20 St James’s Street, SW1A 1ES

Client : Grafton Associates
Programme : 34 weeks
Value : £3.5m


20 St James's Street

OVERVIEW

20 St James’s Street located in Mayfair, consisted of an 8 storey office block with retail units on the ground floor and basement.
The J.J. Fox cigar shop which was located on the ground floor was to remain live throughout.

CHALLENGES

Removal of roof, associated plant and cut and carve
of existing stair and lift cores from level 8 to basement. Removal of screed to all remaining floors.
Weatherproofing and structural support to J J Fox the ground floor humidor and the installation of site welfare to a steel gantry above Ryder Street.

Design and installation of loading gantry on St James’s Street and temporary works to retain the stability of the structure.

Installation of 5no. conveyor belts for the removal of demolition arisings from basement to level one loading gantry and of K Guard edge protection to all remaining slab edges.
Design and installation of 18no. 450mm diameter piles to a depth of 28m for the new lift and stair cores.

Stitch drill and probe to a depth of 3m in all pile locations. Obstructions were found up to depths of 6m. Basement excavation to a depth of 3m.

Suspension of the structure approximately 6m in the air, whilst the remaining floors were demolished, followed by piling and reduce dig.

ACHIEVEMENTS

John F Hunt were given the Considerate Constructors Gold Award.

Overcoming the obstruction removal and probing to allow for the piling to be undertaken.

Innovative engineering using balance beams and ground anchors to enable the support to the main party wall whilst still undertaking demolition.