Director Declaration

COSTAIN GROUP PLC

("Costain" or the "Company")

Board Notification - External Directorship

Costain has been informed that, with effect from 11 July 2016, Alison Jane Wood, a Non-Executive Director of the Company, Chair of Costain's Remuneration Committee and member of the Company's Audit and Nomination Committees, has been appointed as a Non-Executive Director of TT Electronics plc, a company listed on the London Stock Exchange. Alison will also be appointed, with effect from 31 August 2016, as Chairman of the Remuneration Committee of TT Electronics plc and a member of their Audit and Nominations Committees.

This announcement is made in accordance with Listing Rule 9.6.14.

11 July 2016

Enquiries:

Costain Group PLC Tel: 01628 842444Tracey Wood, Company Secretary