Variation of condition 1, condition 4 (parts a, d, e, g, h, I, j, k) and condition 5 (parts i, iv, v, vii, viii, x) and the removal of condition 4 (parts b, c, f), 5 (parts ii, iii, vi and ix) and 8 of listed building consent dated 3 December 2020 (RN: 20/03709/LBC), which itself varied Condition 1 of listed building consent dated 3 April 2018 (RN: 17/10530/LBC) for 'Alterations to the existing building including removal of existing roof top plant and extension to create an additional storey at fifth floor with tiled mansards and lead clad dormer windows to front and rear; a single storey extension at fourth floor comprising a glazed dome above the existing rear bow; installation of plant at roof level; partial infilling of lightwell adjacent to Gwydyr House; facade cleaning and other facade repair; internal alterations including reconfiguration, fabric removal, and refurbishment works on all floors; refurbishment of meetings rooms, entrance reception and offices; installation of new heating and cooling equipment; provision of a glazed research pod in the library; installation of light-boxes above the central stair and library, and other associated works'. Namely, to allow amendments to the approved scheme that include the installation of a proposed smoke extract system to mechanically ventilate new smoke lobbies to the secondary staircase; the removal of the lift access to the new fifth floor level and associated rooftop overrun; internal alterations at fourth and fifth floor levels; and alterations to ducting at roof level.

Variation of Condition 1 of listed building consent dated 12 December 2018 (RN: 18/05558/LBC) for alterations to the existing building at 152-153 Strand including demolition of rear facade and erection of ground to fourth floor rear extension, removal and replacement of existing roof, to include new windows, restoration of front facade, windows and shopfront, insertion of new internal atria, demolition of existing floorplates, stairs and building fabric and installation of new floors and partitions, and associated internal and external alterations, all in connection with the use of the building as flexible office and/or educational (Class B1 and/or Class D1) use with flexible retail and/or restaurant (Class A1 and/or Class A3) space at part basement and ground floor level namely; the removal of stone fascia on 152-153 Strand and its replacement with a timber fascia of the same design.

Variation of condition 1 of listed building consent dated 3 April 2018 (RN: 17/10530/LBC) for 'Alterations to the existing building including removal of existing roof top plant and extension to create an additional storey at fifth floor with tiled mansards and lead clad dormer windows to front and rear; a single storey extension at fourth floor comprising a glazed dome above the existing rear bow; installation of plant at roof level; partial infilling of lightwell adjacent to Gwydyr House; facade cleaning and other facade repair; internal alterations including reconfiguration, fabric removal, and refurbishment works on all floors; refurbishment of meetings rooms, entrance reception and offices; installation of new heating and cooling equipment; provision of a glazed research pod in the library; installation of light-boxes above the central stair and library, and other associated works'. Namely, to vary the approved drawing numbers to make amendments including a reduction in size of the glazed dome and automatic opening vent, increase in size of the plant area, omission of a rooflight bay and internal alterations.

Variation of Condition 1 of listed building consent dated 12 February 2020 (RN: 19/10031/LBC) for, 'Use of the basement as offices (Class B1), erection of single storey extension at rear third floor level, installation of air-conditioning units within vaults at lower ground floor level and extractor fan at roof level and associated works of internal and external alterations to 1 Chesterfield Street and 16A Curzon Street'; NAMELY, internal and external alterations including; infilling of vault openings; replacement of a door with a sash window to front area; introduction of maintenance access openings to the new link within the Chesterfield Street elevation; rationalisation of external services to improve roof drainage; introduction of service trenches to lightwell; removal of window horns; and introduction of ventilation grilles to the elevation at lower ground floor level.