The Garden Bridge is a proposed public bridge over the River Thames in London. Designed by Thomas Heatherwick, and to be delivered by Arup, the concept is for a footbridge featuring trees and other vegetation. The project has proved very controversial for several reasons, including escalating costs, the tender process, the need for a new bridge, protection of existing views, and the commercialisation of public space.
The idea of a ‘floating paradise’ garden bridge was first raised by the actress Joanna Lumley in the late-1990s. The idea did not gain any momentum until 2012 when she began to approach Transport for London (TfL) and the then-Mayor of London Boris Johnson, who was keen to find a ‘legacy project’.
The draft business plan from the Garden Bridge Trust stated that the bridge would be open to the public for 18 hours a day, and would close for private events on 12 days of each year. It proposed that on every summer weekend the rooftop of the landing podium would be rented for commercial purposes.
A full planning application was submitted in May 2014. The aim was for construction to begin in 2015 and to be complete by 2018, subject to receiving planning permission and raising the required funds. Lambeth and Westminster City Councils conditionally approved the application in late-2014, followed by Johnson’s official approval.
As of October 2016, the bridge was estimated to cost a total of £185 million. This included £125m of private money (including charitable gift aid) and £60m of public money, of which £30m was from TfL (of which £20m is to be repaid over 55 years), and £30m from the Department for Transport.
The bridge will be 367 m (1,204 ft) long and cross the Thames between Waterloo Bridge (200 m to the west) and Blackfriars Bridge (300 m to the east). It will project from the roof of Temple tube station on the north bank to Queen’s Walk on the Southbank area, currently a public open space.
The structure will be made of concrete, steel and cupronickel (a composite of copper and nickel). The warm colour of the cladding is intended to provide a contrast to the steel and concrete structures on both sides of the river.
The bridge will be planted with 270 immature trees as well as shrubs and wildflowers. The south end will include plants such as willow, birch, violet and primrose; while the north end will include wisteria, roses, irises and summer snowflakes. As a means of limiting the structural wind loading, the trees will be maintained so as not to exceed heights of 15 m at bridge piers and 2 m near the bridge landings.
The project has been beset by numerous controversies since 2012.
In an attempt to try and counter some of these issues, the Garden Bridge Trust has provided a 'Mythbuster' on its official site.
The most prominent concerns are:
Attention has been focused on a business trip to San Francisco that the then-Mayor of London Boris Johnson with his chief-of-staff and deputy Mayor for Transport in February 2013. This trip, listed as private, was intended to promote sponsorship opportunities for the bridge.
The designer Thomas Heatherwick was also invited to attend the meeting to discuss his design concept, despite TfL having not at this time formally invited design bids.
There was also concern over the fact that Heatherwick’s design was selected by one official, as opposed to the panel required for major infrastructure projects.
In September 2015, Lambeth Council suspended their negotiations with the Garden Bridge Trust over the terms of the lease, which would be required at the Southbank end of the bridge. Necessary lease modifications were reported as having been put in place by March 2016.
The housing trust which holds the long term lease over the southern landing section, Coin Street Community Builders, have delayed giving permission. However, in response to anti-bridge campaigners, they have indicated that it is not in a position to oppose elected governments’ decisions.
It has also emerged that due to Johnson’s desire for urgency in starting work, contingency plans were created to turn the bridge into a pier were the necessary permissions for the southern bank not given.
 Rules and restrictions
Consternation has also been raised over the ‘draconian’ rules and restrictions that have been proposed by the business plan. In November 2015, planning documents showed that there would be heavily controlled public access, with visitors’ phone signals tracked to alleviate overcrowding. In addition, there would be a video surveillance system and security staff with limited police powers that would give them the right to issue on-the-spot fines.
The bridge rules were stated as prohibiting: ‘Any exercise other than jogging, playing a musical instrument, taking part in a 'gathering of any kind', giving a speech or address, scattering ashes, releasing a balloon and flying a kite.’
When first promoted, the Garden Bridge Trust claimed that private sources would be sufficient to finance the £60m project. However, a total of £60m towards the capital cost was committed from public funds, with £30m pledged from TfL funds by Johnson, and £30m pledged by HM Treasury.
In the meantime, the proposed cost of the bridge had, by August 2015, escalated to £185m. Officials began raising concerns, with contrasts made between the new cost and the Millennium Bridge which had been built for just £22m.
In July 2016, the new Mayor of London Sadiq Khan, who had claimed while campaigning that he would scrap the project, said that no more public money would be spent, and that preparatory work had been halted for City Hall to review the financial situation.
Having taken office at City Hall, Sadiq Khan announced that the bridge was ‘too expensive to cancel’, with almost £40m spent without any on-site construction work having begun. Khan said:
"If we were to cancel the project today … [the costs] would have been spent for no benefit at all for Londoners. However, if we complete the Garden Bridge, then not only will TfL be paid the £20m loan by the Garden Bridge Trust, but they will also pay roughly £22m in VAT to the government. That would leave an ultimate cost to the taxpayer of £18m for completing the Garden Bridge, significantly lower than the £37.7m cost of cancelling it.
"It is clearly in the interest of taxpayers to complete the Garden Bridge."
In September 2016, Khan announced a formal review into the project’s value for money to be led by Dame Margaret Hodge.
In October 2016, the National Audit Office (NAO) published the results of its inquiries into the £30m funding provided by the Department for Transport. It concluded that the Department had committed the funding despite assessing the original business case as having a significant risk of representing poor value for money. Providing the funding in a block grant to TfL left the Department with limited oversight of its own support to the Garden Bridge Trust, according to the NAO.
In January 2017, the Garden Bridge Trust's annual accounts showed a shortfall of £56m, leaving them to state that they were "unable to conclude [the bridge] is a going concern".
Despite the Trust saying that trustees still expected construction to start in 2017 - necessary as the planning consents expire in December - the Trust needs to raise an extra £56m from donors. This is money that can be spent by the Trust immediately, and so poses a risk for donors if the project is eventually cancelled. The Trust has stated that any additional funding would not be repayable "if the project is not able to proceed" in the first half of 2017.
Despite Sadiq Khan pledging that no more taxpayers' money would be allocated to the project, nearly £40m stands to be lost if the project is cancelled.
 Related articles on Designing Buildings Wiki
- Bridge construction.
- Bridges of the world.
- Constraints on construction projects.
- Garden Bridge - alternate design.
- Landscape urbanism.
- Pier 55, New York.
- TfL’s Thames crossing plans.
 External resources
Featured articles and news
The first CIC briefing of 2017 covered a construction economic forecast, illegal migrant workers, and a Crossrail 2 update.
Have a look at this competition-winning proposal for a new mountain range-like complex in China.
BRE and Environment Agency join forces to try and build flood resilience into the fabric of Britain.
This spherical house in Vienna is considered a micro-nation - the Republic of Kugelmugel.
Commission has been awarded for a floating church designed after a pair of organ bellows.
"Teachers and schools do not understand construction very well" and need to do more, according to Carol Lynch.
ICE examine the use of structural engineering codes and the use of withdrawn British Standards.
BREEAM expands its digital horizon with first online dynamic syncing of assessment data.
RIAS criticise the transfer of responsibility from construction professionals to other parties less involved with the design process.
Building Automation and Control Systems (BACS) market in North America continues to grow.