National Storage Mechanism | Additional information

Costain Group PLC

29 July 2025

Investor Presentation via Investor Meet Company

Half Year 2025 Results Investor Q&A

Costain Group PLC ("Costain") announces that Alex Vaughan, CEO, and Helen Willis, CFO, will be hosting an investor Q&A session relating to the 2025 Half Year Results via Investor Meet Company on 21 August 2025 at 10.00am BST.

The Q&A session is open to all existing and potential shareholders. Questions can be submitted pre-event via the Investor Meet Company dashboard up until 9:00am on 20 August 2025 or at any time during the live presentation.

Investors can sign up to Investor Meet Company for free and add to meet Costain via:

https://www.investormeetcompany.com/costain-group-plc/register-investor

Investors who already follow Costain on the Investor Meet Company platform will automatically be invited.

Costain will issue its results for the six months ended 30 June 2025 on 20 August 2025.

Enquiries

Investors and analysts Matt Jones, Costain	matt.jones@costain.com +44 (0) 7860 922341
Financial media - Headland	costain@headlandconsultancy.com
Andy Rivett-Carnac	+44 (0) 7968 997 365
Charlie Twigg	+44 (0) 7946 494 568

Notes to editors

Costain improves people's lives by creating connected, sustainable infrastructure that enables people and the planet to thrive. Through the delivery of predictable, best-in-class solutions across the transport, water, energy and defence markets, we are creating a sustainable future and securing a more prosperous, resilient and decarbonised UK.

By bringing together our unique mix of construction, consultancy, engineering and digital services, we work strategically with our customers and suppliers to meet critical national needs. Together, our people transform the performance of the infrastructure that connects, protects and powers people's lives .

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