It is formally recognised as one of the National Amenity Societies,[1] and as such is a statutory consultee on alterations to listed buildings within its period of interest.

The catalyst to form the society was the proposal to replace Lloyd's of London's Classical-style 1920s headquarters with a new modernist Richard Rogers building.

Marcus Binney (founder of Save Britain's Heritage), John Harris (director of the RIBA drawings collection) and Simon Jenkins (editor of London's Evening Standard) felt that the existing building "represented a whole body of important architecture of the period that deserved more sympathetic assessment".

[6][11] They also considered Douglas Fairbanks and David Niven but "there was some concern that the stars of the Twenties and Thirties might not be around long enough to warrant putting their names on the letterhead.

Of the report, Bronwen Edwards, a C20 caseworker, said, "What is indisputable is these buildings are a unique record of social, economic and architectural history – a vivid reminder of the way people lived, worked and played through the century.