You can now book a one-hour, fully-accessible tour of the State Apartments of the Speaker’s House, which includes the Grand Staircase, the Crimson Drawing Room, the State Dining Room, and the State Bedroom. The tour starts and finishes in Westminster Hall which you are welcome to explore afterwards.

See here for full details and booking: https://ukparliament.seetickets.com/timeslot/the-state-apartments-of-speaker-s-house-tour