Keywords

1 Introduction

Bayu ancient town is a general name of the self-organized historical towns scattered in Chongqing and neighboring areas. It is the historical crystallization of the regional settlement and architectural form of Bayu. The settlement pattern of Bayu ancient town is a very special type in Chinese traditional architectural culture, which has been widely concerned by people in recent years [1]. In Bayu area, there is abundant rain, humid climate and large fluctuation of landform. Its traditional folk houses form characteristic Spaces such as sloping roof, inner patio, stilted building and falling and splintering floor, which constitute the traditional building form with rich symbols. The research on the protection of traditional residential buildings in Bayu ancient Town not only inherits the original ecological construction culture, but also effectively maintains the pattern and historical features of the ancient town, and maintains the integrity, authenticity and continuity of traditional residential buildings and settlements [2]. Given that the current research on modular protection design of traditional residential buildings in Bayu is not rich in theory, this article explores targeted modular protection design methods for Longtan Ancient Town in Chongqing, in order to provide experience for the protection of traditional residential buildings in Bayu Ancient Town.

2 Practical Problems and Basic Ideas of Traditional Residential Architecture

2.1 Analysis and Research of Practical Problems

Ordinary Dwellings were Badly Damaged

The traditional residential buildings in Bayu ancient Town are mostly brick and wood structures, most of them are aging and damaged. Some of the residential buildings of great conservation significance built in Ming and Qing Dynasties are seriously damaged, while a large number of newly repaired residential buildings are “square boxes pattern” with ceramic tile veneer, which is inharmonious with the overall architectural style of the ancient town. (Fig. 1, Fig. 2).

Fig. 1.
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Dilapidated traditional dwellings in Longtan Ancient Town of Chongqing

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Fig. 2.
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New tile - tiled dwellings, Figure source: Self-shooting

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The Historic Buildings were Badly Damaged

In Bayu ancient town, a large number of guild buildings, historical courtyards, ancestral temples, traditional shops and other historic buildings of typical significance have been seriously damaged or lost their functions, and many of them have even ceased to exist. Take Chongqing Longtan Ancient Town as an example, among the historical buildings of high cultural value “seven palaces and ten temples”, only the Longevity Palace of Jiangxi Guild hall is well preserved, but the other important architecture are no longer exist [3].

Insufficient Understanding of the Complexity of Conservation Efforts

In the conservation of traditional residential buildings in Bayu ancient Town, the problem of insufficient understanding of complexity still exists. First of all, the complexity analysis of the current situation of the building is not comprehensive enough. In general, there are a large number of traditional residential buildings in Bayu Ancient town, and the current situation is different. Some are well preserved, some are damaged and need to be renovated, and some are so dilapidated that it is difficult to guarantee basic safety [4]. In the protection work, to some extent the comprehensive understanding, combing and analysis of these traditional dwellings with great differences in current conditions are still lacking.

The second is the inadequate protection of the complexity of traditional architectural elements. The traditional dwellings in Bayu ancient town contain a large number of traditional components, the roof of a common residence in Longtan Ancient Town of Chongqing includes four important components: Roof tiles, eaves, overhanging eaves and roof ridge decoration. The rest components, such as door, window, beam, column, balcony, wall base, can be divided into a variety of different types. These traditional architectural elements have gone through historical precipitation and are of high value. If simplify them in the conservation work, the cultural connotation of the ancient town will be destroyed to a certain extent.

The third is lack of pertinence of the complexity of building types, the building types in Bayu ancient town are complex, including not only ordinary folk houses, but also special historical buildings such as all kinds of hall buildings, its use function is different from its historical value, and the protection content that needs to be expanded should not be the same. In the current protection work, some ordinary houses are renovated too complicated, while some special buildings with high cultural value are ignored [5].

2.2 The Basic Idea of Protection Design

The protection design of traditional residential buildings in Bayu ancient town is an important and complicated task. As mentioned above, there are various types of traditional buildings represented by classic dwellings in Bayu area, with different styles of old and new, the differences between ordinary folk houses and special houses such as courtyards and guilds are great, and the traditional architectural symbols are complicated, all of these make the protection and sustainable design of traditional dwellings more difficult to varying degrees. The key to solve practical problems is to find a feasible scientific method and design mode in work. Take the research and practice of protecting Longtan Ancient Town in Chongqing as an example, this paper puts forward the protection idea of “the data collation of current building elements, the modular renovation design of common residential types, and the key design of special building types” [6].

