The old town is divided by the East, South, West, and North streets, forming a grid-like layout. Additionally, there are two horizontal streets and four alleys. Although the streets are short, the overall arrangement is compact and well-organized. Outside the town, the four main streets extend into Little East Street, Little South Street, Little West Street, Little North Street, and Word Street in the northwest corner, as well as Temple Street in the northeast corner.

Historically, due to the city walls, urn city, and bell and drum towers, only horse-drawn carriages and pedestrians were allowed to pass through. In recent years, with the development of tourism in the Tangjiahe National Nature Reserve and the construction of surrounding farmhouses, the area has become an important hub in the northern part of the Great Jiuzhai Circuit. The improved transportation and shifting consumer demands have led to an increasing number of visitors.

However, due to the lack of systematic planning and effective management, the roads have expanded haphazardly into the core of the old city. This has resulted in cramped streets and traffic congestion, which negatively impacts the scenic beauty of the old town and the lives of its residents. This design proposal focuses on addressing the issues faced by the east and west streets of Cross Street (Figure 2).

The buildings were surrounded by the ancient city walls and stretched inwards by the four gates on the periphery, and in modern times developed into the present form of an ancient town with a combination of commercial and residential buildings. The scale of the town began to expand in a disorderly manner. The first impression of the town is one of chaos, dilapidation and decay. In order to clarify the realistic design conditions of the design object, the existing buildings in the town were first investigated and sorted out (Table 1).

The existing dwellings in Qingxi do not possess distinctive architectural features, and their form and spatial arrangement fail to harmonize well with the surrounding environment and atmosphere. This can be attributed to the town’s age and the damage incurred from several significant earthquakes, as well as the lack of coordinated planning due to the autonomy of the villagers and excessive construction. As a result, the town is in a state of disarray. In order to revive the town’s historical charm and reignite its original spirit of history and culture, it is crucial to comprehend and organize its cultural elements.

Culture, as the embodiment of a community’s way of life, manifests itself first in material form and then extends to the spiritual realm. In the context of ancient towns, the culture is reflected in the physical expressions of traditional residential architecture (Wei, Cheng, Zhong, & Xiao, 2022) . The culture of a settlement community shapes its architectural culture, and, in turn, the architectural culture influences the settlement community (Ju, 2014) . Therefore, it is crucial to examine the chronological and contemporary perspectives in order to identify the cultural characteristics inherent in local residential architecture. By organizing and categorizing architectural elements, we can establish a comprehensive cultural framework for the residential architecture of northern Sichuan. This approach allows the integration of residential buildings within the broader spatial and temporal context of the town’s historical culture, which is shaped by the interaction of street spaces and the natural environment.

In terms of historical timeline, apart from a few sections of the old city wall in Qingxi Ancient Town that show evidence of renovation during the Song Dynasty, the existing traditional dwellings in the town primarily date back to the late Qing Dynasty and early Republican period, as determined from previous research. Therefore, the architectural style and dwellings in the town will be based on the architectural forms prevalent in northern Sichuan during this specific time period. Additionally, emphasis will be placed on incorporating a diverse range of architectural types to create a rich variety of spatial levels.

“The eaves are long, the walls are latticed, the cliff is covered with hanging feet, and the corridor is a running corridor.” (青瓦出檐长, 穿斗格子墙, 悬崖伸吊脚, 外挑跑马廊). This northern Sichuan folk proverb illustrates the distinctive architectural characteristics of the region (Zheng, 2018) . However, even though traditional northern Sichuan dwellings have their own unique language of form, it is important to understand how they are connected to the broader architectural context of Sichuan. In this regard, we can draw upon the theory of historical archetypes. This theory, developed by Swiss psychologist Carl Gustav Jung, suggests that individual consciousness is derived from the collective subconscious and evolves over time (Wang, et al., 2022; Hall & Nordby, 1999; Huang & Yang, 2023) . Applying this theory to architecture, we can view buildings as the material manifestation of the collective subconscious, representing the region’s architectural prototypes. This includes not only the physical aspects such as space, materials, components, and colors, but also the contextual and spiritual elements associated with the building.

