted, not started

    302 homes granted 24 Jun 2026, expires 24 Jun 2031

  5. Winterwood

    Castleknock · Fingal · 1.88 ha · source

    Permitted, not started

    175 homes granted 19 Sep 2025, expires 19 Sep 2030

  6. Clonsilla Inn

    Castleknock · Fingal · 2.08 ha · source

    Permitted, not started

    170 homes granted 21 Jan 2025, expires 21 Jan 2030

  7. Weavers Row

    Castleknock · Fingal · 2.23 ha · source

    Permitted, not started

    72 homes granted 19 Dec 2023, expires 19 Dec 2028

  8. Allendale House

    Ongar · Fingal · 1.37 ha · source

    Permitted, not started

    56 homes granted 26 Aug 2025, expires 26 Aug 2030

  9. Parkside Block 3

    Castleknock · Fingal · 0.66 ha · source

    Permitted, not started

    22 homes granted 17 Oct 2023, expires 17 Oct 2028

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The week's new sites: permission running out, council selling land, derelict or stalled. Each with its source. Free while in beta.

More about Blanchardstown, Castleknock and Ongar

Is there development land for sale in Blanchardstown, Castleknock and Ongar?
Buildable found 62 sites in Blanchardstown, Castleknock and Ongar with a public sign they could come to market, as of 25 Sep 2026: 26 council sites proposed for sale, 2 sites with planning permission running out or recently expired, 2 derelict sites on the register and 41 stalled builds. These come from public registers, not agents' listings, so many are not advertised yet.
How many development sites are there in Blanchardstown, Castleknock and Ongar?
Buildable tracks 1,665 development sites in Blanchardstown, Castleknock and Ongar, as of 25 Sep 2026: every site with a public reason it could be built on or sold, from the councils' and national registers. They include 9 permitted schemes not started, 13 derelict sites, 32 council land sales and 41 stalled builds.
What are the largest development sites in Blanchardstown, Castleknock and Ongar?
485 development sites in Blanchardstown, Castleknock and Ongar are a hectare or larger, as of 25 Sep 2026. The largest is public land in Blanchardstown-Mulhuddart, at 38.9 ha (publicly owned land).
How much land in Blanchardstown, Castleknock and Ongar is on the RZLT map?
1,104 ha of land in Blanchardstown, Castleknock and Ongar is on the Residential Zoned Land Tax map, across 1,093 parcels (2027 draft RZLT map), as of 25 Sep 2026. 991 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.

Data as of 25 Sep 2026. Sources: Planning applications (Department of Housing national planning data).

Cite this: How many homes have planning permission but haven't started in Blanchardstown, Castleknock and Ongar? Buildable, data as of 25 Sep 2026. https://buildable.ie/q/homes-permitted-not-built-dublin-15

Facts from public registers, not advice. Every question · How it works