[2] Its eclectic style was designed to be a link between the ornate Gothic Revival Manchester Town Hall and the Classical architecture of the Central Library.

[1] The building, built by J. Gerrard & Sons Ltd of Swinton, is essentially Gothic in character, with ornately carved tracery and a steeply pitched roof interpreted in a contemporary style.

[4] The building is linked to Manchester Town Hall by two covered bridges at first-floor level over Lloyd Street and has an irregular plan with a concave south side facing the Central Library.

[4] Charles Reilly, a contemporary architecture critic, thought the extension was "dull" and "drab" while Nikolaus Pevsner considered it was Harris's "best job".

The public entrances on Mount Street and St Peter's Square were restored to their 1930s appearance and staircases to the lower ground floor were reinstated to access the Central Library which was extended into the basement.