Tongji University JOY GARDEN: Roof experimental garden with fun/ Urban Green
greencampus   Dec 12.2019


With the acceleration of urbanization, there are fewer and fewer green areas in high-density cities. As an important part of the city, green campuses play an important role in promoting the sustainable development of urban ecology. In today's increasingly three-dimensional development of high-density urban greening, roof greening provides a possible way to renew existing buildings on campus. After several months of repeated design and field installation from March to September 2016, we conducted an experimental roof garden renovation attempt on a small building roof of only 150 square meters in Tongji University.


The usable area of the roof is only 150㎡, the length is 23m, the widest point is 8.2m, and the narrowest point is only 4.4m. The shape is an irregular rectangle, surrounded by high-rise buildings.

The IUG team worked with relevant professional design teams, construction engineering and equipment technology supply partners, university labs and other R & D and innovation institutions to carry out detailed inter-professional collaborative design, and finally completed building structure load calculation, roof waterproof testing and Reconstruction, parametric design of wooden structures, roof rainwater collection and automatic irrigation system, lightweight roof structure substrate and many other technical applications.

During the design and construction of the original roof, there was a problem with the structure of the waterproof layer on the entire roof, and the sense of space was poor. Based on the above problems, before the roof garden was formally constructed, the IUG team retested the compressive strength of the floor concrete through tests, laid a waterproof layer again, carried out a closed water test, and changed the position of the drainage outlet.

199 pieces of lightweight wooden frame structure realize functional division

The space interface of the roof garden uses digital technology to generate three-dimensional curves and detailed dimensions and contours. Finally, 199 different basic units of wooden frame are designed, realizing a new space with multiple areas such as seats, fences and hanging points.

After the calculation of the load, the part of the pedestrian platform on the roof is totally elevated, and the detailed roof vertical section design is combined with the space function division requirements of the roof garden to meet the requirements of rapid drainage of the roof on the basis of ensuring the stability of the structure.

Careful machine hidden in the gardenThe IUG team incorporated many small details into the roof garden design, making walking the experimental garden a pleasant surprise and fun experience.

The roof garden of JOY GARDEN shows the combination of three-dimensional greening of the green campus building, the concept of ecological cycle and technology. The power and water required for plant irrigation and conservation are taken from nature and used for nature. Monitoring and system operation.

Through collaborative design with professional partners, the experimental roof garden is equipped with a water storage tank and a control box on the ground floor of the outdoor. It integrates rainwater collection, purification systems and automatic irrigation systems, and provides power to the system through solar photovoltaic panels. The system accurately calculates the amount of rainwater and sprinkler irrigation, and realizes the integrated functions of solar photovoltaic power generation, roof rainwater collection and purification, and automatic roof irrigation.

At present, the renovated JOY GARDEN roof garden, as a small-scale experiment of green campus reconstruction, will gradually combine a series of three-dimensional green field teaching, a series of three-dimensional green plant evaluations and special tests to carry out a series of follow-up experiments on campus green reconstruction. It also provides a place for teachers and students to ascend to rest.

The IUG (Innovative Urban Green) is an international multi-disciplinary joint research and innovative design working group established by Associate Professor Dong Nannan, Department of Landscape Architecture, School of Architecture and Urban Planning, Tongji University. Technology and environmental construction research innovation. Special thanks: Teacher Mary Polites, Teacher Shen Jie for their support and consultant participation.


Lat: 31.23
Lng: 121.47
Region: Asia
Scale: City
Field: Environment
City: shanghai