Birley owns and runs 5 Hertford Street (5HS), a private members' club in Mayfair. Having found a dilapidated block of buildings in Shepherd Market, Mayfair, he raised £30 million to refurbish them; fashion designer Rifat Özbek was commissioned to design the interiors. 5 Hertford Street opened in June 2012 with a launch party attended by Mick Jagger, Kate Moss, and Daphne Guinness. The basement nightclub was named Loulou's after Birley’s late cousin, Loulou de la Falaise. Over the following five years, 5HS became a staple of London’s social scene, and is where Prince Harry and his fiancée Meghan Markle had their first date. The success of 5HS emboldened Birley to launch new membership-based venues.