(A) study on the characteristics of planning within analyzing the 'physical settings' of exterior space in mixed-use development : the case of mixed-use development planning for urban regeneration in Tokyo

다국어 초록 (Multilingual Abstract)

The city, a space for individuals, is a complex of diverse elements where multiple ethnicities, cultures, and lifestyles are coalesced into one, presenting various tastes. Since it is an organically formed composite, a city constantly changes and evolves. In the process of the society transiting from primary to secondary or to tertiary industries, numerous cities evolve through there rise and fall. Cities that have decayed, reveal the problems of rapid hollowing out of the city as resident populations and commercial functions decline sharply and public institutions move out to the new towns or suburbs. Under these circumstances, one of the various measures suggested to revitalize the central area of cities that have decayed is urban regeneration.
In many cases, urban regeneration featured mixed-use development. In this vein, to enhance efficiency in the use of land and urban space in backward area, mixed-use development expands the scope of the urban space, horizontally and vertically, makes it into multi-levels, and mixes, converges, and overlaps various uses, systematically and reasonably. Also, as an efficient way to use space, mixed-use development seeks a means to invigorate the central area through mixed-use land and seeks to preserve the environment by curbing development in the suburbs. The integration and concentration of such urban functions, turn uneconomical functions (due to time and distance limits) into functions with characteristics. By minimizing unnecessary energy waste, it can reduce environmental pollution as well.
Mixed-use development helps ease traffic congestion through the use of job-housing proximity and also provides convenience in the use of various facilities. Also, it provides various exterior space for the city by reducing roads. Due to these merits, recent cases of urban regeneration show characteristics of high-rise, large-scale complexes, as conceptualized in mixed-use development. Notably, mixed-use development of mega-urban cities in Asia (e.g., Seoul, Shanghai, Hong Kong, Singapore, Taipei and Dubai), take the form of the high-rise concept, giving a concrete form to a compact city. In relation to immediate contacts, which are an inevitable result as buildings become super tall, not only is the ground that connects the city to facilities, and facilities to facilities, but also, the underground and the space above ground, have come to have three-dimensional exterior space. Under the circumstances, study on the planning characteristics of exterior space, in mixed-use development, is believed to be timely. Particularly, analysis on the cases of Tokyo, which have many similarities with Korea, will have important implications in exterior space planning that employs mixed-use development, which is carried out as a part of urban regeneration.
This study examines planning characteristics by analyzing the physical environment of the exterior space in the station area of Tokyo, which has undergone urban renewal as part of urban regeneration.
The exterior space in mixed-use development, which performs the function of urban exterior space, and has characteristics of medium space, which is between open private space and public space, is a major element that constitutes the city and determines its image. However, a study on planning elements of exterior space, in well-planned mixed-use development, can highlight a solution to the concerns that exterior space in mixed-use development is becoming more and more standardized and de-personalized.
The scope of this study can be divided into the theoretical and the spatial. The theoretical scope covers open public space and open private space, which are divided by the scope and classification method of urban exterior space. The study gives theoretical consideration to the changes and emergence of open private space caused by multiple problems. By doing so, it attempts to analyze and draw attributes of the physical environment that the exterior space in mixed-use development has, as it is considered more highly than general private open space.
The scope of the spatial study sets limits to the exterior space in the station area of Tokyo, whose construction was completed after 2002. The scope of the exterior space can be limited as follows: 1) space above ground, such as the streets in the space above ground, bridges, and roof gardens, 2) ground space, such as plazas, parks, and streets, and 3) underground space, such as the sunken and underground streets.
This study is based on space classification, which defines exterior space in mixed-use development. General types of exterior space consist of open space and street, while vertical types are categorized into space above ground, ground space, and underground space. Planning characteristics are studied through the analysis of physical settings , and within the spaces encompassed by those various types. As a method of study, a theoretical background was established through previous research papers and reference documents. Based on these references, both on- and off-line surveys were conducted on the targets (places) chosen for the study, and on-site research visits were carried out twice.
The framework divides exterior space into open space and street. As for open space, which acts as a medium, interconnectivity between space and space will mainly be analyzed. As for the street, which integrates walking lines, the connectivity of open space within mixed-use development will be emphasized and analyzed through the phase diagram of space. The physical environment seen in those two exterior spaces will be divided into hard and soft landscapes, as an effort to present a framework for the study.
Focuses on the specific targets ？ exterior space in Roppongi Hills, Tokyo Midtown, Shinagawa East District and the 1st district of Shidome ？ and are analyzed by the space classifications (open space and street). Then, the planning characteristics of the physical environment that are obtained through the analysis of each space unit ？ the air, ground, and underground ？ will be analyzed. Based on the comprehensive analysis results, this chapter will draw upon the planning characteristics that the exterior space of mixed-use development possesses.
On the basis of the results of this study, the following conclusions were made by analyzing the physical environment and planning characteristics of the exterior space in mixed-use development sites.
The characteristics of the exterior spaces in the four mixed-use development sites of Tokyo are summarized as follows:
First, the exterior space of mixed-use development sites can be divided into various spaces that include open spaces (squares and gardens) and streets. Open spaces, which are stationary spaces, are connected with the urban streets, gates of buildings, internal streets, and other open spaces through interconnectivity. The various types of spaces were arranged as follows: public squares, public gardens, ground squares, ground gardens, underground squares and underground gardens.
Second, the streets connect the open spaces in mixed-use development sites. The types of streets shown in the justified graph of mixed-use development sites were analyzed with reference to the floor plan, including public streets, ground streets, and bridges, and the results indicated that public streets are exclusively used for walking in mixed-use development sites.
The physical settings of the exterior spaces, of the four mixed-use development sites, in Tokyo were analyzed with the following results:
First, The results showed that the squares were symbols of mixed-use development sites, since they have spatial correlativity and are located at the centers, and served as the core spaces of various open spaces and building gates. Hence, squares are planned as a space where visitors to the mixed-use development sites can do various activities by locating environmental sculptures or stages. These sculptures or stages can be used as spaces for special events through hard landscaping work of the physical environment, rather than through soft landscaping. the gardens are located at the margins of mixed-use development sites in connection with urban streets. In order to draw citizens to the mixed-use development sites, soft landscaping, rather than hard landscaping, was performed and the gardens were opened to the public so that many citizens could enjoy the green spaces, naturally connecting with the interior streets of the mixed-use development sites.
Second, among the streets, public streets are the shortest movement lines across the mixed-use development sites, which are different from ground streets that are linked with gardens. They are connected to the destinations, as the flow of walking is continuously linked through bridges. As a result, no soft landscaping is planned in the physical environment of public streets, and even the hard landscaping is planned with only the essential elements, such as lighting and directional signs. However, public streets are recognized as a space to be planned as a design element much like a bridge. Due to the characteristics of public streets and bridges, they are planned at the location with good view, with consideration to the urban landscape.
Third, the exterior space of the mixed-use development sites in Tokyo, include the traditional elements of Japan, whether it is an open space or a street.
In conclusion, the exterior space of mixed-use development sites is constituted with various spaces, with each type of space having common factors in the correlativity and spatial status. The soft and hard landscaping, which constitute the physical environment, work in harmony with the various needs of the user, as they provide a good, active place that allows people to gather together. The analysis of the mixed-use development sites in Tokyo showed that they are places that have many amenity elements, as well as various physical settings that satisfy the needs of the user, which are different from that of the general exterior space