The top floor of a Cambridge car park is due to be ‘urgently’ demolished after corrosion of the steel structure has raised safety concerns.

“Significant structural stability concerns” have been raised about the Cosin Court Car Park in Tennis Court Terrace, a two-storey car park used by Peterhouse College, part of the University of Cambridge.

The college asked Cambridge City Council for permission to demolish the top floor of the car park, stressing the issue was a “matter of urgency”.

The private car park was built in the 1970s and currently has 71 car parking spaces.

A visual structural appraisal report submitted to the city council explained that 50 years of water leaking into the building and onto the supporting steel frame structure had caused corrosion.

The report said the steel frame was “heavily corroded” in places, creating “significant structural stability concerns”.

The consultant said if there were a local failure in one column, there would be a “risk of a disproportionate collapse sequence”.

It said temporary propping had been put in place to support the columns.

The report said repairing the car park could cost the college around £1million to £1.4million, and that there would likely still need to be a “rolling scheme of maintenance” after these repairs.

A planning statement submitted to the city council said the upper car park level needed to be taken down “as a matter of urgency”.

It added that in the long term, the college hoped to redevelop the car park, but that this was unlikely to be possible for several years.

It also said the loss of car parking spaces would be managed by the college.

The city council recognised the concerns about the car park and has supported the plans to take down the top floor, after the college agreed to install additional charging points for electric vehicles.

The planning officer said: “The existing development is not structurally sound with multiple areas of the steel frame of the building structure which show severe signs of corrosion, and so the existing building poses a risk to safety of future users of the site. The demolition of the first-floor elements of the car park are therefore supported.”