Historical Cultural Layers and Sustainable Design Art Models for Architectural Engineering—Took Public Art Proposal for the Tainan Bus Station Construction Project as an Example

Abstract

The concept of “historic buildings” is cultural with evolutionary characteristics, mainly constructed in the category of historical culture and people’s living settlements. “Public art” is an artistic asset with aesthetic attributes in urban living spaces. It contains two connotations, “cultural landscape” and “cultural route”, which form an artistic symbol of urban architectural space at the same time. Along with the progress of an urban renewal plan, a local culture characterized the urban landscape, making architecture a tool used to convey cultural identity spatially. Two coexisting issues can be seen through the accumulated structure and long-term changes of historic buildings, a region’s appearance, and the content of the traditional architectural styles—cultural value preservation and modern urban renewal—which ferment and generate decision-making discussion of design subtly in every corner of a city. This study examines the extant literature and the design model of public art landscape setting to construct a design model that balances the cultural value of historic buildings, and the landscape of public art has been proposed as a result of this study.

1. Introduction

Little attention has been paid to small and tight spaces in urban systems, which are often fragmented and unorganized (e.g., small open spaces, green spaces, art deco building facades, and streetscapes); however, nowadays, they are formed by the influence of aesthetics and ecology and have gained a new dynamism driven by society and publicity. The dynamism is influenced by civic activity, referred to as a social ecosystem. This civic activity promotes sustainable design for public art, historical building renewal and demolition programs.

According to J. Becker (2004): “Public art is a multifaceted field of inquiry; it encompasses a wide variety of creative expressions in the public realm” [1].

Compared to current urban living spaces, the architectural styles left behind by his-tory show a strong and more profound sense of belonging. In other words, their distinctive features and historical traces exist as the “local power” and urban public art, which is a display of architectural culture layers. Implementing public art can connect the characteristics of local culture and show the characteristics of urban blocks.

The common sustainability features of public art include public accessibility, public realm placement, community participation, and public process (including public funding); however, these works can be permanent or temporary. M.J. Jacob (1992) said, “Public art brings art closer to daily life” [2]. In 1992 and 1998, the Taiwan R.O.C. government promulgated the “Culture and the Arts Reward and Promotion Act” [3] (Taiwan version of Percent-for-art Program) and “Regulations Governing the Installation of Public Artwork” [4]. Since then, public art has become an important cultural and artistic indicator for Taiwan’s urban public construction space. The design characteristic of sustainable public art determines how best to activate the images in the surroundings. The concept of “sustainability” arises in response to the perceived environmental deficiencies of a city. For example, A. Zittel’s public art: “Indy Island”, proposes issues of sustainability and sustainable living space that participants can actively participate in, which can be considered sustainable public art facing the challenge of public open space needs [5].

The “Cultural layer” refers to a layer of earth formed by the accumulation of human traces or remains of man’s activities in the past. The historical and cultural patterns can be examined with this concept of time evolution and stacking of the older and newer cultural layers. Furthermore, through the interpretation of modern architectural design and public art, traditional buildings’ value of historical and cultural sustainability can also be transmitted and preserved [6].

On the other hand, historical streets are the spatial pattern of historical buildings, which carry the historical information of the city and the memory of residents and a form of stacked expression of cultural layers. The designs of these stacked cultural layers in historical buildings are presented in the field of modern urban architecture through time, symbolizing the cultural assets of a living block. Making historic blocks follows the same nature as public art: “cultural landscape” [7], “cultural route” [8], and “intangible cultural heritage” [9]. These factors simultaneously form a design symbol of the image of a city.

The United Nations has promoted sustainable development programs in various economic, social, and ecological genres since the 1980s. In 2016, F. Ceschin proposed the “4 Innovation Levels” [10] of sustainable design, one of which is known as the “Spatio–Social innovation levels”; the context of this innovation is about the spatial and social conditions of human settlements and their communities. This can be addressed at different scales, from communities to cities. Therefore, through the forms of public art, the design style guided by the cultural layer of traditional buildings can be used as a wonderful method of sustainable urban design.

