A few years ago some City speculators spotted they were more likely to get planning permission if their new skyscraper included a free public roof terrace . Free access to elevated views is always a winner in my book. So yesterday I went up a few. This was all on-the-hoof so I didn't go up the big three because they expect you to book in advance. Sky Garden at The Fenchurch Building, aka The Walkie-Talkie Opened January 2015, 35th-37th floors, blogged here You have to book at least three weeks ahead, but yesterday 'Closed For Private Event'. Horizon 22 at 22 Bishopsgate Opened September 2022, 57th-58th floor, blogged here Tickets released on Mondays, they go fast but ridiculously early slots are often available. The Lookout at 8 Bishopsgate Opened August 2022, 50th floor, blogged here Tickets released on Mondays, current availability in four days time, but Horizon 22 is better. I went instead to the walk-straight-ins, starting with the newest.…