So while the extension has long since gone and now the Winter Gardens stand proudly next to the Town Hall can you still remember what it used to look like?
We have dug out some pictures from our archive to show you just what it used to look like and the last pictures taken before it became rubble and dust.
Want more Sheffield retro? Sheffield in the 1970s, Sheffield in the 1980s, Construction of the Millennium Gallery

1. Egg box extension
In 1977, a new council building in a modern style was added to the east of the Peace Gardens | JPIMedia Photo: Sheffield Newspapers

2. Unpopular building
The building was immediately unpopular and was nicknamed The Egg-Box after its appearance | JPIMedia Photo: Sheffield Newspapers

3. Arial view
The new building, complete with roof-garden, cost in the region of £9 million | JPIMedia Photo: Nancy Fielder

4. Cranes move in
The Town hall extension was built with a life-span of about 500 years but only lasted 25 | JPIMedia Photo: staff