Builder profile

Seamus O Brien & Sons Builders(Castl ebar)Ltd commencement pipeline.

20 commencement notices linked to this company builder. Counties: Mayo. Latest commencement date: 2025-05-08.

Last updated 1 Aug 2026 11:40 UTC owner-supplied commencement data

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This profile is published because the company builder appears on repeated, unsuppressed owner-export commencement notices. It is a public-display pipeline sample, not total-market coverage, and private home-address or personal-owner fields are not rendered.

Open current starts

20 notices

Commencement history

This profile renders company-builder data only. Private home addresses and owner personal details are not displayed.

Owner-supplied commencement export / CN0128293MO / 2025-05-08

Construct a dwelling house & attached garage with all associated site works and connections

Construct a dwelling house & attached garage with all associated site works and connections

Notice
Commencement Notice With Compliance Documentation
Commencement
2025-05-08
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 283 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P24/382
Owner-supplied commencement export / CN0126668MO / 2025-03-24

Dwelling house and all ancillary works

Dwelling house and all ancillary works

Notice
Commencement Notice with Opt Out Declaration
Commencement
2025-03-24
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 151 m²
Current commencementCommencement Notice with Opt Out DeclarationOwner exportOther commencement
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref 24282
Owner-supplied commencement export / CN0125907MO / 2025-02-28

Extension and alterations to domestic garage including a carport

Extension and alterations to domestic garage including a carport

Notice
Commencement Notice Without Compliance Documentation
Commencement
2025-02-28
Source
Owner-supplied commencement export; no public source URL
Location
Charlestown, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
units unknown / 93 m²
Current commencementCommencement Notice Without Compliance DocumentationOwner exportOther commencement
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P24/60365
Owner-supplied commencement export / CN0125231MO / 2025-01-31

Construction of a new single-storey extension to the rear of the property, refurbishment of the existing house, widening of existing entrance gates and all associated site works, drainage and landscaping

Construction of a new single-storey extension to the rear of the property, refurbishment of the existing house, widening of existing entrance gates and all associated site works, drainage and landscaping

Notice
Commencement Notice with Opt Out Declaration
Commencement
2025-01-31
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 71 m²
Current commencementCommencement Notice with Opt Out DeclarationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P23/60567
Owner-supplied commencement export / CN0121058MO / 2024-10-21

Demolition of the existing rear extension and construction of proposed extension to front of the existing dwelling, and alterations to fenestration on all elevations

Demolition of the existing rear extension and construction of proposed extension to front of the existing dwelling, and alterations to fenestration on all elevations

Notice
Commencement Notice with Opt Out Declaration
Commencement
2024-10-21
Source
Owner-supplied commencement export; no public source URL
Location
Claremorris, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 220 m²
Current commencementCommencement Notice with Opt Out DeclarationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P23/60523
Owner-supplied commencement export / CN0120048MO / 2024-09-25

Development of 29 no. dwellinghouses

Development of 29 no. dwellinghouses

Notice
Commencement Notice With Compliance Documentation
Commencement
2024-09-25
Source
Owner-supplied commencement export; no public source URL
Location
Foxford, Mayo
Council
Mayo County Council
Owner company
Cappaglen Developments Ltd
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
29 units / 3,401 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportHousing phase
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref 23/60300
Owner-supplied commencement export / CN0107900MO / 2023-12-05

ESB Substation building with switch room and all associated and ancillary works

ESB Substation building with switch room and all associated and ancillary works

Notice
Commencement Notice With Compliance Documentation
Commencement
2023-12-05
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Owner company
PCC Investments (IE) Ltd
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
units unknown / 23 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportOther commencement
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P23/462
Owner-supplied commencement export / CN0093805MO / 2022-09-30

Construction of Dwellinghouse and garage and connection to public foul sewer and all ancillary site services

Construction of Dwellinghouse and garage and connection to public foul sewer and all ancillary site services

Notice
Commencement Notice With Compliance Documentation
Commencement
2022-09-30
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 260 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportOne-off dwelling
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P21/615
Owner-supplied commencement export / CN0093189MO / 2022-09-07

Construction of a new house and associated works

Construction of a new house and associated works

Notice
Commencement Notice with Opt Out Declaration
Commencement
2022-09-07
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 191 m²
Current commencementCommencement Notice with Opt Out DeclarationOwner exportOne-off dwelling
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P21/571
Owner-supplied commencement export / CN0089372MO / 2022-05-25

Construction of a new dormer style two storey dwelling house with associated site development works

Construction of a new dormer style two storey dwelling house with associated site development works

Notice
Commencement Notice With Compliance Documentation
Commencement
2022-05-25
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 135 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportOne-off dwelling
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref 19127
Owner-supplied commencement export / CN0076884MO / 2021-06-03

Construct 2 no. detached dwellinghouses including all ancillary site works and services on site no's 7 & 8 (otherwise house no's 16 & 17)

Construct 2 no. detached dwellinghouses including all ancillary site works and services on site no's 7 & 8 (otherwise house no's 16 & 17)

