British architect Crispin Wride has released his own concept for a Garden Bridge in London, which he claims is more cost-efficient than Thomas Heatherwick's proposal and more imaginative then the alternative suggested by Allies and Morrison.

Wride wants to utilise the redundant piers beside Blackfriars Bridge to create a series of four leaf-shaped platforms across the River Thames, each containing its own garden.

These platforms would sit between the existing road bridge and the neighbouring railway bridge. They would be raised up to offer views west along the river, and would be connected by additional lightweight bridges.

Called the Blackfriars Garden Islands Bridge, the structure could also include small pavilions, creating cafes, galleries or event spaces.

"It would create a dynamic new experience of crossing the river, not a continuous uneventful route from one side to the other but a series of linked garden islands and pavilions, each potentially with its own unique identity to animate the experience," explained Wride.

The project – one of Wride's first since launching his studio, CWADS – responds to the ongoing controversy surrounding the Thomas Heatherwick-designed Garden Bridge, which is championed by actress Joanna Lumley.

Questions have been raised over a number of issues surrounding the Garden Bridge, including funding sources and the procurement process that led to Heatherwick's appointment.

It is expected to cost £175 million, with £115 million from private donations and £60 million of public money already committed. Critics have suggested that taxpayers will end up paying for the remaining £30 million.

Last month architecture firm Allies and Morrison proposed a cheaper and less contentious alternative that involved reconfiguring Blackfriars Bridge, making room for a verdant garden along one side.

Wride's design is in a similar vein, but is intended to do more to "change the experience of crossing the river".

"Rather than just providing a route from one side to the other, the concept is based upon the idea of stepping stones or a series of islands," he told Dezeen.

"The island decks form an archipelago, each island occupying one of the pairs of existing piers and linked to its neighbours and connected back to the road bridge at the piers, to enhance access and flexibility of use of each space."

The architect worked with structural engineering firm OPS to develop the design.

He claimed the 45-metre-long platforms could be prefabricated in a factory, allowing a quick and inexpensive installation.

These would then be cantilevered off the existing piers, which are left over from a structure pre-dating the current Blackfriars Bridge and the railway bridge that runs alongside it.

Heatherwick first unveiled his design for the Garden Bridge in 2013.

It is scheduled to complete in 2018, in line with a strict timescale that requires it to be in place before work starts on a major new sewer.

An enabling project was due to start imminently at Temple tube station, but was temporarily frozen by London mayor Sadiq Khan earlier this month to ensure no more public money is committed to the scheme. The mayor has pledged to make the project "more open and transparent".

Images are by Crispin Wride and Alex Quintus.