Green Code Acoustic Slab®

The Green Code Acoustic Slab creates the possibility to optimize the room acoustics depending on specific requirements. According to the design variant, a weighted sound absorption coefficient (αw) of 0.4 can be achieved (with α 0.6 in the mid-low range).

The Green Code acoustic slab is an industrially prefabricated ceiling element with surface-equal, regularly arranged, rectangular, largely penetrating openings. Lattice girders, load-bearing longitudinal reinforcement, minimum transverse reinforcement, and if required shear reinforcement directly installed in the concrete slab. The underside boasts furthermore a metal formwork-smooth finish. A resonance body spanning one or more openings is positioned directly above the openings onsite before concreting. The resonance body is partially filled with an acoustic insulating material.

The bottom of the slab can be left with the visible opening slots or optionally filled with acoustic absorbers. After the installation of the elements on site, placement of additional reinforcement layers and casting of the onsite concrete, the result is an acoustically optimized, monolithic ceiling system.

The ceiling underside can be left with the visible opening slots as desired. Cosmetic finishing work as well as special precautions during installation and concreting need to be observed. Alternatively, the underside can be treated with a pigmented finish on site. To achieve a customary white ceiling underside, the technically proven Green Code acoustic finish can be applied.

The Green Code Acoustic Slabs can either be designed and produced in two different variants:

Green Code Box: The frame of the GC Box is already fitted directly into the concrete element at the factory. The desired resonance body is then connected to the frame elements on site. The on-site resonance body is equipped with mineral insulation wool, including an air-permeable fiber protection fleece. In addition, there is an air chamber above it - depending on the size of the resonance body.


The Green Code Acoustic Slab is also available as a Green Code Acoustic Climatic Slab. A combination of Green Code Acoustic Slab and Green Code Climatic Slab.


  • optimized room acoustics for any room concept
  • sound absorbers fully integrated into the ceiling
  • no significant impairment of the cooling and heating function in the ceiling
  • can be aesthetically integrated into the design of the room

Technical specifications

  • non-flammable, A1
  • Achievable absorption coefficient (αw)  equals  0.4 (0.6 at the mid-low range).
  • Metal formwork smooth, 70-80 mm thick concrete slab