SHANGHAI -- A fifth of the world's construction cranes were at work here in the mid-1990s, pushing this city's skyline up from the banks of the Huangpu River. High-rises went up fast, but were generally not made to last. Steel was comparatively cheap and electricity consumption was an afterthought. Shanghai and other big Chinese cities are still rising by the block, but construction practices are shifting in the country's emerging market economy. Developers are starting to embrace "green" design standards to meet tougher building codes as well as give their projects an edge in the crowded marketplace.