People visit paper houses in the Chongqing University, Chongqing, southwest China, May 21, 2013. Fourteen paper houses, made up with recycled paper by more than 200 freshman, were displayed in the Faculty of Architecture and Urban Planning of the university on Tuesday. (Xinhua/Chen Cheng)

People visit a paper house in the Chongqing University, Chongqing, southwest China, May 21, 2013. Fourteen paper houses, made up with recycled paper by more than 200 freshmen, were displayed in the Faculty of Architecture and Urban Planning of the university on Tuesday. (Xinhua/Chen Cheng)

Photo taken on May 21, 2013 shows the paper houses in the Chongqing University, Chongqing, southwest China. Fourteen paper houses, made up with recycled paper by more than 200 freshmen, were displayed in the Faculty of Architecture and Urban Planning of the university on Tuesday. (Xinhua/Chen Cheng)

Children play in a paper house in the Chongqing University, Chongqing, southwest China, May 21, 2013. Fourteen paper houses, made up with recycled paper by more than 200 freshmen, were displayed in the Faculty of Architecture and Urban Planning of the university on Tuesday. (Xinhua/Chen Cheng)

People visit paper houses in the Chongqing University, Chongqing, southwest China, May 21, 2013. Fourteen paper houses, made up with recycled paper by more than 200 freshmen, were displayed in the Faculty of Architecture and Urban Planning of the university on Tuesday. (Xinhua/Chen Cheng)

Students take photos in a paper house in the Chongqing University, Chongqing, southwest China, May 21, 2013. Fourteen paper houses, made up with recycled paper by more than 200 freshmen, were displayed in the Faculty of Architecture and Urban Planning of the university on Tuesday. (Xinhua/Chen Cheng)