Overview
Spence were commissioned to construct a control centre for London Ambulance Service (LAS) NHS, converting the existing office space on the 5th floor of Bernard Weatherill House in Croydon.
As a 24/7 call centre for the emergency services, the entire fifth floor required resilient mechanical, electrical and public health (MEP) services to enable it to continue functioning in the event of a power failure within the building.
Scope
The project was split into two main construction phases to accommodate the differing yet extensive scope of works.
5th Floor Refurbishment
The call centre required the provision of desk space for 205 people, along with new training rooms, new meeting and wellbeing rooms, an adapted comms room and a kitchen with a tea point and zip taps.
The existing comms room was adapted to meet the needs of the control centre, with new fire protection, electrical alterations and a gas suppression system. The condensers for fire dampers were located on the thirteenth floor, so pipes and cables were fitted to provide access.
Training rooms and meeting rooms with glass partitions were constructed. A sliding acoustic partition system was provided, allowing the client to separate the meeting room into two distinct rooms and seal them acoustically.
Each desk needed to be UPS backed and generator backed, but the office had no cable management system. The bulkhead was lowered by 200ml and independent Unistrut system was created to provide sufficient space and support for both the cabling and the AC system.
Chilled beams were installed to provide heating and cooling to the office. An independent VRF system was implemented to enable the client to control the circulation and temperature in different parts of the office, accommodating the large quantity of computers required without needing excess piping.
Since it was a 24hr call centre, aural fire alarms were impractical, so they were instead replaced with visual beacons. The Visual Alarm Devices (VADs) employed a colour-based system, with the colour of the flashing light changing depending on the severity of the incident, giving the control centre employees ample time to resolve any issues.
The office space was decorated with vinyl floor finishes, acoustic wall panelling, a double-glazed wall partitioning system and changing cubicles, lockers and an accessible WC for the staff. The client originally wanted to reuse the carpet, but upon seeing one elevation a new carpet was fitted instead.
Power Resilience Installation
The nature of the control centre meant that it required self-contained HVAC and electrical power systems to support the control centre in the event of a blackout. The existing building MEP services therefore had to be modified to incorporate shut off valves and dampers to allow for the independent fifth floor systems.
A used plant room was refurbished to store the electrical equipment, fuel tanks and generator. The solar panels were stripped out and replaced with electrical infrastructure to support the control centre activity, a battery room and a generator to provide emergency power to the fifth floor should the need arise.
A standby generator was procured, installed in the plant room, tested and commissioned. In order to support the whole of the fifth floor, the generator required 20kl fuel tanks which were placed in the basement and connected to the generator through pipework and riser routes.
Modifications were undertaken to the heating and cooling pipework to disconnect them from the central building services and enable them to be fed from an independent ASHP system. In order for level 5 to be independent from the rest of the building, heat pumps were installed outside.
The existing CCTV system in Bernard Weatherill House was removed from the fifth floor and new CCTV services linked to the LAS CCTV system were installed.
Challenges & Solutions
The client was poorly advised during the tender period, and as such the scope and programme differed massively from the original plans. Spence worked closely with the client to modify the programme so that the project could be achieved by a suitable and viable date, and to fulfil the project requirements alongside the client’s budget.
The original design had planned for the generator to be situated on the roof of the building; however, this did not account for the size of the generator required to support the power needs of the whole floor, and as such this was quickly found to be inviable. Since the consultants were removed, Spence picked up the design management and underwent five different design iterations, until finally a solution was found in a refurbished plant room which was craned onto the site. The plant room was located outside the main office area so that it could provide sufficient power whilst not educing the space needed for the control room employees.
The project took place within a live building, so works were done out of hours and in compliance with noise restrictions. The loading bay and goods lift were utilised for deliveries and waste away to prevent interference with the office staff.
The plant room was not part of the initial scope and was thus not part of the existing building. Due to its size it had to be craned in and erected over a weekend to avoid noise pollution to the working offices. The road was closed, and a traffic management plan was set up to prevent disruptions to the public.
