The subsurface investigation is the most important and preliminary part of any construction project, as it provides critical information regarding the soil strength parameters required for designing the foundation system. However, constraints like site inaccessibility, common in brownfield projects, can hinder the subsurface investigation at the required location. The present study illustrates the challenges encountered during the execution of piling works due to the inaccessibility of the project site in its initial phase of subsurface investigations. Consequently, subsurface investigation was performed in nearby areas for the estimation of pile capacities to carry out initial pile load tests. The installed test pile was 600 mm in diameter with a rock-socketing length of 2.5 times the pile diameter into the weathered rock. After performing initial pile load tests, the estimated safe capacity was revisited, and simultaneously, production piles were designed and installed at the site. During execution, production piles were terminated early as compared to the initial test pile length. While conducting routine vertical load tests, it was observed that the piles are not meeting the design capacity due to their early termination. The piles were terminated after achieving the targeted pile penetration ratio of 300. Therefore, a detailed geotechnical campaign was envisaged at the project site to understand the subsurface conditions of the site. The additional investigation revealed that there was significant spatial variability of rock surface from borehole to borehole. This led to further analysis of the foundations, followed by the installation of additional piles to support the superstructure.