£35m is being spent on expanding Parc Prison in Bridgend.
The jail's capacity will be increased by 387 prisoner places, to reach 1,723.
A new houseblock will be built, as well an industrial workshop, education building, visitor centre and gatehouse. The work will also include a 350-space car park, extended perimeter walls and security fencing.
G4S, which runs the prison for the Ministry of Justice, says 78 new jobs are expected to be created, including 43 prison custody officer positions.
Preparatory construction work has already started, and the work is expected to be completed ready for extra prisoners to arrive by December 2014.
Yesterday, the chosen location for a new 2,000-inmate super prison was announced as the former Firestone factory site in Wrexham.
Wayne Ridgely, Shaun Beasley's brother-in-law, spoke after the inquest at Aberdare Coroner's Court. He said that, had the changes to the way prisoners are cared for been implemented before Mr Beasley's death, 'he would still be here today.'
G4S, the security company which manages Parc Prison on behalf of the Ministry of Justice, says that there's been a 'fundamental review' of the way vulnerable prisoners are cared for since Shaun Beasley's death.
The company running healthcare at HMP Parc at the time of Shaun Beasley's death, Primecare - Forensic Medical Services, says it recognises the care provided 'fell below our high standards.' It sends its 'sincerest condolences' to Mr Beasley's family and friends.
Shaun Beasley's family say the inquest's verdict confirms their judgement that he had been 'let down'. In a statement, they said 'he was highly vulnerable and suffered from serious mental ill health. He had a history of self-harm and had made several serious suicide attempts.'
They say, on the night of his death, Mr Beasley phoned to say he could not cope. His sister immediately called the prison to tell them of his state of mind. He was already on half-hour observations, but that was not increased and he was found hanging in his cell shortly after midnight.
A man who was found hanged in his cell at Parc Prison, near Bridgend, in August 2010 took his own life "in circumstances contributed to by neglect", an inquest jury has ruled today.
The inquest at Aberdare Coroner's Court heard how Shaun Beasley, who was 29, was known to have a history of self-harm, paranoia and depression, and was placed on a healthcare wing of the prison where he could be checked every half an hour.
30-year-old Gavin Williams had spent 15 years in and out of custody, culminating in being incarcerated at HMP Parc in July 2010.
Despite his claims to never having picked up a paintbrush before his time in jail, the Invisible Walls project helped him nurture a talent for art.
His murals became a distinctive feature on the walls of the prison, and after his release, Gavin started his own painting business.
"My eyes have now been opened to the damage coming to places like that do to families" he says.
"Having that guilt has made me more determined to be more successful in my life and not to go back to the same place".