Kong, Ruoyang

Zhang, Peng

English

University of Utah E Publications

ISUF 2020: CITIES IN THE TWENTY-FIRST CENTURY   ADAPTIVE REDEVELOPMENT IN THE REPLETION LAYOUT OF LEGACIES OF THE 20TH CENTURY IN CHINA: A CASE STUDY ON NANJING YIHE HISTORIC AREA Peng Zhang, Associate Professor of Architecture and Urban Planning, Tongji University, China Ruoyang Kong, Postgraduate of Architecture and Urban Planning, Tongji University, China ABSTRACT In the early 20th century, modern residential layout was introduced to China, but many of them gradually evolved into repletion layout in the years of public ownership. Nanjing Yihe historic area, used to be the residential area of the powerful class of the Republic of China, is a typical case. Based on the urban morphology research method of Conzen school, this paper summarizes the characteristics and evolution rules of different plan-elements in the historic area, especially different building types in the repletion phase. Comparing the early redeveloped district, the principle and method of morphological approach in adaptive redevelopment are elaborated to address the problem of lack of morphological analysis and control of historic setting. The application of this approach in the historic area is illustrated by an example of urban design, which preserve the outlines of plots and intersperses the historical scenes with new development, with new circulations and differentiate methods to deal with piecemeal buildings. Keywords: Nanjing Yihe historic area, repletion layout, adaptive redevelopment, plot INTRODUCTION  Nowadays built heritage protection is no longer limited to the protection of historic buildings, but also emphasizes the integrity of historic setting. Each historic building and its surrounding environment should be regarded as an interconnected unity. Meanwhile, in the protection and redevelopment, it is inevitable to involve the transformation of historic buildings’ functions, and the protection aim of built heritage has gone beyond the primary importance of preserving its historical value, expanding to revival of historic area. Confronting such a task raises two problems to be solved in the protection practice. First, how to analyze the urban form of the built heritage and understand which elements, except historic buildings, constitute the key characteristics of the historical environment; second, based on the interpretation of the urban form, how to deal with the historic setting, especially the no obviously important buildings in history, in order to balance the protection of historical and regional characteristics and solve economic and social problems. In order to solve these problems, this paper puts forward a combined framework from analysis to evaluation and guidance, and applies it to the analysis and design practice of Nanjing Yihe road historic area. BACKGROUND  Scarcity of sources with information at the scale of the individual plot is one challenge for the morphological study of Chinese cities, while the early 20th century witnessed the emergence of Chinese early modern urban areas(Shanghai, Guangzhou, Nanjing, etc.) designed by western engineers with rich cadastral atlas containing plot information remained, which is essential for 2 ISUF 2020 Cities in the Twenty-first Century research on urban form. These historical materials laid a foundation for the application of the theory of urban morphology employed by M.R.G. Conzen. Nanjing was designated as the capital of the Republic of China in 1927, and the capital plan was issued in 1929. American architects Henry Killam Murphy and Emest P. Goodrich were the consultants. Murphy presided over the plan, which was greatly influenced by the urban planning and design ideas of the United States. Yihe historic area belongs to the first rank residential area in the capital plan at that time. It is located in the north central area of Nanjing, with a total land area of 37.78ha, a building density of less than 20%, and a green area of 64.8%. It has a complete road system and landscape system, making the area the most stringent requirements for use and height control, the largest average plot and the best living environment among all the residential areas at that time. Since 1933, 287 mansions have been built. In 1949, the powerful class of the Republic of China retreated to Taiwan, and the blocks were taken over by the People's Republic of China. The area changed from the first morphological period to the second morphological period. The mansions were no longer only inhabited by the powerful class. One mansion can be allocated to many families to live together. With the change of users and the rapid increase of residential population, the area has entered a new round of construction period. At the same time, because of the public ownership of land, there is no need to carry out unified plan at the plot level, making buildings built first to deduce the plot red line. This construction method leads to the fragmentation of plot pattern and the diversification of property rights, which deeply affects the urban form. In 2006, Yihe historic area was declared protected. The area entered the third morphological period, and there was no new construction activities. 