Costain Group

Costain Group plc

Type	Public limited company (: )
Industry	Construction, Civil engineering
Founded	1865
Headquarters	Maidenhead, United Kingdom
Key people	Dr Paul Golby, Chairman Andrew Wyllie, CEO
Revenue	£1,658.0 million (2016)
Operating income	£41.3 million (2016)
Net income	£26.4 million (2016)
Number of employees	4,000 (2017)
Website	www.costain.com

Costain Group plc is a British construction and civil engineering company headquartered in Maidenhead. It was part of the original Channel Tunnel consortium and is involved in Private Finance Initiative projects.

The business was founded in 1865 when Richard Costain and his future brother-in-law, Richard Kneen, left the Isle of Man and moved to Liverpool as jobbing builders. The partnership lasted until 1888 when Richard Kneen left and Richard Costain's three sons (Richard, William and John) joined him. By the time of the First War, Costain had expanded through Lancashire and into south Wales where it built houses for munitions workers.

After the First World War, Costain began to develop housing estates in Liverpool on its own account, primarily to offer continuity of employment to its workforce. With housing sites in Liverpool in short supply, Richard Costain sent his son William down to London to find new sites. He purchased the Walton Heath Land Company and in 1923 the separate business of Richard Costain & Sons was formed. Several executive estates in the Croydon area were developed in the mid-1920s. In 1929 William died: the other two brothers remained in Liverpool and William’s son, Richard Rylands Costain, was sent to run the London Company. Under him, Richard Costain & Sons expanded its housing building large estates all around London, the largest being a site for 7,500 homes in South Hornchurch, started in 1934. Perhaps the best-known development of all was Dolphin Square completed in 1937. In 1933 the London-based Richard Costain was floated on the ; the Liverpool business was not part of the flotation. By then, Costain had completed over 4,000 houses in the London area, some at prices up to £4,000. Costain continued to expand its private housebuilding and it was described as "one of the largest speculative housebuilders and estate developers in this country before the war."

Following the flotation, Costain moved into civil engineering and worked first on the Trans-Iranian Railway and then at Abadan, Iran for BP. Losses on the railway, on Beckton sewage works and the costs of Dolphin Square caused financial problems, and Costain had to look for alternative funds when Barclays withdrew its overdraft facilities.