Pre-Construct Archaeology London was involved from the project design and initiation stage of the Westminster Ceremonial Streetscape Project (WCSP), of which archaeological investigations were a component part. This wide-ranging scheme saw the installation of a pedestrian and traffic management system, intended to improve security at street level across the core of the City of Westminster,  In 2017 PCA London was commissioned by WSP / Parsons Brinckerhoff to prepare a scheme-wide desk-based impact assessment and then undertake archaeological monitoring during test-pit surveys over wide project area, comprising 19 locations, mostly all of which were within Tier 1 or Tier 2 Archaeological Priority Areas. This project followed on from the earlier Whitehall Streetscape Project on which PCA also undertook fieldwork for between 2007 -2010.

An initial watching brief on trial holes in the public carriageway on Horse Guards Avenue, known as Location T of the WCSP exposed archaeological deposits and remains of masonry structures thought to date from the 15th century onwards, which were either recorded and excavated or preserved in situ.

As a result of the Location T watching brief, PCA was commissioned by FM Conway Ltd to conduct a series of small excavations required the re-excavation under archaeological control of the previously excavated trial holes, and then the archaeological recording of the remains present and the removal of those which conflicted with the proposed new foundations.

The excavations revealed the foundation elements of the Court Gate of Whitehall Palace, in existence in the 15th century but remodelled through the early 16th century by Cardinal Wolsey to serve York Place.

The archaeological fieldwork was successfully completed to the satisfaction of the Greater London Archaeology Advisory Service (GLAAS), at Historic England, planning advisors to the City of Westminster, and was followed by the delivery of a post-excavation assessment report and publication in The London Archaeologist Vol. 17 No.2/ Autumn 2023.