Section 21-1. Obtaining geotechnical expertise

Before excavation work under the foundation level is initiated for building structures, the excavation shall be assessed by a person with geotechnical expertise.
In connection with the excavation of trenches along the foot of a slope or in a slope with a gradient towards the side of the trench of more than 1:10, the plans for the excavation shall be assessed by an experienced person with sufficient local geotechnical knowledge.
Similarly, special precautions shall be taken in connection with excavation work where the ground in the immediate vicinity of the trench is exposed to additional loads, e.g. near storage sites, retaining walls etc.