Amendments to planning permission dated 4th September 2020 (RN:20/03854/FULL) for Variation of Condition 1 of planning permission dated 23 April 2019 (RN 18/10640/FULL) for, 'Demolition and replacement of existing fourth floor, demolition of existing plant room, and erection of a single storey roof extension at fifth floor and rear extension at second to fifth floor levels in connection with existing office (Class B1) use, provision of new main office entrance, flexible use of part ground and basement floor for either retail or office use (Class A1/B1), creation of roof terrace at fifth floor level, provision of cycle parking spaces and facilities, roof plant and associated external alterations, including replacement windows. Namely,the removal of decorative window bars at fourth floor level on all elevations.

Amendments to planning permission dated 08 June 2021 (21/02350/FULL) (which itself was a variation of condition 1 of planning permission dated 28 March 2020 (RN:20/01191/FULL)) for demolition of the existing building behind a retained front facade. Excavation of a basement with front and rear light wells, erection of a rear extension at lower ground floor, a single storey closet wing extension at first floor level and the alterations to the roof to the rear. Associated alterations to the front stairs to facilitate the basement excavation. Replacement windows to front façade and changes to rear windows. Namely, changes to the rear garden terrace adjusted to suit the landscaping scheme; front steps to be rebuilt straight; existing front gates to be removed be replaced with a new pedestrian gate and bi-fold driveway gate; rear closet wing to increase in height by approximately 120mm, railings to the rear to have straight mild steel spindles (painted black); wall beneath entrance stair to be removed to allow for the excavation of the basement; and existing party wall to No.73 Carlton Hill to be retained.

Amendments to planning permission dated 20 June 2016 (RN: 15/10444) for: Variation of Condition 1 of planning permission dated 8 December 2011 (RN10/01741/FULL) for development of 55-91 Knightsbridge (including retention of Knightsbridge and William Place facades) to provide retail (Class A1) at basement and ground floor levels, office ( Class B1) at part ground, first, and second floor levels and residential flats at part ground, part first,part 2nd and 3rd to 5th floor levels. Off street servicing and new sub basement car park. Removal and replacement of existing tree on William Street. Demolition of 1-2 William Street and its replacement with a redesigned building with internal linkages to 55-91 Knightsbridge. Restoration and repair of external facades and roofs to 3-7 William Street including reinstatement of original roof profile at 4 William Street, conversion of 1st to 3rd floor levels of 3 and 4 William Street for residential purposes ( Class C3). Namely, the substitution of new drawings to allow minor material amendments comprising a revised number and mix of residential units; the provision of a terrace for a residential unit on the western end of the building; erection of a lift shaft to the rear of 4 William Street; alterations to shopfront of Nos. 3 - 4 William Street; extension at 4th floor level to the rear of Knightsbridge; and reconfiguration of the fenestration. Namely, amendment to the external air vent at 4 William Street.