Case Study // Horseferry Magistrates Court – Barratt West London

Phase 1

Horsferry Magistrates Court was opened in 1974 and was one of a series of three larger court houses within the London Region. Horseferry Magistrates served as the court where the Chief Magistrate of England and Wales sat with all extradition and terrorism related cases. Erith were employed by Barratt Homes London as Principal Contractor to carry out the top down demolition of a 8 storey reinforced concrete structure with Brick clad.

Phase 2

Horseferry Road Magistrates Court was redeveloped by Erith Contractors on behalf of Barratt West London. The basement scheme reuses the existing diaphragm wall and replaces the existing basement structure with a new deeper structure. Swanton Consulting was tasked to implement a methodical temporary works design proposal to aid the reconstruction of the basement box.

The original scheme relied on providing a new piled basement structure within the existing diaphragm wall, which was to be propped at three levels. We proposed an alternative scheme, using two levels of propping and a change of the basement structure to a raft slab. These proposals offered the scheme a significant reduction in terms of cost and time.

The propping was a mix of fabricated steelwork for the upper level, with substantial tubular props and wailings. For the lower level, we proposed using part of the permanent works wailing beam as temporary works and supporting this back to posts cast into the central raft slab with proprietary props. The use of proprietary props for the low level was driven by the short duration that they would be in place.

A major part of the work was in assessing the capacity of the existing diaphragm wall from investigation works and an assessment of the geotechnical capacity of the wall, compared with the loads imposed on it from the revised dig levels. We demonstrated to Westminster that the proposed scheme was sound through their Technical Approval scheme.

Project Goals

  • No reportable health, safety or environmental incidents or accident
  • 97.4% of all demolition arising’s recycled
  • Project completed within contract programme
  • Project completed within contract budget