Office, which opened last November a 1,300-square-foot flagship store on London’s Oxford Street, plans to open 20 more regular retail stores in the UK in 2006. Meanwhile, two former managers of Office plan to launch a new retail concept, called Sniff, featuring a combination of commercial and outlandish brands, including Birkenstock. The first Sniff store will open next month on London’s Great Titchfield Street. Four others should follow in the next couple of years. The project is the creature of Sean Farrell, former chief executive of Office, and Lynsey Hand, the chain’s former buyer.