Architect Ken Shuttleworth has labelled the Shard an unsustainable “greenhouse”

One of the lead designers behind London’s iconic Gherkin tower Ken Shuttleworth has labelled the Shard an unsustainable “greenhouse”.

Shuttleworth – who has repeatedly claimed he would like the Gherkin to be designed differently to make it more sustainable if given the chance today – told the Ecobuild conference he didn’t think the Shard could stack up environmentally.

Shuttleworth said: “There will always be a desire to build tall, but we have a duty to make the next set of towers more energy efficient than before.”

He added: “Architects didn’t design with energy in mind in the 70s and 80s because it was so cheap but we now have to tackle energy efficiency.”

Dr Richard Mawer, a structural engineer at WSP who is on the Shard project team, came to the building’s defence.

He said the building had been awarded a BREEAM rating of ‘excellent’ and had automatic blinds on every window to mitigate solar heat gain.

He added that unlike many London buildings its high quality design was built to last. “It’s sustainable in that you don’t need to build it twice.”