Kier has completed the construction of HMP Millsike for the Ministry of Justice, increasing prison capacity by approximately 1,500 and marking a significant milestone in the UK’s prison infrastructure.

The facility was officially opened by Lord Chancellor and Secretary of State for Justice, Rt. Hon Shabana Mahmood MP, alongside Minister of State for Prisons, Probation, and Reducing Reoffending, Lord Timpson OBE.

HMP Millsike is a Category C prison and the UK's first all-electric correctional facility. It is also the first prison developed under The Alliance 4 New Prisons (A4NP), a collaboration supporting the Ministry of Justice’s broader plan to deliver 20,000 new prison places. A4NP is responsible for 6,000 of these, using an innovative delivery model that promotes repeatability and continuous improvement.

As an all-electric facility, HMP Millsike operates on renewable energy, generating more than 8,500kWh to power its systems. Advanced solar panels, heat pump technology, and energy-efficient lighting allow the prison to use only a quarter of the energy typically required to heat traditional Victorian-era prisons.


Kier's construction of HMP Millsike has left a lasting legacy in the local community. Through its Making Ground programme, the project trained, upskilled, and reskilled 40 prison leavers. Employment opportunities were provided for 29 prison leavers and 44 prisoners released on temporary licence (ROTL). Additionally, 85% of prisoners who worked on the project secured employment six weeks post-release.

Beyond rehabilitation efforts, the project created nearly 800 jobs for local residents within 50 miles of the site and supported 92 apprentices and trainees. Kier also invested significantly in the local economy, with 45% of project spending directed within a 50-mile radius.

Educational outreach was a key initiative, with the project team engaging over 1,300 local school children to inspire careers in construction through apprenticeships and further education opportunities.

Kier's Strategic Projects team, in collaboration with in-house mechanical, electrical, and plumbing (MEP) experts, successfully managed the complex MEP installations at HMP Millsike. The project leveraged cutting-edge digital construction techniques, including OpenBIM and digital standardisation, ensuring a highly efficient and precise build process.

A 3D digital twin was developed using Ynomia’s platform, allowing real-time tracking of every component's performance throughout the construction process. This digital innovation resulted in significant time and cost savings, enhancing project efficiency and long-term operational effectiveness.

With the completion of HMP Millsike, Kier has once again demonstrated its leadership in delivering high-quality, secure, and sustainable justice sector infrastructure, setting a new standard for the future of UK prisons.