Barratt has replaced architect Halpern with Allies and Morrison as the designer of a 900-home scheme in London after pressure from London’s new architectural watchdog.

The London Development Agency (LDA) selected Barratt to develop the site in Bromley-by-Bow, east London, earlier this year using a design by Halpern.

But the LDA’s recently established Design for London unit told Barratt that it wanted to beef up the design team for what it sees as a showpiece low-carbon development.

A Barratt spokesman confirmed this week that Allies and Morrison would take the scheme forward and that Halpern was no longer involved.

He said that the company would continue to work with Halpern in the future. He said: “Barratt doesn’t want to cast any aspersions on Halpern. We’ve worked with them before and we will again.”

A Design for London spokeswoman said: “We weren’t responsible for the original architect being dropped. The decision to drop the original architect was Barratt’s.”

But she admitted that the unit had a hand in the process. “Barratt put in a bid we thought was strong, but we felt that the quality of the design team needed to be strengthened.”

She said that Design for London was keen to ensure that the development set a benchmark for high quality architecture in the area, which is close to the 2012 Olympic Park.

Tim Quick, a Halpern director, said: “We’re gutted to be kicked off after so much hard work. There was absolutely no feedback about our design. Instead of getting together to discuss any issues it has with the design, the LDA has simply told the client to drop us. This can’t be the best way to organise these competitions.”

The LDA originally planned 800 homes, but this is expected to increase to nearly 900. Half will be affordable and more than a quarter will have three or more bedrooms.