“Aedas accused of failings over inadequate ventilation and overheating at six Exeter schools

Contractor Carillion has launched a £1 million court case against Aedas claiming that the architect failed to properly design six school projects in Exeter.

Aedas is accused of failing to properly manage a design process which led to windows being installed which provided inadequate ventilation and led to school buildings overheating.

Carillion says it was forced to carry out remedial work which in some cases involved installing new windows and skylights.

The contractor is seeking £893,479 plus interest and court costs for breach of contract and duty in relation to the design of windows by Aedas and its mechanical and engineering consultant Hoare Lee and Partners.

Papers filed at London’s High Court allege that Aedas failed to “exercise the reasonable skill care and diligence to be expected of a reasonably competent architect” and “failed to direct the design process adequately”.

The six schools were built between 2005 and 2008 as part of a PFI agreement between Devon County Council and Modern Schools Exeter, which in turn appointed Carillion.

Carillion’s case is based on a claim that Aedas and Hoare Lee decided to design windows which complied with a building regulations requirement that windows open to an area equivalent to 1/20th of a building’s floor area.

The contractor alleges that this decision was flawed and failed to take into account the fact that not all windows were able to be opened and some were to be fitted with restrictors which limited their openable area.

“No reasonably competent architect, lead designer, lead consultant or mechanical and electrical engineer should have disregarded the ventilation rates and/or overheating requirements and base the design solely on attempting to achieve compliance with the 1/20th requirement,” the contractor says.

A thermal study carried out by Hoare Lee concluded that the buildings would not exceed a temperature of 28C for more than 80 hours a year. But Carillion claims this study was based on the same incorrect assumptions.

“It subsequently became clear that there was a disparity between the thermal modelling carried out by Hoare Lea and the actual construction at the schools,” the contractor says.

A spokeswoman for Aedas said: “Whilst we consider the case against Aedas to be unfounded, regrettably Carillion have decided to pursue this claim. Unfortunately we are unable to comment further due to the impending legal proceedings.”

The schools are: Bradley Rowe Primary School; Priory High School; St James’ High School, St Peter’s Church of England High School; West Exe Technology College; St Luke’s Church of England High School.”