Parc Prison, which opened in 1997, currently houses 1,670 Category B prisoners – but new plans for extending the prison would provide accommodation for an additional 345 inmates.
The prison currently has 676 staff, with an additional 100 staff planned to support the extra prisoners.
The expansion proposals would see a boundary wall demolished and repositioned, the construction of a K-shaped block added to the main building, along with a new gym and multifaith building.
A new access road would be built to the north of the prison, and a new car park to the east.

(Image: Galliford Try / Lichfields)
Galliford Try Construction Limited says it expects to submit full plans to Bridgend County Borough Council in July.
The Ministry of Justice (MoJ) owns the prison, which is operated by private security company G4S.
The prison has been the subject of a recent damning report criticising an “alarming” flow of drugs which led to “a spate of tragic deaths”. There were 17 inmate deaths at Parc Prison last year, more than any other UK prison.