The most special requirement of the design characteristics for public art is the construction of interactivity. The setting environment of public art is the living space where citizens experience it with their five senses, and public art plays an important role in creating a community [1]; Figure 1 presents the statistical data of public art installations in Taiwan from 2018 to 2020 [11]. As shown, public art installations are mainly distributed in urban blocks with significant populations. This agglomeration phenomenon suggests that the number of urban construction and public art installation projects is proportional to the trend, and it also shows the coordinate phenomenon of public art for urban planning and artistic landscape. The form of public art has been transformed into a design concept in the space field, creative thinking that involves the historical building space, and an artistic landscape combined with the planning and resources of urban public building construction.

Public art refers to artwork installed in an open space. The primary considerations in evaluation have four design features: “Artistic expression in environmental space”, “Locality”, “Civilian interaction”, and “Feasibility of safety structure”. These four characteristics are related to the current reconstructed architectural styles in historic districts with the same essence and needs. Through evaluating traditional architectural design styles and using public art as a reconstruction method, the design elements of traditional buildings and the aesthetic needs of current urban planning can be obtained, which are the current selection focus of the urban public art landscape design and the decision-making for transforming traditional architectural space.

Artwork can be a feature of urban environmental education, especially when installed in the public domain [12]. Public art is an artistic asset with aesthetic attributes; it is the architectural space’s image facade, representing the fashionable beauty of the design at the time, which simultaneously forms an artistic symbol. Historic building facades represent a style of stacking with the time of the cultural layer; with its unique style and function, it simultaneously shows the value of historical culture and the beauty of the public art landscape’s design.

Therefore, this study analyzes the design elements of traditional historic buildings through the characteristics and proposes a design-involved method for the historical building space through public art. This study uses a design decision-making application model, matching sustainable design to provide artistic landscape planning of the future architectural environment.

In the 1970s, American cognitive psychologist J.J. Gibson proposed the “Environment affordance” theory, arguing that:

“Human beings must be able to perceive the space environment; the space environment it-self is perceived by people in the movement of the space environment, and the affordance of the environment is composed of elements provided by the environment to the users [13]. Architectural engineering design is a cultural activity of human society not only covering aesthetics but also exposing the inner essence and hierarchical structure of culture.”

Public art shows the artistic characteristics of modern architectural public space and the affordability of space environment design; it then creates the cultural place color of urban architecture.

Based on the above needs for the public space reconstruction of historical buildings and public art landscapes, the design evaluation involves quite a variety of levels. Comparative analysis needs to be carried out through an evaluation tool that can take into account the existing spatial elements and non-substantial design characteristics and can objectively analyze the characteristics of the overall elements. The research takes the historical building facade of Shennong Street, Tainan City, Taiwan, as the research object, through its facade design patterns, design elements, and the perception level of representative models, to conduct a questionnaire survey on the design characteristics of relevant research objects. In the end, the following results are proposed:

• An evaluation and extraction method for the design elements of historical buildings in the public environment space.
• A design model that shows the sustainable cultural value of modern buildings through the creation and design methods of public art.

2. Literature Review and Research Process

2.1. Literature Review

Historical streets are composed of residents living construction activities, which are different from the street traffic planning formulated by modern cities. The current development strategies of historic streets include preserving and maintaining historical build-ings, the development of artistic and cultural spaces, and public art combined with public works (such as art streets). Each issue is deeply challenging and developmental because of the difference in each city’s historical development and the needs of each area. Still, it is essential to preserve historic streets; the purpose of development and pursuit of a beautiful living environment is consistent. Shennong Street (Figure 2) is a historic street that remains the most complete architectural style and street form in all of Tainan’s historical districts since the Qing Dynasty [14]. During the Japanese colonial rule period, the “urban area correction” plan was carried out; most of the buildings on Shennong Street were rebuilt and adapted for residential use. The 1st and 2nd floors of the buildings contain rich facades from different periods that forms one of the main features of this historic district [15].

