Sainsbury’s is to open its first dark store, in east London, to meet demand for its growing online grocery arm.

The online fulfilment centre will open in Bromley-By-Bow, east London “within the next few years”, Sainsbury’s said. The dark store will help it meet “growing demand for its online grocery service in London and the Southeast”.

When fully operational, the 185,000 sq ft facility will allow Sainsbury’s to serve an additional 20,000 customers each week.

The grocer said the move follows Sainsbury’s online grocery business reaching the milestone of annualised sales of £1bn in September.

Sainsbury’s online delivers to more than 190,000 customers every week with sales growth of 15% per year, the grocer said.

Sainsbury’s director of online, digital and cross-channel Jon Rudoe said: “We work hard to ensure we deliver the very best service to our customers and the opening of the new centre will enable us to maintain this. The site will be purpose built with the Sainsbury’s customer in mind and will support our existing store-based operation, something that will continue to be the foundation of our online grocery business.

“I am confident that this new facility will take our online grocery operation to the next level and put us in a perfect position to meet the growing demand in London and the Southeast.”

The grocer has until this point served its online customers by picking products from supermarkets. Sainsbury’s said that, while it will continue to pick and handle the “substantial majority of online orders in our supermarkets, the Bromley-by-Bow store will help the retailer keep pace with demand in the capital”.