AGM Trading Update

Ahead of today's Annual General Meeting ("AGM"), Costain Group PLC ("Costain" or the "Group") announces an update on trading for the period 1 January 2025 to date ("the period").

Costain confirms that trading for the period is in line with Board expectations. The Group remains on track to meet its 4.5% adjusted operating margin run rate target during 2025 and continues to expect its 2025 full year net cash position to be in line with current market expectations of around £180m.

Costain retains a high-quality forward work position that aligns with its strategic plans. The successful execution of its strategy delivered a record increase in the forward work position of £1.5bn to £5.4bn in 2024. In 2025, the Group remains busy bidding further new work across all sectors and broadening its customer mix. In particular, wins in the period include new contracts in Nuclear Energy:

• Urenco: a programme delivery partner framework to deliver new and upgraded infrastructure at its Cheshire site and is Costain's first contract with Urenco as it expands capacity as a key enabler for the UK's decarbonised energy system;
• Urenco: an additional design services FEED for the first commercial scale high-assay low-enriched uranium facility to be built in the UK;
• Sizewell C: a ten-year framework to provide engineering, project delivery and quality control expertise to support the construction of the new nuclear power station, expected to be one of the biggest net zero projects in the UK; and
• Department for Energy Security & Net Zero (DESNZ): provision of technical expertise and strategic consultancy services on the Nuclear and Emerging Technologies lots within the Energy and Net Zero Professional Services Framework.

While mindful of the macro-economic backdrop, through its focus on critical national needs Costain continues to improve the quality of its contract portfolio and deliver on its targets, and the Board remains confident in the Group's strategy and growth prospects.

As part of the AGM presentation, Costain will provide a short business update drawing on information published on 11 March 2025. There will be no new material information in the presentation further to that of 11 March 2025 and today's announcement.