Anchoring the overall development, this project engages the natural forces of the site and celebrates their potential. The project addresses the park as a 'quiet zone'. Its eastern face looks out at the main street's 'loud zone', and its northern civic edge relates to the master plan corridor, where most retail and commercial functions are planned. The southeast corner of this site is linked to a future train station. The commercial and residential towers anchor each side of the site, and natural movement is caught between them. Northstar's 100-meter office tower stands on the intersection corner as a landmark while the apartment tower is on the southwest corner, oriented towards the park and southern light. Daylight pours through skylights between the towers towards the ground, highlighting entrances in the north, south and west sides of the site. Project is located on the ‘fifth ring’ of the Beijing city, close to Olympic park area. On its west is a big leisure park and other cultural facilities, whereas on its east are the main streets and a new subway station. Given this prime location, the project serves as an anchor of this larger master plan, and links directly to the Beijing transit network. Two 25-storey high office towers, ‘the Rocks’, are situated on top of a 7-storey mega retail podium. The two office lobbies are situated on the ground level, where one can gain easily access from the major streets. The retail podium was being designed as a retail experience where people can sit and hang out apart from shopping. Big anchor stores were placed on the two floor plates underneath the towers, where other retail shops were planned as small rock-like forms, which were being placed strategically in response to the circulation movements and flows from the surrounding areas. Circulation paths inside the mall are planned like an artery system inside an organic body, or like running water flows down a stream, which makes walking inside the mall a unique spatial experience. Externally, the different floor plates create terraces and stepped landscapes, where one could sit outside and enjoy the surrounding environment. The main feature that aims to improves accessibility and wellbeing of the people is no doubt the canyon like atrium space. Instead of making the retail podium a luxurious and exclusive shopping experience, this project instead, aims to make retail shopping more like a cultural experience and turns the atrium space as an interior park space, where people can take leisure walk inside, and at the same time still enjoy the organic beauty of nature. The design thus opens up several entrances to the surrounding and let people naturally ‘flows in’ rather than marking a grand entry. Atrium space is being seen as a direct continuation of the adjacent park and the Beijing city. This design promotes accessibility and linkage of nature and man-made environment, the city and the individual. Due to its prime location in the district, the project was required to provide a bridge link to an elevated subway station, which is located at the south-east corner of the site. The design see this requirement as one of the natural forces of the site and made use of this required connection to create major circulation path, which flows throughout the entire atrium space, and to the other side of the podium. The design adopts a free-form skylight as a connection to external environment and as the main architectural feature in the retail atrium space. This undulating skylight spreads throughout the entire atrium, provides a good source of natural lighting and in turn reduces the electric loads for interior artificial lighting. Insulated glass units with a Low-E coating were used at the commercial towers above, whereas laminated glass is used at the podium, which maintain a good thermal and acoustic control in the interior space throughout different seasons. Reflective coating was also added on the glass surface to further reduce solar heat gain and in turn reduces the air-conditioning loads. Innovative structural solutions and technologies were used in these areas to achieve the desired spatial quality: 1. Undulating skylight – The skylight is being conceived as a moving form and changes its profile as one flows down the space. 3D truss system is being used to support the skylight. Triangular module is used so that the glass panes can be made typical to ease construction, but at the same time, allows flexibility in form-shaping with maximum light transmittance and flexibility. 2. Cantilever Bridges – The retail podium was designed as individual ‘rocks’ with link bridges. These link bridges were being placed at different locations at different plan levels. To allow these long span bridges inside the atrium space without any column support under, these bridges were turned into a steel truss frame so that it can span across the atrium without any intermediate support 3 Twisted façade and sloping surfaces – On the external elevations, this design adopts many twisted planes, and tilting surfaces. The traditional beam and column structural system with direct vertical support cannot be adopted in these areas anymore. Instead, sloping columns and transferred beams were being used to allow the floor plates to slide and twist once they go up, and allow the being to tilt outwards without having any column support under. The site is situated next to a leisure park and cultural facilities. And the design tries to take advantage of this existing features and ‘reuses’ them as an extended part of the retail podium. There is no fixed boundary between the park and the mall. Man-made space is now not competing against nature, but is being conceived as a continuation of its immediate natural surroundings. Through careful play of light and shadow, views, natural movements, circulations and linkages to the greater city, the design promotes sustainability and encourages people to interact with other people, with nature, and with the city. The projects a true success in leading the sustainable development of the Beijing city.