Build costs on the 2012 Olympic Velodrome were slashed by £1.5m by changing the roof design, a new government report has found.
The building, which was built by main contractor ISG, was originally designed to have a steel arch roof but the team changed this to a lighter cable net design because of poor ground and uncertainty about how the original design would be erected.
The change not only saved money but also used about 1,000 tonnes less steel (a 10 per cent cut), cut carbon dioxide used in making the materials by over 25 per cent and reduced the build time by six months.
The figures were revealed in a report, The legacy: sustainable procurement for construction projects, published by the Department for Environment, Food and Rural Affairs published last month.
The report also said that obliging all contractors in the Olympic Park to use the sustainable concrete sourced by the ODA, which contained at least 20 per cent recycled material.
About 170,000 tonnes of recycled and secondary aggregate was used which cut the carbon dioxide emitted in making the concrete by 30,000 tonnes (24 per cent).
Contractors had feared that being contractually tied to the Olympic Delivery Authority’s chosen concrete supplier could result in higher costs largely because of the costs of handling the material at the Olympic Park railhead. But the ODA allayed these worries by negotiating with the railhead operator to reduce the handling fees passed to construction suppliers, the report said.
The ODA linked the remuneration of some key ODA staff to sustainability targets and allowed contractors to share in savings in order to incentivise them to meet sustainability goals.
The DEFRA report found that the ODA’s publication of sustainability goals ensured they could not be rejected because of costs and it monitored contractors’ performance against targets.