The architectural facade style of a historical street (Figure 3 and Figure 4) contains the life experience and beliefs of the residents and shows the overlapping characteristics of modern life culture and the economic pattern at the time. In this research, a case study was carried out through the design style of the traditional building facade. It used the facade’s design style as a reference to propose a design method for the co-construction plan of the historical building space and architectural art engineering.

2.2. Research, Investigation and Process

This research and investigation take the historical streets of Shennong Street as the scope. Through field interviews, document surveys, building facade drawings, and style models, Figure 5 summarizes the definition and classification of facade building types as the basis for the perceptual evaluation of facade building design styles.

A questionnaire survey was conducted on the facade design styles and components to obtain facade design styles data and historic buildings’ spatial planning and public art design styles. The focus of the investigation is as follows:

• Investigation of main design elements of street building facade:

A total of 47 buildings were on-site, and the field survey time was June 2017. The primary collection of facade styles includes the facade material, window design, and entrance design of the first floor (Floor A), and the facade material, window design, handrail design, and entrance design of the second floor (Floor B), as shown in Figure 6.

2.

Interview:

Residents were used as the interview objects and conducted in-depth interviews on the current usage of the street, including the problems of community construction, the impact on the usage of the space change, and the historical memory of the buildings. The questions were used to integrate traditional districts’ past and present lifestyles and the expectations for current and future use of the space.

3.

Questionnaire:

The main evaluation items of the questionnaire were obtained by inviting experts and scholars to conduct interviews and discussions through the aggregated classification and definition data. In this study, experts and scholars screened the items and compared the items of building facades of Floors A and B. The decision-makers selected each paired element with the Likert scale to obtain the pairwise comparison values for each item. The subjects of the questionnaire are experts and scholars with professional backgrounds in architecture and public art to gain the weight value of the design style features of the facade. The research process is shown in Figure 7.

2.3. Classification and Definition of Research Objects

The building facade styles are drawn based on the north and south side buildings (Figure 8). The facade design styles are classified and selected through the Delphic hierarchy process (hereinafter referred to as DHP).

In order to distinguish the design styles, techniques, and materials of the facades of historical buildings from Figure 8, they were compared by the DHP method to delete similar design styles. The results concluded that the following building facades are the most important design features, as shown in Figure 9.

• The Floor As’ facade design features:
  • Multi-format window style (No. 65).
  • Wooden partition-windowless style (No. 49).
  • 2:1 multi-grid wooden structure window style. (No. 53, 57, 59).
  • Open windows on both sides with a middle door and washed stone finish wall style (No. 61, 64, 66, 88, 90).
  • Long facade wooden door style (No. 70).
  • Open windows on both sides with wooden facade style (No. 72).
• The design features of the Floor Bs’ facade:
  • The facade design’s axis is divided into three equal parts vertical facade by vertical and horizontal.
  • 2F’s window and door correspond with 1F’s design.
  • The design lines of the balcony are mainly vertical lines, crossing lines, squares, and rhombus.

From Figure 9, the following design rules were concluded:

• Multi-format window.
• Open windows on both sides with a middle door.
• The facade design’s axis is divided into three equal parts vertical facade by vertical and horizontal.

These design rules form the overall architectural construction planning of Shennong Street; its unified architectural style suited the living and industrial model at that time. These design rules contain important design elements that can be used in future architectural projects and public art landscape planning.

3. Research Method

3.1. Research Method

Architectural projects and public art landscapes have the characteristics of modern urban space fashion and aesthetics. According to space requirements and shape design, different art forms and design forms are produced, and there is a visual evaluation and functional affordability hidden in the spatial aesthetics. This functional affordability makes the overall construction project have diverse characteristics in the interaction of environmental behavior and forms visual characteristics.

