The Shanghai No 3 Steel Factory, which once made products vital to the mainland economy, will get a new lease on life with plans for the building to be a stage for cultural performances during the World Expo in 2010. The factory on the banks of the Huangpu River was left to rust when the vast steel sector was consolidated by the state. It will be part of Shanghai's record on historic preservation, which is best described as mixed. The city boasts the successful Xintiandi area, which features old architecture, but it has also razed entire neighbourhoods in its race to modernity. Officials are coy about whether any heritage buildings were destroyed to clear the expo site, but the planned preservation of at least 16 structures on the site is an unprecedented effort - especially since the municipal government, not commercial interests, is behind the restoration. She Zhipeng , assistant manager of construction for the Shanghai World Expo Co-Ordination Bureau, said rising costs were one reason for reusing old buildings on the 5 sq km site. Higher prices for steel and building materials had put pressure on the 18 billion yuan (HK$20.24 billion) construction budget. 'Demolishing, removing the debris, building again - they all need money. We want to save,' he said on the site of the future cultural venue. New reinforcements are already visible on the building. 'The Shanghai World Expo has specially selected a batch of old factories with historical significance for renovation.' Renovated buildings will cover around 350,000 square metres of floor space, out of a total of 2 million square metres. The last two expos - in Zaragoza, Spain, this year and Aichi, Japan, in 2005 - did not reuse old structures. Zaragoza was sited on former farmland, and Aichi is a suburb. The Shanghai No 3 Steel Factory dates back to the 1950s, but some structures of the Jiangnan Shipyard on the site are more than 100 years old. Organisers are still trying to determine whether two other buildings are salvageable, which would bring the total to 18. They said construction on all venues, new and renovated, would be finished by the end of next year. 'Safety is our first concern,' Mr She said. With up to 800,000 visitors per day expected during the expo peak, tests were needed to see if old buildings could stand up to the foot traffic. Organisers are also struggling with the legacy of pollution caused by old factories. Shanghai has responded by hauling away a million cubic metres of soil and replacing it with earth trucked in from surrounding areas. 'To put environmentalists' minds at rest, the government has invested to change the soil,' Mr She said.