An eco-friendly and pleasant living environment is key to rural revitalization. To promote green buildings, the renovation standard of living environment should be improved and requirements on protecting the natural environment should be met. At present, China has a complete set of construction system for urban buildings and excels in the R&D and promotion of green buildings around the world. However, most of the rural dwellings built during the early agricultural period are riddled with issues such as poor thermal insulation and extremely high energy consumption. Therefore, traditional green technologies can no longer ensure an eco-friendly and pleasant living environment while preserving local culture. Liu Jiaping, an academician of the Chinese Academy of Engineering and a green building expert, and his team have conducted a lot of research on green buildings with low energy consumption and low-carbon emissions that meet the characteristics of rural areas, exploring new ways of designing and constructing green rural houses to solve the mismatch between traditional houses and modern living standards.

Fig. 1 Liu Jiaping, Academician of Chinese Academy of Engineering (source: CCTV-1 program ‘Open Lecture’)

Rural residents are discouraged by the harsh environment of rural dwellings such as traditional cave dwellings with inadequate lighting and poor ventilation, buildings suffered from strong earthquakes, and high-altitude dwellings with substandard heating. With years of exploration and practice, academician Liu Jiaping and his team have reshaped many old rural houses and given them a new look so that villagers can lead a more comfortable, greener, and better life.

Twenty-two years old houses that still satisfy the residents

In September 1995, academician Liu Jiaping's team came to Zaoyuan Village of Yan'an to renovate the traditional cave dwellings in the Loess Plateau area. To fix the problem of poor ventilation and lighting in the rear of the buildings, the team revamped part of the buildings into two stories, which had greatly improved the lighting. At the same time, ventilation and light wells were set up at the rear of the buildings to compensate for inadequate lighting and improve the indoor ventilation efficiency and air quality. With the adoption of new construction materials and methods, the traditional brick cave dwellings in Zaoyuan Village of Yan'an got a "gorgeous transformation", ridding people’s stereotype of cave dwellings. The renovated cave dwellings can maintain good lighting even after 22 years, which is something the villagers are very satisfied about. Twenty years have passed, the villagers of Zaoyuan Village still live peacefully in their cave dwellings when buildings are erected all around. Their happiness is a vivid proof that "living in peace is the only way to working in contentment".

Fig.2 Building and environment

Houses that will stay in fashion in the next three decades

In May 2008, academician Liu Jiaping and his team came to Daping Village, Tongji Town, Pengzhou City, Chengdu, for post-disaster reconstruction. The team fully factored the local ecological environment and cultural customs into their reconstruction plan. Special designs were made for the location of the fire pit, that for the hot pot and outdoor tea and chats. Through continuous discussions with the local villagers and repeated modifications based on the comments made, the team finally designed the post-disaster reconstruction plan to the satisfaction of all villagers. "Houses that stay in fashion in the next three decades must be eco-friendly houses that offer a pleasant living environment," said Academician Liu Jiaping.

Fig. 3 The new rural houses after the disaster

Houses that stay warm without the aid of equipment in the alpine region

In 2005, to solve the heating problem of traditional high-altitude houses in Tibet, academician Liu Jiaping invited ten professors and doctoral students to go to Lhasa and jointly design a house with ultra-low energy consumption and that mainly depends on solar energy for heating. After extensive field research, the team set the appropriate design criteria that would allow a building to reach an indoor temperature of 10 to 20 degrees Celsius even without any heating equipment. The new high-altitude houses are built with abundant "sunlight elements". The thermal collection and storage wall interworks with the rooftop solar collector system to collect and store thermal energy during long daylight hours. In addition, the sunroom and transparent exterior windows accumulate the daily heat entering the room to improve the indoor thermal environment during the heating period. The smart design allowed the high-altitude houses to "successfully hold hands" with the sun, providing a constant source of warmth for the herders in the extremely cold environment. At the same time, the team allowed the villagers to build their houses themselves with the help of modern craftsmen, which ensured quick and smooth construction, reduced cost and ensured quality.

"All scientific research comes from the demand. The demand of the residents and society is then transformed into technical and scientific problems, which are addressed later." With such a demand-oriented research attitude and a committed and down-to-earth spirit, academician Liu Jiaping and his team have built, step by step, new cave dwellings with sunrooms in two stories on the Loess Plateau, exclusive and customized eco-friendly homes in the earthquake-stricken areas, and brand-new houses with solar heating on the snowy plateau. These rural ecological dwellings, which take into account cultural traditions, customs and ecological environment, have drawn the “base color” of China’s rural revitalization.

Fig. 4 The new rural houses after renovation

The traditional houses in China's rural areas exist because of their unique mode of production and represent the skills and culture of the people who built houses in the region throughout its history. Therefore, houses in each place maintain different styles. When the traditional houses built during the early agricultural period are no longer compatible with modern living standards, green buildings with low energy consumption become the "key" to unlock houses with pleasant living environment in the new era. Green buildings in rural areas should not only improve the energy consumption pattern and environmental impact of houses, but also preserve nostalgia. Different ethnic groups and regions should retain their distinct styles. In the future, China will have a beautiful countryside with different styles, meeting the standards of health, comfort, and environment. Preserving nostalgia is not only about expecting a better hometown, but also about using what we have learned to transform our hometowns.

Fig. 5 Academician Liu Jiaping participated in the recording of CCTV program ‘Open Lecture’

Academician Liu Jiaping expressed his hope to see joint efforts and hard work to achieve China’s urbanization goal, that is, 60% of its 1.4 billion population live in urban areas. Make sure everyone knows where we come from, and more importantly, where we are heading to in the future.