Although the above-mentioned methods have a clear theoretical context and high practicability, they cannot take into account the subjective factors of human qualitative thinking and those factors with high uncertainty; for example, when facing the evaluation of various arts, culture, and creative thinking on the decision-making of public art installations, proposing a simple objective evaluation and decision-making method can provide a result that is in line with the needs of people. Therefore, this article proposes a combination of the DHP and AHP that uses the eigenvalues comparison matrix to analyze and calculate the optimal design features.

This study uses AHP as the primary research method. It provides objective mathematics to address the inevitable subjectivity and personal preferences of individuals or groups of decisions, empowering models with group decision-making capabilities [19]. Furthermore, it can construct a set of pairwise comparison matrices for each element at the upper level to compare elements in the lower level [20].

Conversely, the DHP will be used to centralize and delete opinions to achieve the effectiveness of evaluation indicators. Due to the method contained in AHP, there are three advantages: (a) It will be more effective and simpler to use the DHP with the AHP(EM) to acquire the specific or abstract facade style of the historical building. (b) The analysis of the first and second items in the weight order can concentrate more on the decision-making focus of artworks. (c) Using the DHP for decision-making inspection of art-works can avoid unnecessary pairwise comparisons, which can evaluate the decision-making of setting projects more accurately.

This study examined the extant literature research data and survey analysis, then formed a structured questionnaire. The study then performed a DHP expert evaluation to obtain the classification design characteristics of each facade. AHP(EM) was used to perform a pairwise matrix comparison operation; the weights of each pair of indicators were obtained using MATLAB, a compiling software. A paired matrix comparison of each element was conducted, along with the consistency check and sorting.

The facade design style of historic buildings and public art attributes have a complex design structure, covering the needs of historical culture, urban function, and urban planning. There exist tangible structures, intangible space aesthetics and other factors; therefore, it is essential to evaluate decisions through a method that establishes decision-making principles that can have implications and simplifies the design problem. According to the data obtained from the above evaluation questionnaire, the higher the weight value (ω), the higher the evaluation degree.

Take the matrix diagram in Formula (1) as an example; through a 7 × 7 matrix, to obtain Lambda max (λ_max) and the value of CI/CR is ≤0.1, which means it is consistent. When the matrix converted into a ω matrix, the weight value of this item can be obtained.

$$CR=\frac{CI}{RI}CI=\frac{{\lambda }_{\max }-n}{n-1}$$

(1)

3.2. Result of Analysis on Design Evaluation

The building facade is the unity of architecture function, structure, and design aesthetics. It is composed of color, material, scale, proportion, direction, shape, and combination. This study processes perception-level evaluations based on aesthetic elements of the historic building facades, to obtain representative design styles. Through the overall analysis results, the weighted items of artistic features obtained by the weighted eigenvalue method are used to pair with the application method of the existing building facade styles. These can be used as design elements in the current historical street reconstruction, cultural management, and community construction and as an evaluation application method.

The weighted items and the current status of building facades are compared and tested by experts on the analysis and calculation results. After the examination, they all reached the evaluation consistency and obtained the following design evaluation rules for building facades. According to the top two weighted values, the representative styles are as follows (for exact weighted values please refers to Appendix A and Appendix B):

• The window design is mainly based on unity, geometry, order, and balance (Figure 10).
• Handrail design styles are the most diverse in patterns and materials. The design styles are mainly based on continuity, rhythm, symbols, proportion, and order (Figure 11).
• The design styles of the entrance are relatively unified, mainly based on proportional order, balance, and stability (Figure 12).

4. Sustainable Design Patterns for Architectural Engineering and Public Art Landscapes

According to the results of traditional architectural design elements (the public space needs, civilian interaction, and the aesthetic engineering concept), an innovative design plan was proposed and won the silver award in a competition of a public art installation project.

