[1] The building was commissioned to replace the mid 19th-century Spring Gardens headquarters inherited from the Metropolitan Board of Works.

[8][9] The Island Block was built on what was then a roundabout (now a peninsula) between County Hall, St Thomas' Hospital and Waterloo Station.

It was notable to the passing public for three main reasons: it was of a completely different architectural character to any of the other nearby buildings, it had no entrances at ground level (though there were emergency exits), being accessible only by a bridge and a tunnel both from the SE County Hall building, and it had orange sunshades, designed to be lowered and raised together automatically when the sun shone, rather than by local control which would look less pleasing on the outside.

Disliked by many Londoners, it was nonetheless considered "distinguished" by its architect and some other experts, and noted as an early example of open-plan office interior, which should have been listed.

During the 1980s the then powerful Labour-controlled GLC led by Ken Livingstone was locked in conflict with the Conservative national government of Margaret Thatcher.

[12] On 21 October 2005, the High Court of England and Wales upheld a bid by the owners of the building, Shirayama Shokusan, to have the Saatchi Gallery evicted on grounds of violating its contract, particularly using space outside of the rented area for exhibits.