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Case Studies – Lessons and Pitfalls
“The Services have failed, again. Whose fault is it?”
David Arnold,
Troup Bywaters & Anders, Reading, United [email protected]
RAE Visiting Professor, London South Bank [email protected]
Simmons & Simmons and SWEP Seminar - Tuesday 22 November 2016Heat Networks –Opportunities and Pitfalls
The Services have failed, again. Whose fault is it?
Effect, Cause, Solution, Cost and Liability
Typical Cases
Case Study – Major Hospital
Lessons Learned
Lloyds Building London
Effect:
Water found dripping
from S/S cladding
Cladding was lifted to
Investigate……
Lloyds Building London
Lloyds Building London
• Cause – Cladding joints not watertight
Lloyds Building London
• Cost – As reported by BBC News
• The celebrated British architect, Lord Rogers, paid a heavy price for his iconic 1980s creation, the Lloyd's of London building.
• Lord Rogers - together with engineers (Arup) and builders - paid £12m to cover the cost of repairs to the towering glass and steel landmark.
• Initially applauded for its radical "inside-out" design - service pipes and other usually hidden features were clamped to the outside of the building - it was later struck by corrosion. Remedial work took 18 months to complete.
Green Building Bristol
• Bank wanted a new prestige low energy
– “Green Office Building”
• Architect wanted a “clean uncluttered ceiling”
• Engineer wanted to use low energy chilled beams
Green Building Bristol
• Effect:
– Contractor could not commission the system
– Not enough cooling available
Green Building Bristol
• Causes:
– Novel technique – chilled beam above ceiling
– Contractor had changed glass to save money!
Green Building Bristol
• Cost:
– Replacement glazing on three faces
– Additional AC as chilled beams inadequate
• Liability: contractor
Verizon Office Complex
• Office Complex of six interlinked buildings
• Built in two phases, Phase 1
– Three 3-storey office blocks
– Basement car park and energy centre
• Phase 2
– Three 4-storey office blocks
Effects
• Control valves failing after a few weeks
• Main chillers failed after 12 and 18 months
• Contractor investigated – did remedial works
• Remedial works failed to solve problems
Effects
Causes
Costs
• Replacement of four chillers
• Replacement of boilers
• Additional expansion vessels
• Complete replacement of heating and chilled water pipework on office floors
• Additional water treatment/cleaning
• Disruption to business
District General HospitalPVC Pipe Failures
• Major Hospital Development – Scotland, 500 beds
• PFI Contract had clause re Structural Defects – 10 years
• Heat networks serving several hot water generators
• Scottish water aggressive to copper
• Pipes had to be either stainless or C-PVC
District General HospitalPVC Pipe Failures
• PFI Contract had clause re Structural Defects – 10 years
• Structural Defect defined as:– (A) an inherent defect in the structural works of the New Build
Hospital…
– (B) the use of any Prohibited Materials…..
– (C) any other inherent defect in the Facilities,
District General HospitalPVC Pipe Failures
• Trust expert argued serious H&S risk of pipe failures in ceiling voids during maintenance or modifications
• Polymer expert said pipe prudent to replace pipes after initial tests.
• A few incidents occurred causing some small bore pipes to fail.
• Trust expert said hot water pipework has become so brittle - serious risk to the operation of the hospital and replacement necessary.
• Trust expert said this was a “Structural Defect” i.e. Contractor liable
District General HospitalPVC Pipe Failures
District General HospitalPVC Pipe Failures
• Polymer expert pipe samples failed under a single impact: greater than allowed in BS EN 744:1996.
• Polymer expert said pipe failed to meet the manufacturers predictions of 50 years
• Polymer expert said cause was phthalate esters from fire collars.
• Trial date set for September 2015 – Polymer expert introduced new theory
• Trial date reset for July 2016
District General HospitalPVC Pipe Failures
• Effect - some defective fittings installed originally that led to calling in expert;
• Cause – Mechanical properties of plastic pipe changes over time;
• Plastic pipe is less robust than metal
• Cost – Nil for remedial works – several £M for costs
• Liability – case dropped
Lessons
• Design:
– Avoid over complicated designs
– Avoid innovative techniques without thorough testing
• Forensic analyses:
– Don’t speculate causes
– Don’t get hung up on initial theories
– Review design processes from beginning
– Analyse each stage of design process
