Takenaka's new building in Toyocho combines office in different buildings.

Dispersed hybrid air-conditioners on exterior wall braces maintain a comfortable office environment.

Artwork by Masanori Sukenari at the entrance Ligth-filled entrance hall with glass ceiling Open space enhances collaboration. Massive space enhances internal communication. Rooftop graden reflects environmental technology. Advanced external wall and new ceiling system The new Takenaka Tokyo Main Office Building has been constructed in Toyo-cho, and business there began from November 24, 2004. While unifying three separate Tokyo offices and designed for more efficient business, the aim was also to strengthen the links with Group companies which were already based in Toyo-cho. The main theme of the plan was "sustainable works." The company's proposal was to "plan architecture where the company, with the customers, could aim for the creation of space in harmony with the environment." The idea was from the planning and design stages through to the construction and operation of the building, to realize the goal of improvement of the total environmental quality and reduction in the load on the environment, in the cost and design. The implementation of this plan was positioned as the company's own experiment in providing solutions to customers. Because of the development of various solutions within the company, and with the multitude of business forms, there was a strong desire for an office space which was able to respond even faster to the development of creative business. On the one hand, there is an immediate social need these days to meet the requirements of global environmental protection. A "programming method*" was therefore used to set the office concepts, and the main targets that were extracted pursued a highly-efficient and high-quality work place, a reduction in the load on the environment, as well as cost performance. In order to realize these aims, increased integration was given to the equipment and structural systems and architecture. The main aims were creating a new office style with improved office communication, maintaining a high level of both environmental quality and performance, the new development of low-cost parts, a reduction in LCC, and the building of an environmental performance maintenance system after construction, all designed for the development of this "sustainable works." The building does not have a spatially and structurally hardened part like a core, as do conventional office buildings. The functions that are conventionally made up in this core are laid out in the form of a central row in the floor plan in an open manner to the office zone. In addition, three light wells and an open staircase are inserted in a straight line into this central row to let in sunlight, and there is good visibility between the upper and lower floors and even on the same floor, designed to improve communication within the company. Furthermore, meeting zones have been laid out in the central row, promoting a function of collaboration with the open staircase and a break area, increasing office activity.

The structure uses a uniform span measuring 10.8 by 10.8 meters, different to conventional office modules. The building uses a simple structure made up of CFT columns with a diameter of 500 millimeters, an "external bracing structure" with buckling-restrained braces laid out, and "universal floor beams" made up girders and beams of a uniform beam depth of 450 millimeters. With a disperse layout of air conditioners in the exterior brace sections, outside air is directly drawn in from the exterior wall louvers, exhausting through the light wells, the building uses a four-mode hybrid air-conditioning system using natural ventilation. The exterior expression is a design that reflects the thinking behind the external bracing structure with the space that opens up from that, as well as the equipment system. Also, with the universal floor beams, the air-conditioning ducts do not penetrate the beams, but are hung under the beams, so with a standard office building floor height of 4.1 meters, a minimum 3.0-meter ceiling height has been maintained. The direct ceiling "new ceiling system" consists of punching metal underneath covers and lighting fixtures. Various methods have been used in the aim of a reduction in the load on the environment, including using corrugated cardboard ducts, using recycled materials such as the specially-developed exterior PCa boards using the waste glass from optical fiber and recycled aggregate, using solar power such as with rooftop heat-collection ducts on the cafeteria-wing rooftop (used for cafeteria heating and ventilation), daylight collectors installed in the light wells, and automatic light controls, and using intermediate rainwater. The building also has a highly-efficient system which conserves energy and reduces LCC, by using the hybrid air-conditioning system using natural ventilation, thermal storage technology such as ice thermal storage (CLIS) and low-temperature water thermal storage, heat delivery using large temperature gap water delivery, and low-temperature and high-temperature wind delivery. Compared to ordinary office buildings, this realizes a 50-percent reduction in both the amount of CO2 emissions and primary energy consumption. Also, using BEMS (an energy management system), optimizes the operation and energy consumption of the air conditioning, heat source and lighting, and maintains the environmental performance. In addition, with the environmental formation produced by the greenery in the walkway-type open area and the open space facing the canal, the greening within the site, and the rooftop greening, and with the spatial structure flexibility due to the no-core structure, a high building environmental performance of BEE=4.7 in CASBEE (Comprehensive Assessment System for Building Environmental Efficiency) was realized during the planning. In the future, with operation, we will continue to verify both the environmental quality and environmental load. *Programming method The method implemented by the company for discussing necessary requirements, and organizing problems and conditions.

Light courts invite natural light. Flexible, efficient office layout   Views through the stairwell Refreshing area next to light court

Client	Takenaka Corporation
Location	1-1-1 Shinsuna, Koto-ku, Tokyo
Design/Construction	Takenaka Corporation
Structure	Steel
Number of floors	7 fl. above ground
Building area	5,904m2
Total floor space	29,747m2