A group of foreigners, including overseas students and experts, visited factories that seek environment-friendly solutions during a trip to understand how Changsha is transforming itself into a resource-conserving and environment-friendly society in Changsha, Hunan province, on Wednesday.

The foreign representatives showed a great interest in an enterprise which uses new technology and eco-friendly ideas in construction.

The Broad Homes Industrial International Co, Ltd advocates building houses like automakers build cars - separately constructing parts to improve the quality of the building and using less energy during the process.

The representatives visited the production line where many pieces are made as individual parts. According to the company, the walls are made first then the rooms take shape. The building, the company claims, built this way can last more than 100 years.

According to a staff member at the construction site, there is no dust, noise or wastage of water and material when the walls are build.

The company said the new method reduces the usage of five tons of construction waste to build one square meter of construction.

To build a 125-square-meter house with the new method, Broad claims it saves 70 percent of energy, 20 percent of materials, 80 percent of water, 60 percent of time and 20 percent of space compared to houses constructed in traditional way.

In March, Broad became famous when it completed a 57-storey skyscraper in 19 days in Hunan. Its time-lapse video of the construction and its innovative method left people amazed.