Originally commissioned as a one-off Hogmanay special in 2013, the show proved a hit with critics and viewers and was recommissioned as a regular series.
The third series pulled in UK audiences of more than 1.8m, while in Scotland it seen by more than 400,000 – roughly a quarter share of the viewing audience – and also won the Best Comedy award at the 2017 Royal Television Society Scotland Awards.
Arabella Weir returns as Beth Baird alongside Alex Norton as husband Eric and Elaine C Smith as Christine, Doon Mackichan as Cathy and Jonathan Watson as her husband Colin.
Also returning are Jamie Quinn as the Bairds’ son Ian and Kieran Hodgson as his boyfriend Gordon.
Introduced in the last episode of series three, Graeme Stevely and Joy McAvoy will also be back as new neighbours Alan and Michelle.
Series four will see Beth and Eric celebrate 30 years of married bliss, while Christine will stress test the NHS with a temporary hospital stay, and the Bairds will receive a visit from Gordon’s parents Sandra and Graham, played by Maggie O’Neill (Shameless, EastEnders) and Alex Kirk (Bad Move).
Plus, there’s a whole new level of passive aggressive tension unleashed as Cathy jealously vies with new neighbour and rival Michelle…
Arabella Weir said: “The whole cast were thrilled at the very warm reception series three received across the UK.
“And for my part I’m over the moon to be pulling on Beth’s leggings again.”
Doon Mackichan added: “Cathy, as ever, will have a few surprises in her wardrobe and will deliver even more surprises in her neighbours’ living rooms.
“Series four is going to be fun.”
Steven Canny, Executive producer for BBC Studios Comedy, says; “Two Doors Down is a special show for us and I’m delighted that we are once again returning to Latimer Crescent.
“It’s made by an extraordinary group of people working at the top of their game.
“The writing, performances and craft skills are outstanding and I’m thoroughly looking forward to us finding new ways to torment poor Beth and Eric.”
Shane Allen, Controller Comedy Commissioning for the BBC commented: “The scripts for the new series are a laugh out loud riot, the cast are the cream of Scottish comedy talent and the audience continues to impressively grow and grow ”