Wates Smartspace appointed AMD Environmental to complete a number of upgrades to Croydon Combined Courts over 9 months. In this time the AMD team successfully refurbished 12no outdated Air Handlings units and cleaned the entire buildings ductwork to improve air quality, replace in-efficient LTHW/CHW and domestic water circulating pumps, and completed a site wide upgrade to the Court’s Building Management System including energy saving measures across the building, along with replacing the existing buildings main LV panel and 62no distribution boards throughout the building for new.

The challenge of this project was that the works had to be completed in a live building when the original concept of the project was for the courts to close. So the AMD team were dedicated to re-engineering, sequencing and co-ordinating the works to enable the courts daily proceedings to continue unaffected. This was particularly crucial in the aftermath of the Covid-19 Pandemic where courts have been working to reduce backlogs.

Works consisted of:

• Clean Ductwork in compliance with the TR19 and BS EN15780 for the existing VAV and mechanical AHU supply and extract ventilation systems.
• Conduct air quality sampling, prior and post main project works, in accordance to BESA Supply and install a new temporary bespoke Air Handling Unit across 3no different plant rooms in accordance with programme of works, (in 1no plantroom at any one time) to facilitate the refurbishment of the existing AHU’s and to maintain a ventilation service to the building at all times.
• In conjunction with above, disassemble new temporary AHU 3no times, in accordance with programme of works (in one plantroom at any one time) to facilitate the refurbishment of the existing AHU’s.
• Installation of VCD’s to existing ductwork over 3no floors to enable commissioning and final air balancing.
• Strip out, remove to ground level 5 No. existing roof mounted toilet & general extract fans and replace with 5no new.
• Strip out, remove from site 1No. existing roof mounted kitchen extract fans and replace with new fan.
• Strip out and remove from site 4No. existing HWS Circulating pumps and replace on a like for like duty basis with new.
• Strip out and remove the 9no existing belt driven pumping systems and replace with 9no new inverter drive pumps, with a selected revised duty.
• Supply, install and commission 6No. new supply and extract heat recovery run around coils to existing VAV and mechanical air handling units.
• Upgrade the BMS to suit the new requirements of the installation, including all new panels, pressure sensors, VAV dampers and control wiring within new trunking, whilst maintain control over plant and systems at all times.
• Upgrade the existing 53no on-floor heater battery boxes with new motorised dampers and controls to viable Variable Air Volume Control.
• Commission and set to work, all the above items.
• Replace 53no heater battery valves and actuators.
• Replace and upgrade 5no roof general and toilet extract fans.
• Replace and upgrade 1no roof kitchen extract fan.
• Install new Kitchen MCC panel complete with new inverters and BMS controls to IQ-4 which function and control the supply and extract fan/AHU.
• Fully flush and clean the existing LTHW & CHW systems, without disruption to plant.
• Chlorinate the domestic cold water service pipework to run-around-pumps sets.
• Installation of 2 no. new side stream filtration sets to LTHW & CHW systems (1 per system).
• Installation of new LV panel including new sub main cables from HV transformer
• Installation of 62no distribution boards throughout the building.
• Fully test and certificate electrical systems within scope.

Methodology

One of the most challenging tasks was to maintain the courts temperature and ventilation whilst carrying out full refurbishment of its main source – the Air Handling Units.

Each AHU was changed over a separate week on a continual rolling programme with use of a modular bespoke manufactured temporary AHU mounted on a skid. AMD achieved this with further careful planning at the early stages of the project under enabling works and this consisted of adding new line-sized LTHW & CHW flow and return valves in for system flushing, but also for inevitable connections to the temporary AHU. This meant it could be built and set to work when required and then dismantled, then wheeled to its next location for use week after week. Following this plan meticulously, ensured ventilation and temperature control to the courts was maintained during every shutdown.

The circulating pumps were replaced in a similarly carefully planned manner in order to avoid system downtime.

AMD first had to freeze both LTHW & Chilled pipework to enable new functional isolation valves to be installed in replacement of old isolated and removed the first pump, installed each new pump and set this to work. The second pump was then isolated, removed, and replaced.

Likewise, the BMS panel refurbishments were undertaken Out of Normal Working Hours to ensure the Courts could operate normally through summer and winter. Similar careful planning was followed when migration of new control and power cabling was brought in and removal of old control and power cabling, which was all removed. This required the new BMS panel to be built directly in front of the old and temporary trunking was used to facilitate this, whilst maintaining H&S procedures on site for all operatives.

Side-stream filtration was installed during the works to improve the water quality in the existing heating and chilled water systems, along with suitable flushing and dosing operations.

The existing main LV panel was first validated and then a ‘Black Building Test’ carried out to prove the operation of the associated generator. This test was carried out in conjunction with Wates and the courts FM provider ensuring all critical services were correctly isolated and re-energized for these works.

The new LV panel was installed within existing LV room and new submain cables installed, in conjunction with Wates and the FM provider the building was isolated by UKPN and the new LV panel connected to the HV transformer whilst also maintaining the supply to the existing. Over 4 weeks the existing sub main cables were migrated from the old LV panel to the new, this was all completed outside of normal hours with isolation notices raised to ensure all stakeholders were aware which areas were to be isolated and when.

Upon completion of migration the supply to the building was isolated by UKPN and the existing LV panel disconnected from the supply and stripped out.

The distribution boards throughout the building were replaced outside of normal hours on weekends. AMD & Wates produced an isolation schedule and request system to ensure all stakeholders were aware of the works to take place. On a Friday the existing DBs would be isolated and removed. On the Saturday and Sunday new DBs were installed, all circuits connected and then fully tested and certified.

All individual systems were commissioned immediately following the weekend work and again as a whole system at the end of the project.

Our project management team consisted of electrical & mechanical Project Managers and site managers, working alongside Wates site management team and Mace’s technical team.  Progress reports and weekly site meetings were used to co-ordinate work with the client and ourselves.

A programme of work was agreed before works started and developed during the works to ensure all elements were captured and carried out in a timely manner ensuring the users of the building were subjected to minimal disruption.

Health & Safety risk assessments and method statements were issued and reviewed with Wates at least 2 weeks before each element of works started, with dynamic reviews on the day if needed and Daily Briefings to ensure all site personnel understood the plan.  The overall RAMS were reviewed every 3 months or sooner to ensure they stayed current and reflective of the works on site.

Trade Quality Plans were created for both electrical and mechanical works, reviewed and agreed with the Wates project team.  The AMD processes were tailored to include the use of Fieldview which formed part of AMD and Wates Quality process, especially for QA inspection reports, permits to work, snagging and the Daily Briefings.

The AMD commercial dept worked alongside Wates, with both project QS’s ensuring cost management and change control were aligned and reported accurately.

These processes helped to ensure that a large project with high potential to disrupt the client’s critical operations was completed and set to work safely, on programme and to the client’s satisfaction.

The management and documentation process is the same for all of our projects, with just the site and project specifics being tailored individually for each.

Mace (client representatives) project management and technical team described the installation and execution of this project as the benchmark and model of how all HMCTS projects should be delivered.