Through our research on traditional houses in Qingxi Ancient Town and the surrounding area, we have summarized and concluded the general prototypical features of northern Sichuan houses, such as: the floating overhanging mountain style on the roofs; the “pierced latticework” on the roof frames; the “one light and two dark” spatial form; the choice of materials These rich architectural prototypes provide an objective basis for our next design, and also lay the foundation for the transformation of the residential houses in Qingxi Ancient Town (Figure 3, Figure 4).

At the level of implementing the prototype, the main means or approaches, based on realistic conditions, are as follows:

1) Facades: The modern building is restored and transformed, while retaining the original structure. The sloping roof is increased and the walls are finished,

translating the traditional dwelling’s decorative elements into the old building. The building facade emphasizes vertical division along the street, with a moderate increase in the number of pilaster walls and fire-blocking walls, maintaining a proportional relationship with the building. Considering the horizontal street surface, a differential transition needs to be taken into account while maintaining a unified style. This is achieved by systematically adding gables, ridges, hanging towers, and heavy eaves based on the overall relationship of the building facade.

2) Colour: The three main hues, red-brown, white and grey, are extracted from the prototype, interweaving together to present a simple, tranquil atmosphere and maintaining mutual harmony with the surrounding natural environment.

3) Materials: local materials are used to design the material of the building with whitewashed walls (白粉墙), tung wood (桐木) paving slabs, limestone and small green bricks. At the same time, in order to pursue economy, some new modern materials are used, such as inorganic polymer imitation wood as a substitute for solid wood and GRC to imitate stone carving. On this basis, in order to present the interest of the form, the design is optimised according to the pattern of the traditional residential façade, so that the building façade is as diverse and rich as possible in terms of heterogeneity and homogeneity.

4) On the architectural components: the main focus is on the addition of subordinate architectural decorations. For instance, the discordant doors were replaced with panel doors and waist doors were added. The hanging piers under the eaves were primarily adorned with pomegranate heads and longevity peach motifs in a round shape, as well as lotus flower carvings in a square shape. The plinths under the columns were predominantly decorated with pumpkin-shaped motifs on the ground floor, round motifs on the first floor, and eight-sided motifs on the base, featuring floral and bird embellishments on the surface. The window panes were selected mainly in the form of turtle-back brocade and step brocade. Additionally, wind and tiger windows were added as decorative elements according to the requirements.

5) Spatially: the ground floor of the existing building is topologically altered, topologically in the form of traditional residential space, and altered in the specific division and arrangement of space to make it more suitable for modern commercial needs, to facilitate future rental or self-use, and to create certain economic benefits for the indigenous people.

It is important to note that the restorative construction discussed in this article is in no way a reversal or an absolute copy of the prototype. Rather, the aim is to both “repair” and “build”. In accordance with the principle of proportionality, we have sorted the existing buildings in Qingxi into four classes, and then repaired, built or demolished them according to their classification (Table 2).

In order to enrich the visual and psychological spatial experience of the street tour, it is divided into primary node spaces. These spaces have a width of 5 - 8 metres and a height-to-width ratio of 0.8 - 1.6 metres on both sides of the buildings, aiming to create a comfortable activity space. Additionally, there are secondary node spaces with a width of 2.5 - 5 metres and a height-to-width ratio of 0.8 - 2.6 metres, providing pleasant spaces for people to rest and stay. Furthermore, transitional spaces with a width of 1 - 2.5 metres and a height-to-width ratio of over 2.5 metres are included to allow for quick passage, creating a temporal contrast between fast and slow, movement and stillness in relation to the main spaces. The individual buildings on the street are combined to form small square enclosures and intersections, which possess a strong sense of domain. They are designed based on the rhythmic relationship between the key and secondary elements, with an emphasis on controlling the contour line of the roof and ridge, highlighting the rhythm of the overall buildings against the background of the street’s skyline. By incorporating pagodas and corridors, the street space embodies

a relationship between reality and fiction. Lastly, there is a strong and weak relationship between the street architecture and the soft landscape, such as the design of the street’s water landscape and signage vignettes (Figure 5, Figure 6).