Toranomon Hills Tokyo
Japan’s Vertical Garden City
The Toranomon Hills Tower, one of Tokyo‘s tallest skyscrapers, is flanked by two impressive new companions: a 36-storey, 185-metre-high commercial tower and a 54-storey, 220-metre-high residential tower, Japan‘s tallest residential tower.
The two new towers blend into the surrounding neighbourhood by respecting the taller central tower while designing their own urban response. They echo the greenery of the adjacent parks and the gardens of the historic Mt. Atago shrine, fanning out in steps towards the ground floor zone. The design is based on the concept of the vertical garden city. The integration of green spaces on multiple levels of the development not only enhances the quality of outside spaces for the public and the residents/workers, but also contributes to the reduction of air pollutants, the heat island effect and enhances the microclimate.
The design of the high-rise buildings contributes to the image of the urban quarter and fulfills multi-layered functional requirements. Decks between the buildings create connecting links. Landscaping in front of the two towers provides generous open areas. The stepped terraces allow the viewer to follow the events on the lower levels and create a multi-layered urban landscape complete with rich vegetation and public recreational areas. In the residential tower, each flat has a plant trough and its own balcony, while the office tower has a total of 6,500 m2 of green space, plus 154 large trees. This achieves a green replacement rate of 64.5 percent and a CASBEE „S“ rating. Other environmental technologies, such as combined heat and power, grey water recycling, high-performance glazing, rainwater collection, photovoltaics, and highly efficient lighting and mechanical service installations also contribute significantly to making the building as environmentally sustainable as possible.
The horizontal ledges of the two towers are particularly emphasised in the design concept. These projections shade the fully glazed façades and create a balance between the need for maximum daylight and the requirements for low energy consumption in a high-performance building. Full-height windows are the key element for the bright and spacious design of each floor. The terraces and decks form public spaces and landscaped areas for leisure activities and merge seamlessly with the horizontal projections of the upper floors. The horizontal ledges therefore fulfill several functions: They provide solar screening, surfaces for planting, and can be used as balconies. The integration of the planted areas on different floors creates additional open areas, reduces air pollution and improves the microclimate. With its colours, scents and sounds, the landscape stimulates the senses. Waterfalls reflect the light and enrich the urban soundscape with natural sounds.