Vol. 42 Autumn 2007

The two towers of the new Kajima Head Office Building were completed in August. Designed to foster collaboration, the building also incorporates the latest environmental and safety technologies. Head office functions, which until now were dispersed among the former head office and locations around Tokyo, have been consolidated in the new buildings, invigorating the organization and increasing operational efficiency.

Head Office Akasaka Annex

The new head office has a total floor space of 48,680 square meters (524,300 square feet), consisting of the new Kajima Head Office Building adjacent to the former head office building in Moto-akasaka, and the Kajima Akasaka Annex, bordering the KI Building in Akasaka. The new Kajima Head Office Building contains executive offices and corporate function divisions, while the Kajima Akasaka Annex and KI Building house technical divisions such as civil engineering and construction, design, development and engineering, as well as business divisions. Consolidating these divisions improves communication, and enhances the solidarity of Team Kajima beyond the confines of the organizational structure.

Promoting Collaboration Inside and Out of the Company The new head office combines various structures and organizations to promote collaboration. The key concepts for the project were flexibility (allowing for personnel transfers and other quick responses), sustainability (energy efficiency and other environmentally friendly features), and safety (protection from natural disasters and other hazards, as well as building security). The latest techniques unique to Kajima were actively utilized to ensure the highest level for each of these concepts. The building reflects the "Kajima style," a white exterior that reveals the structural elements, while the interior retains open, universal spaces without support pillars, with a module layout that allows for flexibility. The digitization of documents has reduced the space required for storage, allowing for a more efficiency use of space (8.3 square meters, or 89 square feet, per person).

Environmental Friendliness and Sustainability The "on-demand" intelligent lowenergy system "Eco Module" has been fully employed for the first time in an office building in Japan. The system uses sensors placed in defined modules throughout the office space that sense the presence of people as well as provide the optimal levels of air conditioning and light. It also makes full use of many new energy-saving technologies. Air supply vents equipped with sashes at the perimeter and interior stairwells utilized as vertical shafts provide natural ventilation during the day, while night purges cool the structure during the nighttime. Other features include a "Hybrid Thermal Storage System" combining ice thermal storage and building frame thermal storage functions, and "task/ ambient air conditioning" that makes a distinction between air conditioning for the entire space and for individual segments of it. The use of these technologies should reduce energy usage by around 30% compared to ordinary office buildings. Both of the head office buildings have been designated as "S rank," the highest level in the Comprehensive Assessment System for Building Environmental Efficiency (CASBEE) classification.

Functionality and Safety The two towers are equipped with an intelligent building system that integrates office automation equipment, and the building automation that controls their electricity, air conditioning and other facilities, by an IP network. The use of this fully IP-based "B·OA net system" provides safe and efficient environmental controls inside the buildings. It is also linked to Kajima's Real-time Disaster Mitigation System (RDMS), which incorporates a warning system immediately prior to an earthquake, equipment control functions and a means for instantly assessing the status of damage immediately following an earthquake. One of the major aims of this system, from the standpoint of the Business Continuity Plan (BCP), is to allow the head office to continue to function as a coordination center for construction companies following a disaster.

Overview of Buildings Kajima Head Office Building Site area: 2,337.41 square meters (25,170 square feet) Construction: Steel frame (portions concrete-filled steel tube, steel reinforced concrete, reinforced concrete) Scale: 14 stories above ground; 2 below ground Floor space: 15,163 square meters (163,300 square feet) Concept: The white exterior revealing the structural elements continues the clean-cut design typical of the "Kajima style." The concept of "compact and simple" runs throughout, exemplified by the lack of interior support pillars, and an efficient level construction that eliminates wasted space for corporate functions. Stairway floor marker Main conference room Third floor elevator hall The main entrance lobby Meeting room Evening view of the front entrance Second floor meeting area Fourteenth floor guest meeting room Workspaces Kajima Akasaka Annex Site area:* 5,066.92 square meters (54,600 square feet) Construction: Steel reinforced concrete (portions reinforced concrete) Scale: 15 stories above ground; 2 below ground Application: Office space (floors 1 to 9); residential units (floors 10 to 15) Floor space: 33,517 square meters (361,000 square feet) Concept: The Annex, since it adjoins the KI Building that mainly houses the Architectural design division, features thin pillars that blend with the exterior features. A shadow image has been used as the motif for the demolished annex building. *Excluding the portion with existing buildings Entrances to office and residential areas Workspaces Lounge View from the seventh floor View from an Annex residential unit Main entrance hallway Meeting room Underground entrance First floor dining hall ©Sadamu Saito. ©Kawasumi Architectural Photograph Office

Vol. 42 Autumn 2007 A Working Style for the New Age: The Two Towers of the New Kajima Head Office Are Completed Kajima around the World

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