Notice
Commencement Notice With Compliance Documentation
Commencement
2021-06-03
Source
Owner-supplied commencement export; no public source URL
Location
Turlough, Mayo
Council
Mayo County Council
Owner company
Cappaglen Developments Ltd
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
2 units / 280 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportOther commencement
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P17/1060 & P21/126
Owner-supplied commencement export / CN0074886MO / 2021-04-30

Construction of 21 m sq extension to existing dwelling House

Construction of 21 m sq extension to existing dwelling House

Notice
Commencement Notice Without Compliance Documentation
Commencement
2021-04-30
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Designer
Masterson Design Ltd
Units / floor
1 units / 21 m²
Current commencementCommencement Notice Without Compliance DocumentationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref 20324
Owner-supplied commencement export / CN0070086MO / 2020-11-09

Construction of 12 no. houses with associated site works

Construction of 12 no. houses with associated site works

Notice
Commencement Notice With Compliance Documentation
Commencement
2020-11-09
Source
Owner-supplied commencement export; no public source URL
Location
Westport, Mayo
Council
Mayo County Council
Owner company
Beckett Developments Ltd
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
12 units / 1,750 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportHousing phase
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P09/20900 & 19/960
Owner-supplied commencement export / CN0062178MO / 2020-03-04

Extension and renovation of existing dwellinghouse

Extension and renovation of existing dwellinghouse

Notice
Commencement Notice With Compliance Documentation
Commencement
2020-03-04
Source
Owner-supplied commencement export; no public source URL
Location
Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 188 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportOther commencement
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P19/19
Owner-supplied commencement export / CN0054371MO / 2019-07-24

New dwelling house, garage and on-site wastewater treatment system, access road and ancillary site development works

New dwelling house, garage and on-site wastewater treatment system, access road and ancillary site development works

Notice
Commencement Notice With Compliance Documentation
Commencement
2019-07-24
Source
Owner-supplied commencement export; no public source URL
Location
cASTLEBAR, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 242 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref 18708
Owner-supplied commencement export / CN0052831MO / 2019-06-14

Housing Development

Housing Development

Notice
Commencement Notice With Compliance Documentation
Commencement
2019-06-14
Source
Owner-supplied commencement export; no public source URL
Location
Westport, Mayo
Council
Mayo County Council
Owner company
Beckett Developments Ltd
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
18 units / 2,324 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportHousing phase
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref P18/250
Owner-supplied commencement export / CN0051858MO / 2019-05-15

Construction of new dwelling house, garage and wastewater treatment plant

Construction of new dwelling house, garage and wastewater treatment plant

Notice
Commencement Notice With Compliance Documentation
Commencement
2019-05-15
Source
Owner-supplied commencement export; no public source URL
Location
Breaffy, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 275 m²
Current commencementCommencement Notice With Compliance DocumentationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref 17945
Owner-supplied commencement export / CN0040405MO / 2018-06-22

new single storey 16.3m2 extension to dwelling

new single storey 16.3m2 extension to dwelling

Notice
Commencement Notice Without Compliance Documentation
Commencement
2018-06-22
Source
Owner-supplied commencement export; no public source URL
Location
Breaffy, Mayo
Council
Mayo County Council
Owner company
Halligan Architects Ltd
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 16 m²
Current commencementCommencement Notice Without Compliance DocumentationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref p17/575
Owner-supplied commencement export / CN0017101MO / 2016-06-15

CONSTRUCT NEW DWELLING HOUSE AND GARAGE TOGETHER WITH A NEW PROPRIETARY WASTEWATER TREATMENT UNIT, POLISHING FILTER, AND ALL ASSOCIATED SITE WORKS AND CONNECTION INTO EXISTING SERVICES

CONSTRUCT NEW DWELLING HOUSE AND GARAGE TOGETHER WITH A NEW PROPRIETARY WASTEWATER TREATMENT UNIT, POLISHING FILTER, AND ALL ASSOCIATED SITE WORKS AND CONNECTION INTO EXISTING SERVICES

Notice
Commencement Notice With Compliance Documentation
Commencement
2016-06-15
Source
Owner-supplied commencement export; no public source URL
Location
Castlebar, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / floor unknown
Current commencementCommencement Notice With Compliance DocumentationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL Open matched PlanningBrief lead Map Planning ref 15392
Owner-supplied commencement export / CN0012965MO / 2016-01-04

Single storey extension below 40 sqm to rear of existing property

Single storey extension below 40 sqm to rear of existing property

Notice
Commencement Notice Without Compliance Documentation
Commencement
2016-01-04
Source
Owner-supplied commencement export; no public source URL
Location
Breaffy, Mayo
Council
Mayo County Council
Builder
Seamus O Brien & Sons Builders(Castl ebar)Ltd
Units / floor
1 units / 40 m²
Current commencementCommencement Notice Without Compliance DocumentationOwner exportDomestic extension / garage
Source note: owner-supplied commencement export; no public source URL