225 well preserved mansions of the Republic of China residence were listed for protection. At the same time, the area was divided into 12 districts, and the 12th District was renovated as pilot projects. In 2018, under the background of the revitalization plan, the urban design of the11th-1 District of the historic area was launched. The study on the urban form of Yihe historic area is the background of this urban design (Fig. 1). METHODOLOGY  The research progresses through three "how"- that is, how to analyze, how to evaluate and how to guide. In terms of analysis, based on the comparison of proposal plan, cadastral map and current plan, the evolution rules of street-system, plot pattern and building pattern are summarized, and the key factors influencing urban form are determined; In terms of evaluation, based on the analysis of the urban design plan of the 12th District and field survey, the effect of protection practice, especially the impact on urban form is evaluated; In terms of guidance, based on the analysis of the overall urban form characteristics of the historic area as well as the evaluation of transformed district, the principle and method of morphological Figure 1. Yihe Historic Area, the 12th District, the 11th- 1 District in the satellite aerial map 3 ISUF 2020 Cities in the Twenty-first Century approach in adaptive redevelopment are elaborated, and the application of this approach is illustrated by the example of urban design of the 11th-1 District. FINDINGS  Street-system and plot pattern (Fig. 2) Main roads and secondary roads proposed by the capital plan are differentiated clearly, forming regular blocks and evenly arranged plots. In the phase of construction, the division of plots was not completely based on the plan—there was a little merger and derivation. In addition, there was a reorganization of the plot, but these changes did not change the overall plot pattern. In the second morphological period, two ring roads in the middle of the area were occupied, two roads widened, and the vegetable market was cancelled at the east end. Yet these changes of street lines were not obvious, and the street-system generally remains stable. In contrast, the changes of the block pattern are very outstanding, the proportion of the merged and derived plots increased significantly, and the reorganized plots also changed the plot series greatly. Also, the vast majority of the plot boundaries have become quite uneven. Building pattern(Fig. 3)  During the first morphological period, the construction in a plot is composed of a mansion and a courtyard, so the mansions and plots correspond one by one. There are also three public buildings planned in the layout, while two are reserved at present. Most of the mansions were located at the Figure 2. Street-system and plot pattern analysis Figure 3. Building pattern analysis 4 ISUF 2020 Cities in the Twenty-first Century end of the plot, and a few were at the head of the plot. At that time, the architecture design of mansion did not include kitchen and utility room and just placed them in a long plane annex bungalow on the edge of the courtyard. In addition, entrance guards’ bungalows and garages were built along the streets in some courtyards. The conservation of these three types of buildings (all listed building heritage) shows us the old residence layout. There were two main building types in the second morphological period, reflecting the typical architecture growth characteristic of the repletive phase. We name the two repletive building types as R1 and R2. R1: Those were designed and constructed with regular shape. They are mainly unit residential buildings with Chinese characteristics, and some of them are schools, office buildings, hospitals and other types. The survey divided them into four categories to assess their impact on urban form: R1a: coexisting with historic mansions in the plot; R1b: located in the plot, but replacing historic mansions; R1c: coexisting with historic mansions, but changing the boundaries of plots, often occupying multiple plots; R1d: occupying multiple plots and replacing historic mansions. R2: Those are self-built, free-form piecemeal buildings. They are mainly of one to two-story strip-shaped bungalows, and its area is generally small compared with R1. As private courtyards become public courtyards, the area of courtyards is occupied by these bungalows. However, the construction of piecemeal buildings along the edge of the plot keeps courtyards as conserved public space. This makes them similar to the historic annex bungalows in the layout, the field survey found that the building forms are also similar. In the second morphological period when the planned plots no longer have the function of distinguishing, some piecemeal buildings intruded into other plots. Although such intrusion did not change the sequence of plots, the boundaries between plots were generally uneven. According to the general theory, the ownership of these buildings is diverse, and we should recognize them in different derivative plots with more subdivision. However, in the second morphological period, people tend to build first, then divide land, the so-called new plot has no boundary, and the original plot division still plays the leading role. It can be found that after the second morphological period, the Yihe historic area has formed the repletion layout, and different repletive buildings all have a profound impact on the urban form. Problems of protection practice in 2006 (Fig. 4) Through the above analysis, we find that the stability of the street-system and the preservation of part of the plot boundary provide the prerequisite for adaptive redevelopment, and the changes of the plot and building pattern have different degrees of correlation with the repletion buildings. To a certain extent, the repletion buildings can accommodate the space demand brought by the functional transformation, and also partially retain the morphological framework of the plot, which means that they are conducive to the protection of built heritage. On the basis of this realization, we reflect on the protection design and practice of the 12th District in 2006, and summarize the following problems: Figure 4. Plot borderlines and building pattern of the 12th District analysis 5 ISUF 2020 Cities in the Twenty-first Century Through the above analysis, we find that the stability of the street-system and the preservation of part of the plot boundary provide the prerequisite for adaptive redevelopment, and the changes of the plot and building pattern have different degrees of correlation with the repletion buildings. To a certain extent, the repletion buildings can accommodate the space demand brought by the functional transformation, and also partially retain the morphological