DL M&E Building Services Ltd was proud to deliver the complete Mechanical and Electrical scope for the major refurbishment of Bow Bells House, a prestigious property in the City of London directly opposite St Paul's Cathedral. Working alongside the project team, we transformed the building's services infrastructure with a strong emphasis on decarbonisation, energy efficiency, and the creation of high-quality end-of-journey facilities.
A cornerstone of the works was the installation of new Air Source Heat Pump (ASHP) units on the roof, replacing the existing chillers. These simultaneous heating and cooling units now provide the primary heating and cooling for the building, operating at 50/40°C LTHW and 6/12°C CHW. The system supports refurbished Air Handling Units (AHUs) and delivers significant efficiency gains. AHU001 and AHU002 underwent comprehensive refurbishment, including replacement of inlet louvres/dampers, removal of old frost/reheat coils (replaced with new LTHW coils), retained CHW coils with renewed pipework, new M5/F7 filters, thermal wheel replacement, fan bearings, inverters (Danfoss FC102), and drive sets. AHU003 and AHU004 received targeted internal cleaning, heating coil upgrades, fan bearing/drive belt replacements, and other defect rectifications. All works ensure compliance with current Part L requirements and contribute to the improved “B” EPC rating.
For the basement End-of-Journey facilities, we designed and installed a dedicated Mechanical Ventilation with Heat Recovery (MVHR) system utilising aluminium heat exchangers. This provides tempered supply air to male and female changing areas while extracting from WCs and showers, with heat recovery and undercut doors for pressure control. A standout technical achievement was the new Basement Smoke Extract System, installed to EN 1366 standards. Comprising two Flakt inline fans complete with attenuators, seven smoke dampers, fire-rated ductwork, and a control panel linked to the fire alarm and MVHR, this system ensures safe smoke management for the amenity spaces – a key innovation that enhances safety without disturbing the overall building layout.
Domestic water services were fully upgraded with boosted cold water (including double non-return valves, pulsed meters, and local isolations) and new direct-fed electric hot-water cylinders serving WCs, showers, locker rooms, basement cleaners’ sink, and Level 5 Business Suite. Above-ground drainage was routed within raised floors with air admittance valves, rodding eyes, and precise falls. All new and existing pipework was chlorinated and commissioned.
Electrically, we retained and modified the LV distribution, installing new split-load distribution boards (with separate power/lighting metering for Part L compliance and surge protection) and dedicated ASHP supplies via 150mm 4C SWA cables. New small power supported the End-of-Journey areas, while refreshed lighting schemes featured recessed downlighters, linear LEDs, trimless fittings in WCs and the business lounge, plus a new Simmtronic DALI system in reception. Fire alarm and PAVA systems were modified to deliver full Cat A coverage across tenanted floors, central cores, and new amenity spaces.
These works have delivered a modern, sustainable, and tenant-ready building while preserving existing infrastructure where practical. The project exemplifies DL M&E Building Services Ltd’s expertise in complex city-centre retrofits and low-carbon M&E solutions.
