This staircase, designed by Thomas Griem, not only connects the lower and upper floors of this penthouse but cleverly provides library and storage along the way. Constructed entirely out of Oak and sturdy in appearance, the library offers a reading niche on its lower level and supports a minimal white & clear glass staircase that bridges to the upper level of the apartment hewn out of the roof space of the grade one listed St Pancras Hotel. Photographer: Philip Vile