Plantroom refurbishment at Old Bailey Central Criminal Court, London

This £37M refurbishment programme, started in 2014 and expected to take 10 years, was commissioned by the City of London Corporation to replace aging plant equipment at the Old Bailey Central Criminal Court.

With plantrooms dating back to post-war reconstruction in the 1950s, the replacement MEP systems offer improved energy performance, reduce building emissions and give greater control over the internal environment.

Project background

The Grade II listed building houses 18 courts and 52 prison cells over three floors. Since the 1960s, the HVAC system has been powered by four oil-powered steam boilers, which were proving increasingly difficult to maintain. The project was commissioned to replace the central building services plant: the boilers, chillers and air handling units (AHUs).

The Old Bailey handles 1,500 of the UK’s most serious criminal cases per year, with two sittings in each of the 18 courts per day. The work was split over 5 phases, over a period of 10 years, to enable the Court to keep operating with only one or two court rooms closed at any one time.

Restrictions on maintaining the existing features of the building and making use of existing spaces made the project more challenging, and therefore the new installation was designed to be installed across several spaces:

• Original sub-basement boiler room cleared out to house the new, gas-fired boilers.
• Two new heating mains run along ‘Dead Man’s Walk’ (original corridor to the gallows) connecting new boiler room to old boiler room.
• Disused oil pump room converted to the new pump room.
• East End plantroom housing the existing oil-fired steam boilers, operating until the new systems are fully operational.
• A sub-basement AHU plantroom for the new AHUs, replacing the old equipment.
• A 2nd AHU plantroom to house more of the new AHUs.
• A new chilled-water plantroom.
• Clearing of ‘the undercroft’ to house new heating mains.

Deliverables required

MultiCAD’s expert team provided

• Point cloud scanning
• MEP Coordination
• BIM Modelling

Point cloud (or 3D laser) scanning was used to get accurate models of the existing spaces and services. A fully coordinated MEP Revit model, using the latest BIM software, allowed easy integration and information sharing between all sub-contractors.

Main challenges

As the Old Bailey is a Grade II listed building, the MEP work had to retain and protect heritage features like the ironwork and brickwork of the original building.

An additional stipulation for the project was that it would not interrupt the proceedings of the 18 courts and that security of the building and cells would not be compromised. It was agreed that, of the 5 phases of the project, only 2 courts could be closed during phase 2 and only 1 court could be closed at any time during the later phases.

To avoid disrupting the open courts, it was agreed that noise would be limited while the courts were in session. These requirements created a need for detailed scheduling and workforce management.

Solutions provided

Interserve Engineering Services Ltd, appointed MultiCAD Solutions to carry out the production of a Building Information Model (BIM) and Co-ordinated M; E & Public Health construction drawings associated with the Plant Replacement works at the Central Criminal Court – Old Bailey. The Client for the project in question was the City of London and Interserve would like to confirm that MultiCAD Solutions performance was acknowledged by Interserve – and their client – as being exemplary.

Francis Capes, Operations Manager, Interserve Construction

During the initial consultation phases, MultiCAD carried out point cloud scanning, using a 3D laser device to create accurate models of the existing site and exposed MEP services. Designs for the new MEP services could then be created to fit existing spaces and to avoid clashes with original plant, pipework and electrical services that were to stay in place.

A complex MEP Revit Model was produced with full co-ordination to avoid clashes and ensure the proposed MEP services would fit in the existing site, integrate with existing services and avoid compromising historical features.

To avoid disruption to the courts the 1960s oil-fired boilers were kept in place to ensure a phased switch over of the heating and cooling systems. As the existing boiler room couldn’t be used, seven new gas boilers were installed in the building’s original and disused coal-fired boiler room. A mezzanine level was designed in this space to accommodate the seven units. The new gas boilers were selected to be more energy efficient and produce fewer emissions than their predecessors.

The designs for this project included one AHU per court, instead of the previous one AHU serving two courts, which required accurate design of enough plantroom space to accommodate the extra units, as well as the new ductwork required and its connection to the existing ductwork.

Having worked with MultiCAD for over 4 years at The Old Bailey, it has truly transformed the way we approach design and construction. From the initial consultation to project completion, their team demonstrated unparalleled expertise in BIM software, ensuring seamless integration across all stages of our project.

Their attention to detail, coupled with their proactive approach to problem-solving, helped us identify potential issues early, saving both time and costs. The team is responsive, reliable, and truly goes above and beyond to ensure customer satisfaction.

Thanks to their cutting-edge technology and collaborative mindset, we were able to make more informed decisions, optimise our workflows, and enhance overall project efficiency.

The results speak for themselves — precise models, better coordination, and a smoother construction process.

I highly recommend MultiCAD to anyone looking to take full advantage of BIM capabilities for smarter, more successful projects.

Kerim Copeland, Mechanical Engineer, Tilbury Douglas

Discuss your project with our experts

For MEP and BIM expertise that will improve coordination, prevent delays and save on costs contact us today.