The cost of transforming the 2012 Olympic Stadium into legacy use has soared to £272M, it has emerged.
The London Legacy Development Corporation (LLDC) revealed the cost had rocketed from £190M last October.
Balfour Beatty is converting the stadium from the centrepiece of the London Games to the home of West Ham United Football Club, an event venue for UK Athletics and for other uses including the Rugby World Cup.
The work includes installing the largest single span cantilever roof in the world; constructing the warm-up track, spectator and hospitality facilities; and external landscaping.
The LLDC said today: “The costs reflect the huge scale of the works undertaken to transform the former Olympic venue from a temporary athletics stadium into a year-round multi-use arena capable of delivering world class sporting and cultural events. It will be the only stadium in the UK to meet Uefa Category 4 classification and be a fully compliant IAAF Category 1 athletics facility.”
The stadium work includes installation of a permanent roof, the largest of its kind in the world.
The 45,000m2 cantilevered roof required significant strengthening to support the 8km of cable net, 112 steel rafters, 9,900 roof panels and 14 light paddles each weighing 45 tonnes.
LLDC chief executive David Goldstone said: “We have invested in transforming a temporary athletics venue into a permanent world class multi-use arena that has a secure and long-term sustainable future. This has required a significant amount of work and innovative engineering solutions.
“Alongside the transformation work, the deals signed with British Athletics and West Ham United and the appointment of a stadium operator ensures the stadium will pay its way and not require any continuing subsidy from the taxpayer.”
A Balfour Beatty spokeswoman said the firm’s contract remained at the £189.9M figure revealed last year.