TESCO has been granted permission to extend sales and storage areas at its store in the Holmbush Centre.
The plan includes an extra 305 square metres of sales floor and a mezzanine for storage.
There will also be an in-store community room, with internet access and computers, which community groups and classes will be able to book free of charge.
But this was not enough for councillor Peter Metcalfe, who said: “It’s a shame this massive organisation making massive profits can’t actually provide Shoreham and Southwick with a proper community centre.”
Despite confusion over the community room element of the plans, they were approved by Adur Council’s planning committee on Monday.