The planned Stevenage Costco megastore is now set to open in late 2018 – more than a year later than originally estimated.

The Comet: The Costco is set to replace the old John Lewis depot in Stevenage's Cavendish Road.The Costco is set to replace the old John Lewis depot in Stevenage's Cavendish Road. (Image: Archant)

The American wholesale giants’ scheme to turn the John Lewis depot site in Cavendish Road into a 14,030-square-metre superstore got the green light last March.

Costco’s James Cheesemore then announced a projected opening in the summer of 2017 – but today he told the Comet: “Our best estimation at this stage is to open the Costco warehouse club in the latter half of 2018.”

The Comet has requested clarification as to why this is.

The Costco plans for a members-only warehouse club with parking for 611 cars were unanimously approved by Stevenage Borough Council’s planning committee 12 months ago.

The public reaction at the time was enormous, and overwhelmingly positive – though neighbours were outraged.

Supporters of the store say it could bring up to 250 new jobs over the next five years, as well as new trade and investment into Stevenage.

Opponents, mostly living in Angotts Mead on the other side of Gunnels Wood Road, argue that the development could clog up the area with unmanageable traffic and pollution – a view shared by council leader Sharon Taylor at the time of the committee vote.

Under the Costco plans the building will retain its Grade II-listed idiosyncratic reinforced concrete roof, designed by the noted architect Felix Candela.

The main entry point will be on the site’s northern side, from Gunnels Wood Road. A junction with traffic lights will be created next to it.

The closest existing Costco store to Stevenage is its Watford branch, which also houses Costco UK’s head office.