The research object in this article is based on the public art proposal: “OPEN—The Folder of Time” for the Tainan Bus Station public art project. Since the Tainan Bus Station public art project is a percent-for-art program and must achieve the requirements for the open competition, it must be related to the architectural design of the Tainan Bus Station itself.

The architects put historical factors and meanings into the architectural design. It carried the function of transportation just like Shennong Street, the most well-preserved historical district in Tainan, which was also used as an important transportation road in the early days (historical and cultural roles overlapped); therefore, by translating Shennong Street during the Qing Dynasty into “Street of Tainan” in buildings, the architects take this as the core concept of the architectural design of the Tainan Bus Station.

The public art proposal “OPEN—The Folder of Time”, its design and planning combine with the design concept of the Tainan Bus Station; the representative facade design styles are used as the design elements for public art installations, which deeply describe the geographical connotation, and historical context and continue the historical memory of the “cultural layer” of the installation location.

Tainan Bus Station is located upon the relics of the town office during the Qing Dynasty. In order to avoid deep excavation and damage to the historical relics that were preserved on-site, the design leans toward the shallow foundation and lightweight green building materials, recyclable steel structures and containers as the main structure. As a temporary, non-permanent building, the operation period is expected to be 10 to 15 years. After that, according to the committee of the Tainan Bus Station, it will be demolished for other uses, such as museums.

Therefore, in the public art installation plan, through the steel structure, the building facades are transformed into the structural order of the building space, which is formed by the facade steel structure like a container, performing the concept of a “cultural layer”, the time delay, and space division. At the same time, the core concept of this public artwork is consistent with the reuse plan of the Tainan Bus Station, which considered the possible direction of sustainable development in line with the reuse of the structure of the Tainan Bus Station shown as following Figure 13.

4.1. Fusion of Public Art and Architectural Engineering

The fusion of the public art planning and architectural engineering is completed by designing it with the most representative eight groups of facades of historical buildings as a unit (Figure 14). A theme of “OPEN—The Folder of Time” illustrates the significance of the historical architecture, overall cultural atmosphere, and the separated meaning by the cultural layer content of spatial stacking and time deposition on the construction base used.

“Overall” refers to the “historical building facade” and the corresponding setting location, “Tainan Bus Station” (Figure 15), as an overall of the same cultural layer. The separated overall can refer to the “individuality of different facades of the same historic district”, corresponding to “one station after another, each station has integrity; however, different transport vehicles have their individuality”.

4.2. Same Time but Different Individually

Different cultural layers have continuous characteristics in the process of linking history, with both time delay and spatial distinction; history as an event is the “Perfect tense” of the time. Past, present, and future are the three tenses identical in continuous time but different individually from the space point of view. Therefore, this study proposes the public artwork method that expresses the “is form and content” to present the art form in the cultural layer and the multi-layered meaning of diachronic time and synchronic space.

4.3. The Construct of Public Art Landscape and Architectural Engineering

4.3.1. Creation Interpretation

Since the 1990s, the design concept of public art has gone far beyond the simple form of sculpture and a monument sitting alone in the open square [22]. Therefore, this interpretation uses the form of public art to express the unique historical background and location conditions of the “Bus station” and “Street of Tainan” in multiple cultural layers. It also implies the distinguishable characteristics of time, which symbolizes the combination of the three temporal sequences of past, present, and future and the continuous nature of the cultural layer space in the overall architectural space. The location of public art shown as Figure 16.

4.3.2. Design Method

“Public art been increasingly advocated on the basis of contributions to urban regeneration since the 1980s. Most decision-makers argue that public art can help develop a sense of identity, develop the sense of place, promote citizens’ identity, address community needs, and social exclusion; has its educational value and the function of foster social change” [23].

