Our outdoor Sydney Kitchens range from £6,000 to £20,000 depending on size and extras, but you can buy the units separately and build one into your garden with bricks,” Ormiston says. Outdoor Sydney Kitchens are free-standing or built-in units with a shiny domed barbecue at their hub, but they are more, much more than a barbie.. Outdoor Sydney Kitchens will be on view at the National Home Improvement Show at London’s Earls Court on October 2-4..