Excavation of basement level beneath footprint of existing house with walk on rooflights; Rebuilding of bathroom extension at lower ground floor; Erection of extension at ground floor level over octagonal wing and creation of new parapet; Erection of infill extension on northeast elevation; Remodelling of bay on southeast elevation at lower ground floor level; Erection of replacement dormer; Demolition of existing retaining walls on south east elevation and eastern lightwell and construction of new metal escape stairs in these location; Replacement of windows; Rationalisation of drainage, repair of stucco render, repair/ refurbishment and part replacement of existing roof, refurbishment/ replacement of existing chimney and pots; Installation of Plant Machinery; Erection of bin and bike store to front garden; and associated external alterations.

Amendments to planning permission dated 23rd January 2023 (RN: 22/05428/FULL) for two-storey extension including roof-level plant along the Bressenden Place façade to provide a new office entrance pavilion (Class E), the provision of Class E office / retail accommodation, remodelling of the crown of Portland House and creation of a setback rooftop extension to provide office amenity (Class E) and an outdoor terrace, reconfiguration of the second floor plant accommodation fronting Cardinal Place, relocation of the zephyr on Bressenden Place, provision of cycle parking, public realm and associated works including window replacement and the application of a new façade treatment, namely to amend the wording of Condition 3 (Code of Construction Practice) to enable early works to be carried out in accordance with the Appendix A dated 22/11/22 signed by the Environment Inspectorate and prior to the discharge of Condition 3.