Sisk has appointed Brian Comaskey as managing director of its Ireland East business unit and Diarmuid O’Sullivan as managing director of a newly established Energy Business Unit. The appointments give separate leadership to two growth priorities: construction activity in Dublin and delivery of projects supporting the energy transition.
Who are Sisk’s two new managing directors?
| Executive | New role | Reports to | Primary focus |
|---|---|---|---|
| Brian Comaskey | Managing director, Ireland East business unit | Steven McGee, COO, Sisk Construction | Residential and commercial growth in Dublin, alongside Sisk’s healthcare, energy and infrastructure strategy |
| Diarmuid O’Sullivan | Managing director, Energy Business Unit | Leo Martin, COO, Sisk Infrastructure | Dedicated leadership for energy-transition delivery |
The appointments were reported by The Irish Post on 15 October 2026. They affect different parts of Sisk’s organisation: Comaskey leads a geographic business unit within Sisk Construction, while O’Sullivan heads a new sector-focused unit within Sisk Infrastructure.
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Brian Comaskey’s Ireland East mandate
Comaskey takes responsibility for Sisk’s Ireland East business unit, with Dublin as the main area identified in the announcement. His remit covers the opportunity to expand residential and commercial work while contributing to the company’s broader activity in healthcare, energy and infrastructure.
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Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →He has been with Sisk for 22 years. Reporting to Steven McGee, chief operating officer for Sisk Construction, Comaskey will lead the Ireland East operation within the construction division’s reporting structure.
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“I am delighted to be appointed as the Managing Director of the Sisk, Ireland East business unit,” Comaskey said.
He described the role as an opportunity to “grow and develop further in the residential and commercial space in Dublin” and to “play a key role in the overall company strategy in healthcare, energy and infrastructure.” His statement sets out a strategic direction, but the announcement does not provide a project pipeline, investment figure, headcount target or forecast for the unit.
Diarmuid O’Sullivan and the new Energy Business Unit
O’Sullivan becomes managing director of a newly established Energy Business Unit. The unit is intended to give energy-transition projects dedicated leadership and focus rather than treating them only as part of a wider portfolio.
He reports to Leo Martin, chief operating officer of Sisk Infrastructure. That line places the new unit within the infrastructure side of the business and distinguishes its remit from Comaskey’s Ireland East construction responsibilities.
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O’Sullivan described the energy transition as a long-term opportunity for Sisk, pointing to the company’s existing experience and capability as a basis for becoming a leading delivery partner. He also linked the move toward cleaner and more secure energy with new opportunities for the business.
“I am delighted to be taking on this new challenge and proud to be part of this great Sisk team,” O’Sullivan said. He added that establishing a dedicated business unit provides “the leadership and focus required to build a sustainable business in this sector.”
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- Author: Bungay Stanier, Michael.
- Publisher: Page Two
- Pages: 244
- Publication Date: 2016-02-29
- Edition: 1
How the appointments fit Sisk’s growth strategy
Taken together, the appointments separate two routes to growth:
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- Geographic and market expansion: Comaskey’s Ireland East role is centred on Dublin’s residential and commercial market, while supporting Sisk’s work across healthcare, energy and infrastructure.
- Sector specialisation: O’Sullivan’s role creates a dedicated structure for energy-transition projects and the capabilities needed to deliver them.
- Clear executive accountability: The reporting lines connect the appointments to the chief operating officers of Sisk Construction and Sisk Infrastructure respectively.
The company has not published financial projections, additional staffing numbers, project values or measurable performance targets alongside the appointments. The stated rationale is strategic: stronger local leadership in Ireland East and concentrated leadership for a growing energy-transition market.
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What is established about the announcement
- Brian Comaskey is managing director of Sisk’s Ireland East business unit.
- Diarmuid O’Sullivan is managing director of the newly established Energy Business Unit.
- Comaskey has 22 years’ service with Sisk and reports to Steven McGee.
- O’Sullivan reports to Leo Martin and is responsible for the energy-focused unit.
- The announcement gives strategic objectives but no quantified business-impact forecast.
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