Considering the historical background and location conditions of the multiple cultural layers, the representative building facade style (as Figure 17) is present in the way of public art through the following three features: (a) Takes the rhombus patterns that appear in large numbers on the facades of historical buildings as the design elements for the three-dimensional design. (b) With quadrilateral rhombus to interpret the bus station as the heart of urban traffic. (c) The overall meaning of the public art is to present the “ex-tending in all directions” functions of the bus station; this not only transforms the cultural layer design elements of historic buildings but also the historic value of the past is represented in the beautification of modern architectural engineering, which is the fusion of art and architectural engineering that re-deploys meaningful historical documents in the modern urban living space, showing the beneficial result of architectural beauty and cultural experience at the same time.

4.3.3. Color Scheme

One can integrate the color scheme of the building and analyze the cultural layer’s time, distance, and space at different nodes to distinguish the difference in hue, saturation, and vibrance. With this color scheme, the public art can also coincide with the architectural design of “Tainan Bus Station”, shown as Figure 18 and Figure 19.

5. Conclusions

The 19th-century Austrian architect C. Sitte analyzed the spatial characteristics of European cities from the late classical antiquity to the post-industrial revolution in his book “City Planning According to Artistic Principles” (Der Städtebaunach seinen kün-stlerschen Grundsätzen) (1889). He discovered that the urban space loved by residents was not those large-scale squares or palaces but those well-proportioned, well-interacted, and beautiful urban landscapes; he emphasizes that, with a design sense of free life, the coordination between buildings and the encompassed squares and streets are the elements to achieve the purpose of the aesthetic planning of a city [24]. He believes urban architecture is a comprehensive work of art that must be planned and constructed based on artistic principles. As for urban architecture, he believes that urban architecture is a comprehensive work of art that must be planned and constructed based on artistic principles. D. J. Curtis (2010) also argues that “the arts have an ability to communicate environmental information… and to normalize concern for the environment, taking it from the realm of ‘problem’ to the realm of general conversation or even entertainment” [25]. The public space of Shennong Street has the artistic characteristics of the public space mentioned. The facade of the historical building on Shennong Street is an arrangement of artistic images and the space between the building facades on both sides; the historical street buildings and the artistic features of the facades constitute the historical value of urban development.

Heritage buildings are a cultural concept with evolutionary characteristics, mainly constructed in the category of historic culture and people’s living settlements. The construction space of modern projects makes people’s living space and the buildings group a certain correlation and produces unique architectural forms and living needs. Public art is an artistic asset with aesthetic attributes in the architectural field and also forms an artistic symbol of urban architectural space. Through describing the boundaries of public artworks, combined artworks, urban architecture, and public spaces are formed into a structure with perceptual entities that residents have a common impression of, which itself becomes an “image” [26]. This means that the public art is a space that creates memory; relatively speaking, the appearance of the cultural layer of a region can be seen from these heritage buildings. In the process of research and practice conducted for this this study, the following discoveries have been made:

• Applying the design that retains the historical and cultural context of the heritage buildings to the current city is an important method to show the sustainable cultural value of modern buildings.
• A design model found the balance between the cultural value of historic buildings and public art.

As an implementation case, the purpose of this research is to propose a field of innovation and a direction for sustainable design. Make the preservation of historical buildings not limited to widely discussed issues and methods such as: the maintenance of historical sites, the preservation of cultural relics, spatial activation, reconstruction and reuse. For the public art proposal “OPEN—The Folder of Time”, its design and planning combine with the design concept of the Tainan Bus Station to translate history and culture into a sustainable design. By using “public art” as a medium, through the fusion of architectural engineering and art, history and culture are translated into a sustainable design art model. In the face of the rapid development of the city and the current state of continuous renewal and planning of modern urban architecture, through public art combined with sustainable design art solutions, whether it is preservation or construction planning, historical buildings and new construction will form an organic topology line of shaping the urban landscape and urban development.

Therefore, the result and contribution of this article is a practical solution that uses public art combined with cross-domain design, to open up another train of thought for the preservation, activation and reuse of traditional buildings. The authors sincerely hope that the opinions and discoveries in this study can become an innovative design and feasible method that benefit future urban architectural engineering, cultural preservation, and urban renewal projects.