Plans emerged for a joint competition service run by RIBA, ICE and the Institution of Structural Engineers (IStructE) last week (news last week).
A lack of attention to cost means that the design solutions are often unbuildable, claim designers.
"The main problem with RIBA getting involved with bridge competitions is their traditional flagrant disregard for cost constraints which is critical to bridge design,” said Techniker director and architect Matthew Wells.
"One can do anything given the money but that is not what engineering is about. I really wouldn’t put bridge procurement in their hands at all."
Ramboll Whitbybird chairman Mark Whitby agreed.
"I wouldn’t advise clients to go through the RIBA route," said Whitby.
"It’s not something they can control. Many competitions fail because the solutions they choose don’t get built because they can’t be made to work. What would be required to make them work is uneconomic."
He remarked on the successes of other bridge design competitions that are run by bodies like local councils and are successful because they contact someone with bridge design experience.
"They found people able to comment from an engineering viewpoint, local authority engineer or otherwise," said Whitby.
The RIBA bridge competitions have been criticised previously for creating unworkable designs. Expedition engineering director Chris Wise said he saw no reason why the ICE is unable set up its own competition service.
"RIBA has a membership of 40,000 whereas the ICE has a membership of 80,000," said Wise. "Why can’t it get its act together and set up the administration [to deal with competitions]?"
He added that engineers should not only be getting involved at the evaluation stage but also at the initial stages when the brief is being prepared.
"They ask for an iconic bridge, but then [clients] give you the budget for a motorway bridge," said Wise. "The briefs could do with a degree of insight into what’s achievable."
RIBA competitions manager Louise Harrison was keen to stress that engineers are already involved in the RIBA bridge competition process.
"We always have an engineer on the judging panel. It would be inappropriate not to and very often the engineer would have sight of the brief," she said.