Catching Up With 150 Leadenhall Street

6-8 Bishopsgate and 150 Leadenhall Street form part of a small collection of quality Miesian slabs in the City of London that could soon be demolished if plans to build a new skyscraper on the site get the go-ahead.

The existing buildings were developed as part of a masterplan by Gollins Melvin and Ward drawn up for a consortium of developers led by Barings Bank who ended up taking 6-8 Bishopsgate as their headquarters. 150 Leadenhall Street is considered such a high quality modernist building that it was even considered for historical protection earlier in 2015, although this was refused.

The scheme designed by Wilkinson Eyre consists of a part 8-storey, part 20-storey, part 40-storey skyscraper with an L-shaped footprint and 70,000 square metres of internal space that mirrors the footprint of the site, at least on lower levels with L shaped floors. South facing roof terraces are provided at the 9th level, and the 21st with a smaller one on the 30th. The top floor will not only have three meeting rooms, but also a viewing gallery for the exclusive use of the building's tenants. Despite this it is possible to have public access directly from the lobby to the viewing gallery.

The scheme has changed radically from its early concept in January 2014. The original pre-application concept featured a curvaceous tower that responded strongly to the Pinnacle which was to stand to its immediate north and followed the triangular profile of the Leadenhall Building to its east as to not interrupt the views of St Paul's Cathedral from Fleet Street. This plan was dropped after the planners of the City of London suggested that perhaps a curving building was less suitable for site than a rectangular one.

This sent the architects scurrying back to their drawing boards in April 2014 to come up with something rather more blocky although the increasing size of the floor-plates had made the building so fat it would have appeared beyond the profile of the Leadenhall Building when seen from Fleet Street so this in turn was dropped.

The final scheme is still stacked as with the previous version but with each block slightly rotated on the one under it hence the nick-name The Jenga Block. It continues to have cantilevered overhangs although is slim enough to adhere to the profile of the Leadenhall Building. The corner element which would stand where the former Tokio Marine building is set to be low-rise with stone cladding, whilst the tower itself will have glazing, and aluminium fins on the middle section. Topping the tower above the plant levels is a pavilion section, that perhaps resembles that of the Rothschild headquarters by Rem Koolhaas.

The scheme is being developed by the Mitsubushi Estate Company who hope that they will be able to complete the scheme as early as some time in 2018, although given they have to demolish an almost 90 metre tall tower on part of the site, this seems ambitious.