MAGDALEN College’s plan to extend its historic library is set to be approved despite concerns it would “obliterate” part of the building’s heritage.

The Grade II listed library, which was home to Magdalen College School until 1928, was built between 1849 and 1851 by John Chessell Buckler.

It was later adapted by Sir Giles Gilbert Scott, the celebrated architect who created Oxford’s Martyrs’ Memorial.

The college has now applied to build an L-shaped extension that will sit in a sunken landscape garden.

The application will go before Oxford City Council this month, and is recommended for approval by planning officers.

However, in a formal objection, the Victorian Group of the Oxfordshire Architectural and Historical Society said the revamp would “obliterate an important phase in the building’s history by removing all of the interventions designed by Scott”.

The group said the extension would also cause “irreplaceable damage to the historic fabric of the Buckler building”.

In its objection, the Victorian Society said “the proposed library extension would destroy the vertical character of the building” and would “destroy” the work of both Scott and Buckler.

English Heritage said it accepts the need to improve access to the building but said “the justification submitted for the extension to the basement of the Grade II* Buckler building is weak and there is no evidence to substantiate the expressed need”.

The council officer’s report into the application states that all comments and objections have been “given careful consideration” but “the council takes the view that the comments made, either individually or cumulatively, do not constitute sustainable reasons for refusing the application”.

The report states: “The proposal forms an appropriate visual relationship with the existing listed building and the surrounding development which lies within the central city and university conservation area and would appear sympathetic and in keeping with the street scene”.

In its application, the college said railings and parts of a boundary wall that were removed during the Second World War will be reinstated to “reanimate this important corner of Oxford’s cityscape”.

Parts of the Longwall Street wall that are in a poor state of repair will also be restored.

City councillors will decide on the proposals on Wednesday, May 30.