Costain Group

Costain Group plc

Company type	Public limited company
Traded as	LSE: COST
Industry	Construction, civil engineering
Founded	1865
Headquarters	Maidenhead, England, UK
Key people	Paul Golby, Chairman Alex Vaughan, CEO[1]
Revenue	£1,332.0 million (2023)[2]
Operating income	£26.8 million (2023)[2]
Net income	£22.1 million (2023)[2]
Website	www.costain.com

Costain Group plc is a British construction and engineering company headquartered in Maidenhead, England.

It was established by Richard Costain and Richard Kneen in 1865, initially operating as builders in and around Lancashire. During the early 20th century, Costain expanded geographically, its main activities comprising housebuilding and mining. A separate London-based company was formed in 1923 by the Costain family and was floated on the London Stock Exchange ten years later. Shortly thereafter, Costain moved into civil engineering activities, such as its work on the Trans-Iranian Railway. During the Second World War, Costain helped build several Royal Ordnance Factories, airfields, and worked on the Mulberry harbour units.

By the start of the 1970s, Costain was building around 1,000 houses per year. During this decade, it benefitted greatly from a construction boom in the Middle East; profits increased from little more than £1m per year to £47m within a decade.^[3] During the 1980s, Costain invested its resources into coal mining, international housing and commercial property; however, both the housing and property markets, and thus the business, were heavily impacted by the early 1990s recession, which led to sell-offs and cutbacks, especially housebuilding, which reoriented Costain towards the construction sector. Despite the company's fiscal difficulties, it (as part of the TransManche Link consortium) completed construction of the Channel Tunnel, which was at the time the most expensive construction project ever proposed at a final cost amounted to £9 billion (equivalent to £22.6 billion in 2023). Into the 21st century, it has worked on numerous complex civil engineering and commercial construction projects and has been involved in various Private Finance Initiative (PFI) schemes.

Costain's operations have occasionally been a subject of controversy. It used to be a subscriber to the United Kingdom's Consulting Association, which was an illegal construction industry blacklist; legal action was taken against the company in this matter during the 2010s. In 2019, Costain was suspended from the UK Government's Prompt Payment Code after failing to pay suppliers on time.