3 The Main Content of the Modular Protection Design Method of Traditional Residential Buildings

3.1 Current Building Element Data Collation

Sort Out Status Quo

Through field visits, the main residential houses within the survey scope can be evenly divided into several sections and numbered according to different orientations. For example, the houses on the east side of slate Street in Longtan Ancient Town are divided into E1 to EN, and the houses on the west side are divided into W1 to WN, etc., and the specific Numbers are compiled to facilitate grouping and research. Numbered the traditional residential houses in each block and collected basic data one by one. The basic information of traditional dwellings is sorted out from the aspects of architectural name, architectural form, space and number of floors, main functions, construction age, elevation drawing and preservation status of architectural elements, etc., and detailed data is recorded in the form of status questionnaire. In particular, the detailed description of the preservation status of multiple architectural elements is the core part of the status questionnaire [7].

Element Classification

It can be divided into several systems according to the actual situation of the main building elements of the present residence. The residential building elements of Longtan Ancient Town can be divided into six systems: roof system, enclosure system, door and window system, beam and column system, balcony system, and other systems. Each system can be subdivided into several subsystems, details as show in Table 1:

Table 1. List of architectural elements of current residential situation in Longtan Ancient Town
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In the status quo questionnaire, data sorting and recording can be carried out for each building along the street in a typical section according to the sequence of Numbers, so as to serve as the basis for protection and renovation work.

Modular Design Elements

Based on the questionnaire on the current situation of dwellings in Longtan Ancient Town, extracted the architectural elements with traditional features, well preserved status and suitable for construction. Number each element and design the dimension data, and then construct the modular model and describe the specific method (Table 2) and carry out targeted key research to seal the fire wall, Tujia stilted building and other special elements [8].

Table 2. List of Architectural Elements Design and Specific Practices (Part)
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3.2 Modular Remediation Design of Common Folk Dwellings

The trinity method of “face - line - point” can be adopted in the renovation design of ordinary folk houses in Longtan Ancient Town. (Fig. 3).

The Protection of “Surface”

The protection of “surface” is to renovate ordinary residential houses in the form of list. The element design work mentioned above is applied to the table. The main components of each building are listed in the table with specific renovation measures and corresponding renovation types of elements with corresponding Numbers, so as to achieve the goal of comprehensively covering the renovation work of ordinary residential buildings in the ancient town [9].

The Protection of “Line”

The protection of “line” is to carry out the streetscape renovation design. The key of section design corridor along the street facade, make the effect comparison before and after the transformation. In the renovation of the street style, the element design method is also used to replace or update the building structure part in the street view facade.

Fig. 3.
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Protection method diagrams of ordinary folk dwellings in “plane - line - point” Chart source: Self-drawing

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The Protection of “Point”

The protection of “point” refers to the transformation of individual dwellings. The typical residential houses are divided into several types, and combining element design to carry out the renovation. Each type can guide the reconstruction design of similar residential buildings. (Fig. 4) The selection principle of residential type includes repair and renovation (Take old repair old), renovation (change new into old) etc., combined with the renovation elements such as the number of floors and rooms (one to three floors/room), special elements (fire sealing wall, etc.), and other elements effects, summarize a variety of different types of residential reconstruction schemes. In addition, in the transformation of “point”, should follow the principle of “authenticity”, fully respect and retain the tangible and intangible cultural elements, and summarize the main points of renovation as follows:

The original wooden components of traditional dwellings should be preserved, and no complex components should be replaced.

The original transverse window, beam and eave structure of traditional folk dwellings should keep the original proportion and form when repairing. Other doors and Windows that need to be replaced should be kept consistent with their original appearance.

The grey brick wall and the traditional stone wall can be preserved, the poor brick wall surface can be transformed with wood, and the uncoordinated hollow brick wall and the white wall can be pasted with wood.

Three or four floors of new buildings within the protected area, the tile facade can be converted to wood. Facade can be added hanging eaves (not outward expansion), for the shutter door. The top floor of a new three-storey building that is too obtrusive can be knocked out.

New buildings with complete forms and coordinated features can be retained within the protected area [10].

Fig. 4.
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Design drawing of the renovation of ordinary residential buildings in Chongqing Longtan Ancient Town under the combination of “line-point” Chart source: Self-drawing

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4 Summary and Outlook

Combined with the case of Longtan ancient town, this paper puts forward the modular protection and design method of traditional residential buildings in Bayu ancient town. The protection of traditional dwellings in ancient town is a complex systematic project. Any problem in any link will greatly reduce the protection effect and even cause irreparable losses. In the specific work, it is necessary to further connect the protection method with the actual operation, such as paying attention to the construction drawing design, paying attention to the degree of completion and refinement of workmanship, and effectively organizing and following up the construction personnel, so as to ensure the real implementation of the design method. In short, the full consideration of the complexity of the overall process of protection is also an important issue that needs to be paid attention to and seriously faced in the future.