Architects have been parachuted in to review rivals’ work on BAA schemes as employees with construction expertise continue to leave the embattled airport operator.

Capita Architecture, 3DReid, Grimshaw Architects and Stride Treglown are among the firms commissioned to review their peers’ work on BAA’s £6bn construction programme.

A string of internal design managers are understood to have left BAA since the completion of Heathrow Terminal 5, forcing it to hire architects to do the job.

One source said: “They’re unable to hire anybody to fill essential management roles, so they are hiring consultants at exorbitant prices to carry out the work.”

Many of the firms are on BAA’s design framework. As well as designing the masterplan for Stansted airport, Grimshaw is understood to be acting as design manager for the £1.5bn redesign of the Heathrow East terminal, which is being designed by Foster + Partners with Vidal Arquitectos.

They are hiring consultants at exorbitant prices to carry out the work

Source close to BAA

3DReid has been appointed to act as design manager on a number of Heathrow schemes. Nigel Ostime, an aviation director at the firm, said the appointment was standard practice.

He said: “BAA employs people they know and trust to act as an interface between architect and client. It’s a way of finding good people to do the job.”

The news came as it emerged that two commercial directors have left BAA in recent months. Matt Riley, described as former Heathrow managing director Tony Douglas’ right-hand man, departed earlier this year. His replacement, Alan Brown, left soon after, to be replaced by David Johnson.

A spokesperson for BAA said: “At this stage, BAA seeks to exploit fully the capabilities of its supply chain. Architects we’ve worked with are well placed to add to our design leadership resource.”