framework of the plot, which means that they are conducive to the protection of built heritage. On the basis of this realization, we reflect on the protection design and practice of the 12th District in 2006, and summarize the following problems: -Protection only stays at the level of block, without concern on the value of the plot level. Finally, the courtyard walls between the series of plots were cleared, and the original courtyard form was dissolved, which destroyed the clarity of plot borderlines and spatial structure, as well as the preservation of historic value; -The one-to-one correspondence relationship between the mansion and the plot was not realized, as well as the cognition that the mansions are located at the end of the plot. People may believe that the building lines of the mansions were roughly parallel to the street –lines, so in the design, there were 9 new-built pseudo-old mansions (8 of them completed) which were contrary to the original plan; -The buildings in the repletive phase (maybe including some old annex bungalow) have been removed. But mansions preserved have small windows and doors, leading to poor interaction and weak support for new functions and inconvenient use, which is not conducive to the revival of historic setting. APPLICATION In the 11th-1 District, we found that the layout of the district has reached the climax phase, making the public space quite small. The repletion buildings in the area include three large-scale R1a and a large number of R2, which have quite little impact on the edge of the plot. In particular, R2 and the courtyard wall form the morphological framework of the plot, which provides the basis of protection. Therefore, we propose the following two guidelines in the urban design (Fig. 5). -Emphasize the role of plot borderline as morphological framework. Nowadays it is the general requirement of adaptive development to connect multiple courtyards to form larger scale outdoor activity space and promote commercial development. However, different from the past, the borderlines of the plots should be preserved as a micro morphological framework in the protection design of the 11th-1 District. Instead of destroying the borderlines of plots, we designed openings on the courtyard walls to connect the courtyards in the form of small Figure 5. Group diagrams of the urban design of the 11th-1 District 6 ISUF 2020 Cities in the Twenty-first Century squares. In this way, the parallel connection of courtyards will be transformed into series connection, contributing to new circulations with the outlines of plots preserved. -Integrate the annex bungalows and piecemeal buildings to fit the form frame. According to the investigation of the district, it is found that the single building form of the mansion is not conducive to the function transformation and the historic area revival, and it needs the assistance of other building forms. The repletive buildings, especially R2, is the first choice of building form because of its relation with plot outlines and annex bungalows both in terms of layout and form. Therefore, different from the practice in 2006 of retaining the mansions and demolishing other buildings in the district, the design of the 11th-1 District put equal emphasis on "retaining, transforming and demolishing", enriching the building forms and shaped various plot borderlines form by transforming the annex bungalows and piecemeal buildings built in the repletive phase, whose value was seriously underestimated in the past. CONCLUSIONS Article 9 of the code for Guidelines for the Protection of Cultural Relics in China explains that ‘Remove the worthless parts of past repairs; Return to the state of a certain historical period; The historic setting that can reflect the value of cultural relics should be restored’. This paper introduces the plan analysis method of Conzen School into the built heritage of China of the 20th century, analyzes the evolution characteristics of street-system, plot pattern and building pattern in ‘certain historical period’ , discuss whether the plot pattern, annex bungalows and repletion buildings are ‘worthless’ or not. In all, the study shows how to deal with ‘historic setting’ more sophisticated and efficient, forming a set of "analysis, evaluation, guidance" framework, with the 11th-1 District as a pilot. This kind of framework can be applied more widely in the historic areas of China which also have cadastral atlas containing plot information. REFERENCES Caniggia, G. and Maffei, G. C. (2001) Architectural composition and building typology: interpreting basic building (Alinea, Firenze).  Kropf, K. (2001) ‘Conceptions of change in the built environment’, Urban Morphology 5, 29-42. Scheer, B. C. (2010) The evolution of urban form: typology for planners and architects (American Planning Association, Chicago, IL). Todorovic, D. (2008) ‘Gestalt principles’, Scholarpedia (doi:10.4249/scholarpedia.5345) accessed 21 July 2019 Whitehand, J. W. R., Gu, K., Conzen, M. P. and Whitehand, S. M. (2014) ‘The typological process and the morphological period: a cross-cultural assessment’, Environment and Planning B: Planning and Design 41, 512-33.  Mengjiao Xue (2016) ‘Urban morphology of Yihe District in Nanjing during the Republic of China based on cadastral maps’, Nanjing University Shanshan Zhao (2017) ‘Study for planning and architecture of Yihe Road District’, Southeast University   7 ISUF 2020 Cities in the Twenty-first Century CORRESPONDING AUTHOR Peng Zhang, Associate Professor, College of Architecture and Urban Planning, Tongji University, China zhangpeng.patrick@qq.com 

Adaptive redevelopment in the repletion layout of legacies of the 20th Century in China: a case study on Nanjing Yihe historic area

https://epubs.utah.edu/index.php/ISUF2020/article/download/4261/3641

Adaptive redevelopment in the repletion layout of legacies of the 20th Century in China: a case study on Nanjing Yihe historic area

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