Mori Building Co., Ltd.

Concept of the Development


The development concept for ARK Hills has the goal of creating a new business town for the 21st century in an era of increasing intellectual productivity, internationalization and greater use of information technology, in order to meet the new demand for a 24-hour business structure centered on Tokyo, London, and New York. ARK Hills is also adjacent to a cutting-edge commercial, cultural, and residential zone in Tokyo connecting Akasaka, Roppongi, Aoyama, and Azabu, and we created the complex as a place for multipurpose and diverse activities in the heart of the city, fusing business and these regional characteristics. Under the guidance of the government, we studied various ways to make the development multifunctional.
We conducted a series of physical studies and market researches and decided the operators who would actually run the complex and the combination of uses it would have, and as a result created the concept of a multipurpose city complex combining business, life, culture, information, and leisure, and offering large-scale, super-high-rise offices, apartment buildings in the heart of the city, a full-scale city hotel, a 2,000-seat concert hall, and a television studio.

The next major theme was the creation of a comfortable, relaxing environment while realizing the high level of functionality expected of a central city area. There was a need to maintain the unique environment of each facility while also building an environment that was encompassing enough to enable the buildings to coexist with each other. For this reason we incorporated natural environments to a large degree, including undulating landscaping and greenery and water.
This is also an era of technological innovation. We incorporated as many cutting-edge technologies as possible to create a comfortable environment. We conducted numerous studies of information technologies, which have developed particularly quickly, and in order to meet the needs of an age of pervasive information technology we decided to equip the complex with information structures, and to create a so-called intelligent city featuring intelligent buildings.
The fundamental concept of ARK Hills is the creation of "a total environment city," namely a business city that meet the needs of the current era of internationalization and greater use of information technology, a 24 hour multipurpose city complex, a city with a comfortable environment, and an intelligent city.

Facility Plan

In order to realize a high level of functionality, we combined 5.6ha into one urban zone and developed the twisting, narrow road that had existed before development (with a total area of 2,000m²) into two encircling roads with a width of 12m and 8m (and a total area of 7,000m²). We got rid of all of the former ward roads within the area and established the new encircling roads as the ward roads. The avenues of cherry trees on each side of the encircling roads have grown up and become famous. Every year when the cherry trees are in full bloom, many people come to enjoy them.

We have placed super-high-rise, spacious offices and hotels alongside the 40m wide Takanawa-Azabu expressway and positioned three residential buildings with six floors, twenty-one floors, and twenty-five floors on the south side of a hill where they get good sunlight. Between the residential buildings and the office building, we have created a plaza and there is a television studio facing the plaza and below it. On the north side of the residential building, there is a low-rise concert hall facing the plaza, as we take account of an environment for the existing residences adjacent to the north side of the complex. Our approach is the so-called “movement of capacity rights” through the “method of comprehensive design for apartment complex,” which increases the capacity of the commercial zone alongside the trunk road (the offices and the hotel) and keeps down the capacity of the cultural and residential zone on the south side.

The land on which the complex is situated is hilly and there is a difference of 20m in altitude within it, but we took advantage of that difference to build a plaza on the terraced fields. This three-dimensional plaza and the pedestrian walkways we created using pedestrian decks enabled us to make as spacious as 55% of the site into public space.
For comprehensive developments it is important to achieve a balance between consistency with the overall city district and the individuality of each building. We designed the complex so as to maintain the framework of the city and the identity of the town of ARK Hills and at the same time express the individuality of each building that arises from its functions.

With the changing times the needs, lives, and economic activities of people also change. Thus a transformation in cities is also needed. It is important to perceptively understand this need and act to renew cities so that they can continue to shine. It is difficult to change the framework of buildings, the hardware constituting cities, but it is not difficult to change the software with a view to diversifying the functions of cities. We have renewed ARK Hills many times since its completion.

In 1996 we responded to the diversified needs of office workers by establishing a conference facility, Academy Hills, fully equipped with the latest equipment, and then we transferred it to Roppongi Hills. We launched the ARK GARDENING CLUB, which also accepts residents from the surrounding area as members. In 1998 we carried out a large-scale renovation of the restaurants, including the joint-use facilities, to meet the needs of the changing food culture. We renovated ARK HILLS SPA to develop the living environment. We enhanced the gardens, etc. based on the concept of making greening, formerly a uniform approach, richer and more available to people. Aiming to improving the working environment of office workers, we also carried out across-the-board renovations including the creation of a floor containing office equipment, renewal of the design of the joint-use areas, strengthening of security, etc.
ARK Hills has played a guiding role in urban renewal and has become more mature over time. It will continue to evolve now more than ever, without ever stopping.

Architectural and Design Concept

The large ARK Hills site features multiple buildings with different uses. The fundamental shapes of the buildings differ depending on their uses. Some buildings can be super-high-rise and also have a large flat surface volume, some can be tall but must be slim, and others may require horizontal spread for the low-rise parts. If a good balance can be found between these shapes, then a high-density but appealing landscape and comfortable environment can be created.
A diverse world is expressed from the symbolic ARK Karajan Plaza, through the external spaces of each of these buildings, and to their internal spaces.
The ARK Mori Building was built to meet the needs of an era of internationalization and greater use of information technology and was Japan’s first intelligent building. At the time of completion many international financial institutions then new to Japan located their offices there and the ARK Mori Building was soon recognized as Tokyo’s premiere international finance center.
Furthermore, we have actively worked to add greenery to the building, including the rooftop, since the construction was completed, and the symbolic avenues of cherry trees and the seven ARK Gardens have evolved into a vital urban ecosystem, presenting seasonal landscapes in the heart of the city.

Architectural and Design Concept
Architectural and Design Concept

History of the Development

ARK Hills was the first large-scale multipurpose redevelopment project undertaken by Mori Building. Way back in 1967 Mori Building acquired its first land in this area and after the government had designed the site as suitable for redevelopment we actually spent nineteen years on the project. It is no exaggeration to say that the urban planning philosophy of Mori Building supported the enormous amount of time and energy we expended on the project.

  • Development Time Line
  • 1971:The Tokyo Metropolitan Government conducts a survey of the suitability of the site for redevelopment and designates the site as suitable
  • 1973:Minato Ward publishes the Basic Plan for Redevelopment
  • 1978:Akasaka-Roppongi Area Redevelopment Preparatory Association established
  • 1979:Urban plan decision announced
  • 1982:Establishment of the Akasaka-Roppongi Area Urban District Redevelopment Association approved
  • 1983Rights Conversion Plan approved
  • 1983:Construction starts
  • 1986:Construction completed