This paper introduces a modified A* pathfinding algorithm that can be used in building Mechanical Electronic Plumbing (MEP) path design by revising nodes selection process and post-processing. The pathfinding algorithm is used when a computer calculates the optimal path in a given space by algorithmizing how humans intuitively calculate the optimal path. As construction technology is gradually advancing, buildings with large and complex internal structures are increasing, so there is a need to automatically optimize existing design methods that rely on human intuition for a more efficient design. In the case of building MEP design, it is time and money consuming to design paths since they are complexly arranged throughout the building, and designs are frequently changed in response to the nature of the construction industry, where construction errors are frequent. Therefore, an MEP path design optimization module, MEPAutoroute, was developed by implementing a modified A* pathfinding algorithm to solve these problems. Algorithm was applied to seven different exemplary structures with MEP equipment, and the results are analyzed to determine its efficiency.

As reconstruction and redevelopment accelerate, the generation of construction waste increases, and construction waste treatment technology is being developed accordingly, especially using artificial intelligence (AI). The majority of AI research projects fail as a consequence of poor learning data as opposed to the structure of the AI model. If data pre-processing and labeling, i.e., the processes prior to the training step, are not carried out with development purposes in mind, the desired AI model cannot be obtained. Therefore, in this study, the performance differences of the construction waste recognition model, after data pre-processing and labeling by individuals with different degrees of expertise, were analyzed with the goal of distinguishing construction waste accurately and increasing the recycling rate. According to the experimental results, it was shown that the mean average precision (mAP) of the AI model that trained on the dataset labeled by non-professionals was superior to that labeled by professionals, being 21.75 higher in the box and 26.47 in the mask, on average. This was because it was labeled using a similar method as the Microsoft Common Objects in Context (MS COCO) datasets used for You Only Look at Coefficients (YOLACT), despite them possessing different traits for construction waste. Construction waste is differentiated by texture and color; thus, we augmented the dataset by adding noise (texture) and changing the color to consider these traits. This resulted in a meaningful accuracy being achieved in 25 epochs—two fewer than the unreinforced dataset. In order to develop an AI model that recognizes construction waste, which is an atypical object, it is necessary to develop an explainable AI model, such as a reconstruction AI network, using the model’s feature map or by creating a dataset with weights added to the texture and color of the construction waste.