Produced by Irish building magazine with Linesight the ‘Top 50 League Table of Irish Main and Specialist Contractors’ reveals that average turnover in 2024 rose by 17.7% compared to 2023. Total combined turnover increased from €15.6 billion to €18.4 billion—highlighting confidence, strong project pipelines, and a sector that is scaling strategically both at home and abroad.

Sisk retains its lead position in the overall rankings, posting a turnover of €2.75 billion, including €1.18 billion from the domestic market. However, what is particularly striking in this year’s table is the continued rise of Ireland’s specialist contractors.

Mercury Engineering, for example, ranks second overall with €1.81 billion, driven by its international expansion and deep expertise in data centres and life sciences. Winthrop Technologies and Jones Engineering Group follow close behind, both exceeding €1 billion in turnover.

This crossover underscores the increasing value of technical expertise in Ireland’s export-driven construction economy—and positions specialist contractors not only as subcontractors, but as lead players in major project delivery.

“This year’s Top 50 league table paints a picture of a confident, capable, and globally active Irish construction industry. With turnover reaching €18.4 billion and an average year-on-year increase of 17.7%, it’s clear that firms are not only recovering—they’re evolving. Innovation is now central to that evolution. The rise of MMC, digital collaboration, and offsite solutions shows that contractors are not just delivering projects—they’re reshaping how we build. The growing influence of specialist firms alongside main contractors reflects a high-performance, future-focused sector that’s embracing smarter, faster, and more sustainable delivery,” said: Colin Walsh, Media Director, Irish building magazine.

Stephen Ashe, VP Global Delivery Excellence, Linesight said: “There are clear economic headwinds facing the Irish construction sector—from planning delays and power constraints to the looming impact of tariffs. But there are also real opportunities. We have a skilled workforce, global clients who value Irish expertise, and growing demand in high-tech and mission-critical sectors. Attracting, training, and retaining the right talent is fundamental to building long-term resilience. Without it, we risk not only losing investment but also losing our competitive edge.”

Capability Building for a Changing Market

The league table also shows a sector investing in its future. In 2024, the Top 50 Contractors recorded a combined €10.06 billion in home turnover and €8.33 billion in foreign turnover. This impressive balance reflects a well-developed export capacity and the ability to deliver complex, high-value projects across Europe.

Sisk exemplifies this dual strength. Operating in over 15 countries and delivering major projects in data, life sciences, infrastructure and healthcare, the company is combining international expansion with innovation at home.

“Financial performance is only one part of the story. At Sisk, we’re equally focused on people, innovation, and long-term industry impact. Whether it’s our investment in MMC and digital transformation or our commitment to developing talent, we believe construction must lead—not just keep up. In a market shaped by global uncertainty, the key to resilience lies in realistic, visible project pipelines and a collaborative approach to building the capacity Ireland needs,” said Paul Brown, CEO, John Sisk & Son.

The increasing shift to foreign activity highlights a broader trend: in the face of ongoing uncertainty in Ireland’s public infrastructure pipeline—driven by delays in planning, consents, and the unattractiveness of public procurement—contractors are turning toward more predictable and well-funded private sector clients abroad. As Paul Sheridan, Director of Main Contracting Services at the CIF noted recently: “The construction industry has the capacity to deliver the necessary infrastructure to support housing and foreign direct investment.”

“The real constraints are associated with bottlenecks in planning, consents, lack of multi-annual funding and the unattractiveness of Public Procurement. There is huge uncertainty surrounding Government Investment and the public delivery of infrastructure in Ireland. This uncertainty is driving contractors towards clients who they have confidence whether home or increasingly in other jurisdictions in the UK, Europe, Canada and the US.”

Looking Ahead

The 2024 Top 50 confirms that Irish construction is not only growing—it is evolving in its approach to risk, opportunity, and innovation. From digital modelling and data-led safety to new technologies in low-carbon materials and offsite building, the sector is adapting to the demands of modern delivery, all while becoming more inclusive and diverse.

Yet challenges persist. Skills shortages, planning delays, and grid constraints continue to test resilience. As the sector looks forward, it will require continued investment in people, smarter policy support, and deep collaboration across the value chain to unlock its full potential.

In that context, the Top 50 Contractors are more than market leaders. They are industry shapers—redefining what construction success looks like in Ireland and beyond.

Top 5 Main Contractors (by 2024 turnover):

1. John Sisk & Son Ltd – €2.75bn

2. Collen Construction – €1.15bn

3. John Paul Construction – €736m

4. Walls Construction – €630m

5. PJ Hegarty & Sons – €571m

Top 5 Specialist Contractors (by 2024 turnover):

1. Mercury Engineering – €1.81bn

2. Winthrop Technologies – €1.58bn

3. Jones Engineering – €1.28bn

4. Kirby Group Engineering – €750m

5. Dornan Engineering – €734m

You can read interviews with Ireland’s ‘Leaders in Construction’ in the latest issue of Irish building and check out which companies made it onto the Top 50.

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