Moss growth in walling elements in buildings is a common cause of phenomena due to water accumulation and weathering conditions over a period. The presence of moss can lead to increased porosity, water penetration, and freeze-thaw deterioration, all of which can compromise the structural integrity of walling elements. Additionally, it speeds up the corrosion of steel reinforcement if any, and aids in the breakdown of the components. The study focuses on the visual inspection techniques used to evaluate the effects of moss development on walling units and structural integrity, especially brick, cement blocks, and cabook blocks. Researchers utilized visual inspections and photographic documentation to track and quantify moss covering over time, identifying growth levels, water ingress, and moisture-related issues. Image processing is a significant trend in Computer Science, enabling the identification and analysis of color differences using the Red-Green-Blue (RGB) ratio. The study uses an image processing approach and the K-Means Clustering Algorithm to determine the RGB ratio and identify the predominant color of each walling unit each week. The study reveals that moss maturity increases green (G) values, decreases red (R) values, and fluctuates blue (B) values due to environmental conditions. Cabook Blocks have the most extensive moss coverage, and Brick walls, and Cement Blocks have the least coverage. This could be extended to predict the age of moss and durability of the walling units by only taking an image of the moss-grown wall.