Designed by architect Rafael Viñoly and costing over £200 million, 20 Fenchurch Street features a highly distinctive top-heavy form which appears to burst upward and outward.

The Secretary of State for Communities and Local Government, Ruth Kelly, called in the project for another public inquiry[7] which, in 2007, ruled in the developers' favour and the building was granted full planning permission.

[15] The 'sky garden' at the top of the building was claimed by the developer to be London's highest public park, but since opening there have been debates about whether it can be described as a 'park', and whether it is truly 'public' given the access restrictions.

[16] The garden spans the top three floors, which are accessible by two express lifts and include a large viewing area, terrace, bar and two restaurants.

Cementitious spray was applied to the steelwork, which was supplied directly to the entire building using a purpose-built mixing and pumping station located on the ground floor.

"[10] Earlier in 2013, during a public inquiry, Paul Finch of the Design Council CABE said he regretted supporting the project, saying that the developers "made a mess of it" and were architects of their own misfortune.

[27][35][36] In September 2013, the developers stated that the City of London Corporation had approved plans to erect temporary screening on the streets to prevent similar incidents, and that they were also "evaluating longer-term solutions to ensure the issue cannot recur in future".

[40] In an interview with The Guardian, Viñoly said that horizontal louvre windows on the south side that had been intended to prevent this problem were removed at some point during the planning process.

[41] The Sky Garden, which was described as a large, free, public viewing space at the top of the building, was part of the justification for the planners allowing such a vast office block to be built on the edge of a conservation area.

Computer visualisations shown to the planners included a glade of full-height trees, but the garden as constructed has a slope with ferns and succulents instead.

[42] Free access to the public is provided in 60-minute slots, until 18:00 on weekdays or 21:00 on weekends & Bank Holidays, after which the garden is available only to paying customers of the catering facilities.

Oliver Wainwright, architecture critic of The Guardian, described it as "a meagre pair of rockeries, in a space designed with all the finesse of a departure lounge".

[10] The City of London Corporation's former chief planner, Peter Rees, who approved the structure, said: "I think calling it a sky garden is perhaps misleading.

"[43] In July 2015 it was reported that planners are to consider a landscape architect's alterations to the layout, following claims it is not consistent with illustrations submitted with the original planning application.

"[46] In June 2012 the insurer Markel Corporation signed a tenancy agreement with the developers to move into 20 Fenchurch Street upon its completion.