Historical Architectural Space Design Elements of the Application Activation Decision–Taking the Building Facade on Shennong Street in Tainan as a Case Study

Taking the building facade on Shennong Street in Tainan as a case study, this study assesses the design decision on its pattern. The research methods include the Delphi method, the analytic hierarchy process (AHP)-eigenvector method (EM), and the Delphi hierarchy process (DHP). A total of 39 buildings (those which had been reconstructed or demolished were removed) were taken as the research cases. According to the analysis and evaluation of the selected facade patterns, the research method has the following important application benefits for the decision on and application of the design element of historic architectural space: (1) the AHP (EM) is simpler and more effective in obtaining the design elements of historic buildings; (2) the analysis of the top 2 items in the comparison of AHP (EM) weights can place more emphasis on the focuses in decision-making; (3) the design features obtained with the AHP (EM) and the application tested by the DHP can lead to a more accurate evaluation of the design elements of the subjects. With the facades of the historic buildings on Shennong Street in Tainan City as the subjects, this study explores the current situation of the facades and adopts a classified definition and model combination perception test. With the AHP as the method evidence, it uses the AHP (EM) to obtain the pattern design elements, so as to put forward a design evaluation and application method that pays equal attention to the current situation and the elements of historic buildings.