Please refer to our Privacy policy for important information on the use of cookies. By continuing to use this website, you agree to this.

Building a training prison for young adult males


Building a training prison for young adult males

Building a training prison for young adult males

Working under the Ministry of Justice (MoJ) Strategic Alliance Framework, the HMP/YOI Isis development comprises a 480-place Category C training prison for young adult males.

The building was constructed on the site of underused land within the existing Category A HMP Belmarsh prison perimeter wall.

The accommodation consists of:

  • Two three-storey houseblocks, with galleried spurs and central galleried atrium hub, incorporating an induction facility

  • Entry Building: incorporating staff lockers, a visitor reception area, gate lodge, visits areas, videocourts and stores

  • Central building comprising an educational ‘academy’ of workshops, classroom and library facilities

  • Secure external works including all weather sports pitches, exercise yards with equipment, hard landscaped courtyards, planted areas and a secure covered walkway ‘street’

  • External works outside of the secure perimeter comprising road access, pedestrian and cycle access, visitor car park, vehicle security barriers, staff parking, bicycle parking, hard landscaped and planted areas, including wetland.

Design, planning and construction of the prison

Interserve worked with the MoJ, its professional team and the end users to challenge and develop the brief, produce design alternatives and support the planning process, including full planning consent.

Our collaborative team developed the budget model, which was taken through the Treasury approval process, and converted the brief into a detailed project proposal. We market tested the proposal and had ownership of project design and construction. The client’s critical success factors for the project were meeting the Treasury approved budget within the annual constraints and completing the new build prison in the first half of 2010.

A lean approach to construction helped to achieve the demanding 77 week programme. Activities were broken down to allow day-to-day management and control. Individual task durations were no more than ten days which provided more detail and allowed greater clarity of the tasks that need to be completed.

By involving our supply chain in putting the Plan together and holding collaborative lean workshops, Interserve ensured ‘buy in’ while using our supply chain’s specialist knowledge. A buffer was included in the programme of approximately 15 percent of the overall duration of the project.

On a weekly basis actual progress was monitored, the programme was re-scheduled, and the following key project performance indicators produced:

  • A tracked and buffered programme

  • The percentage of tasks started

  • A critical path

  • A four-week plan

  • A two-week plan

  • A buffer chart

  • The percentage of tasks completed

This approach to monitoring project performance ensured problems were brought to the surface early so that time is not wasted later in the process. These tools were used in the management of the supply chain through weekly meetings and management of the operatives through visual displays, clearly demonstrating critical operations and sequences.

The use of lean construction techniques further enhanced collaborative team work to develop efficient and effective solutions that challenged existing processes. With participation from the client team and the Interserve supply chain, we found smarter and quicker ways of building safely to meet a challenging programme.

BREEAM Excellent rating

At HMP / YOI Isis, a BREEAM (Building Research Establishment Environmental Assessment Method) rating of Excellent was targeted and achieved, a first for a public sector newbuild prison.

The process for targeting and evaluating the relative value for money benefits for each of the BREEAM credits was undertaken from the preliminary pre-planning application stage and was continuously monitored to ensure the rating was met, while evaluating the cost of each credit relative to the input it gave to the overall BREEAM score.

Lessons learned

From day one, we co-located the construction team from Interserve and the designated operational team from the MoJ who were to manage the prison once completed – creating total collaborative working and successful, issue resolution without delay.

We worked closely with the MOJ technical team during early design stages to review compliance with NOMS standards. This allowed for detailed security requirements to be integrated in to the design coordination process, ensuring a more informed design from the start.

We ensured a Derogation Change Schedule was produced and actioned from the commencement of the project. This provided confidence that all information was clear for all members of the project team throughout the build process. When the flow of changes appeared to increase towards the end of the construction process, we worked together with the MoJ teams to agree to undertake a series of additional works post-handover, to avoid any delay to completion.

We formed and undertook a clear handover process, with full involvement of client and end user, including all documentation, training and demonstrations, and a pre-handover meeting process to track and manage progress of the handover. In addition to this, we assisted the MoJ commissioning team in moving the prison from completed to operational, providing additional commissioning staff to assist with the building of furniture, fixing signage etc.

A lean approach to construction helped to meet the demanding 77-week programme.


Ministry of Justice 


United Kingdom


£115 million

Want to know more? send us a note here and we'll be in touch

Interserve is committed to protecting and safeguarding your personal data. Please visit our Privacy Policy to find out how your data is used.

*denotes mandatory field

There was an error submitting the form. Please try again.

Thank you. Your message will be with us shortly.
If you wish to write us another message please go back.
We will be in touch soon.


We work with high profile government and private sector clients, delivering everything from minor property services roll-outs to large complex construction projects.

Latest Insight


What are the benefits of building to Passivhaus standard?

#Passivhaus built Richmond Hill Primary School in Leeds uses 80% less energy than normal build schools #construction #ingenuityatwork
Publication 2017 half-year report Download