News: groups of eight people or more will have to apply for permission to cross Thomas Heatherwick's proposed Garden Bridge in London in a move to discourage "protest groups" from occupying the structure.

Lambeth Council – one of two London boroughs responsible for whether the Garden Bridge gets built – granted planning permission for construction last week on the condition that large groups will need to apply in advance for permission to cross.

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Architecture news site BD Online (BD) today revealed details of the planning conditions applied to the project.

"All groups of eight or more visitors would be required to contact the Garden Bridge Trust to request a formal visit to the bridge," said the planning document quoted by BD. "This policy would not only assist visitor management but also would discourage protest groups from trying to access the bridge."

However, The Garden Bridge Trust established to raise funds for the £175 million project, which is designed by Heatherwick Studio, alongside engineers Arup and landscape designer Dan Pearson, said it would not charge for admission.

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BD reports that the 367-metre bridge will cost £3.5 million a year to operate and maintain, but that "it is not the trust's intention to introduce an admission charge".

It is expected to be closed for 12 days a year for fundraising and community events, with revenue to go towards the bridge's upkeep, and will only be accessible for 18 hours of the day.

The council document also confirms that cyclists will not be welcome on the bridge. "Cyclists would be able to push bikes over but not ride," it states. "If cyclists were allowed to ride, to provide a safe pedestrian environment it would be necessary to incorporate segregated cycle lanes or wider shared paths. This would result in a much reduced planted area and erode the benefits of the bridge as a green space."

The Garden Bridge is set to span the River Thames between the South Bank and Covent Garden, offering a generous promenade of trees and shrubs supported over a pair of fluted piers.

Lambeth Council granted conditional planning permission for the project in a meeting last week, with a vote of five to two. It still needs approval from Westminster City Council, who is expected to review the plans before the end of the year.

Construction will need to begin next year to avoiding clashing with the proposed Thames Tideway Tunnel. The bridge's opening is pencilled in for 2018.