Assessing the impact and efficiency of cadastral modernisation on coordinate systems for orthophoto production is a complex yet vital task. Cadastral modernisation involves the updating and digitalising of land records, which is crucial for accurate orthophoto production. The coordinate system used in cadastral modernisation greatly influences the accuracy and efficiency of orthophoto production. Therefore, a comprehensive evaluation of this relationship is of great significance. In this context, using accurate coordinate systems is paramount for ensuring that orthophotos are mapped correctly onto the digital cadastral data. This study analysed the output of the coordinate system from orthophoto production that was mapped to the cadastral plan to become the 3D cadastral. Apart from that, the significant use of the integration of cadastral plan and orthophoto output for urban planning analysis. Currently, the preparation of site analysis and the development plan proposal by the urban planners in the department only utilise the output from the 2D cadastral plan and orthophoto plan without a clear methodology which is unpractical, unrealistic, and unresponsive to the environment. From these challenges, the study analyses the significant use of the orthophoto output for the urban planners to do the slope and contour analysis and volume analysis for the new development project and analyse how effectively the existing development complies with the town planning guidelines. The study is based on the results obtained from the UAV surveys conducted at Kampung Santubong, Kuching, Sarawak, by improving the survey and mapping practices through the SGeD20 coordinate system. The findings of this study have explored how the cadastral plan can be overlayed with 3D spatial data to facilitate the use of urban planning analysis.