If hard rock is present, when is it usually better to drill the hole?

Drilling a hole before the building is erected is typically the preferable choice when hard rock is present for several reasons. Firstly, it allows for easier access to the work site while the surrounding area is still clear, without the constraints and obstacles that can arise from an existing structure. Doing the drilling before construction begins also ensures that the foundation work can be completed in a timely manner, as drilling through hard rock can be time-consuming and labor-intensive.

Additionally, addressing any issues with rock formations before the building is up ensures that there are no unexpected complications that could delay construction timelines or lead to additional costs. This proactive approach allows for any necessary adjustments to be made early in the process, ultimately leading to a smoother construction phase.