The Housing Department should set up a central godown to store leftover construction materials that would otherwise end up in landfills, an environmental group has suggested. Friends of the Earth said the materials could be kept for later use by contractors, or even shared out among other construction firms. Edwin Lau Che-feng, the group's assistant director, said the Housing Department should maintain a central storehouse to cut waste. 'A Web site with the residual materials information could be developed for all contractors to see if they could take up the materials not required any more by others,' Mr Lau said. However, the Housing Department and a government contractor said the plan was impractical. Hip Hing Construction yesterday donated 400 tones of left-over tiles to three non-government groups. The tiles, left over from the construction of six public housing estates, have been kept in Hip Hing's 100,000 square feet godown for months and would have otherwise ended up in landfills. Kwong Chee-keung, the senior manager of external affairs for the contractor, said the excess tiles were the result of a policy having a two to three per cent margin for error in ordering building materials. 'Other than tiles, we have also baths and sinks as well. No one wants to buy them. Sometimes we ask our staff to take them away for [their own] home refurbishing,' he said. Mr Kwong said it would be difficult for contractors to share leftover materials, as they would be providing help to their competitors. Maxwell Chiu Ying-cheung, a maintenance surveyor with the Housing Department, said the central godown idea was impractical and it was contractors' responsibility to minimise waste. Local landfills are expected to be full within 10 years. Hong Kong generates about 6.5 million tonnes of wastes each year.