a. The minimum concrete strength class shall be grade C25/30 for landed residential developments and C32/40 for non-landed residential developments. Concrete used in HS/NS structures (including hollow core and joints), as well as concrete used for structures within shelter setback distance, should be of normal concrete density (2400kg/m³) and consists of 20mm nominal maximum size coarse aggregate.

b. The use of pre-stressed concrete for the HS tower, and the transfer structure and its supporting walls and columns is not permitted.

The steel reinforcement of concrete shall be welded steel fabric mesh and hot rolled steel bars. The minimum yield strength for the main reinforcements and shear links in the structural elements forming the HS or NS shall be 500 N/mm², and of ductility class B or better.