Plans to turn the John Lewis depot site in Stevenage’s Cavendish Road into a 14,030-square-metre Costco megastore were given the green light on Tuesday – and, although many are delighted, neighbours are outraged.

The plan was unanimously approved by Stevenage Borough Council’s planning committee even though council leader Sharon Taylor argued against it.

The public reaction on social media when the Comet reported the news online on Tuesday night was enormous – and overwhelmingly positive.

James Cheesemore, Costco UK’s real estate manager, said: “We are very excited to be investing in Stevenage. Our current estimation is to open in the summer of 2017.”

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 the town.

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.

Beth Gray said after the decision: “Obviously we are extremely disappointed. We asked a number of questions about traffic, pollution and more and it’s all just been totally ignored.”

Catherine Baker, who also lives in Angotts Mead, added: “We haven’t been consulted as much as we should have been. Costco have a store in Sunbury they opened recently, and they leaflet-dropped 750 homes and did a big public exhibition. We haven’t been consulted at all.”

Tuesday’s meeting opened with a presentation against the plan delivered by Philip Woodward.

He said: “We’ve been let down by Costco and our own councillors. The people who support it, where do they live? The other side of Stevenage. It worries me immensely that people actually consider this in the first place.”

Ian Dix from Vectos, which carried out the planning survey attached to Costco’s application, stressed his own Stevenage connections, then said: “The site we’re looking at is not a greenfield site, but a brownfield site. It does generate traffic now.

“The assessment we’ve done is based on other Costco sites.”

Herts County Council development engineer Manjinder Sehmi added that predicted traffic flow was based on comparable sites in Herts, Kent and elsewhere.

Councillor Taylor, who represents Symonds Green but does not sit on the planning committee said: “I congratulate the objectors to this application. Angotts Mead is a quiet, self-contained residential area.

“You can imagine their horror that it is not named anywhere in the application as if it did not exist.”

Just before the vote Councillor Michelle Gardner, who represents Bandley Hill, said: “If I lived in Angotts Mead I might well feel I don’t like what’s going on, but looking at the law I don’t see how we can vote against it.”

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.