Additional 2 levels were added underneath the existing ones between two pylons of the control tower having had been built according to drawings by UVATERV Ltd. in 1983. The construction operations had to be performed without disturbance to, or suspension of the object functioning.

Supporting frame of the floor slabs: EURO-profiles, spaced at 3 m seated in the pylon seats, located at a distance of 15.30 m, which had originally been provided for in the design. The steel fluted sheet placed across the beams comprises permanent formwork for the 5 cm thick concrete slab constructed atop it.

The framework of the proofed peripheral walls is built up of reinforced concrete panels, similarly to the original solution.

The construction built anew is a self-sufficient fire compartment.