Exacting Standards in Revitalised Office Block

The redevelopment of this 1960s office building overlooking Charterhouse Square offers over 38,000 sq ft of Category A open-plan office accommodation alongside 5,000 sq ft of retail space, located adjacent to the Farringdon East Crossrail station.

Bathgate Flooring’s Air Seal medium-grade steel encapsulated panel was utilised across all six floors to create an underfloor air plenum capable of distributing conditioned air with minimal leakage. Working with installer S J Durman Flooring, the system was configured for a CAT A fit-out to support air distribution from Denco units installed on each floor.

Products & Air Seal Gasket Solution

Manufactured at our UK facility in Hereford under the Permaflor brand, the panels feature a steel encapsulated construction with galvanised steel top and bottom surfaces, conforming to the PSA MOB PF2 PS/SPU Medium Grade British Standard. The panels utilise an innovative air seal gasket system, constructed with Class O closed-cell neoprene seals, enabling pressurised air to be delivered with near-zero air loss.

To adhere to PSA specifications, oversized panels were used along perimeters where perimeter cuts were smaller than 300mm. The complete assembly was installed on H-range PSA-rated pedestals adhered directly to the concrete subfloor.

Independent Performance Testing

Following completion, independent testing was conducted by Building Testing Limited (BTL) in December 2017 to evaluate air leakage across the plenum. The results confirmed that airflow through both the underfloor void and floor surface comfortably met BSRIA Guide limits and strict project specifications:

  • Plenum Void Operating Pressure: 12Pa
  • Target Volume Flow Rates: 1.80 m³/s (Level 6, Zone 1 South) and 0.82 m³/s (Level 6, Zone 2 North)
  • Air Flow Compliance: Level 5 testing demonstrated void air flow of 0.29 L/s.m² and total void + floor leakage of 0.70 L/s.m² at 50Pa, fully complying with target standards.

Project Highlights

Location: Charterhouse Square, Farringdon, London
Panel Used: BGM600 + Air Seal
Architect: Buckley Gray Yeoman
Owner: Helical PLC
System Size: 3,995 sq. m.
Completion: February 2018

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