Green Construction Materials: Light Permitting Concrete

One of the newest, most functional and revolutionary elements in green construction materials is light permitting concrete. Also known as translucent concrete and light transmitting concrete, this idea was originally developed by Hungarian architect Aron Losonczi in 2001.

Adding Light to Concrete

Translucent concrete is made by mixing optical fibers into the traditional concrete formula. The optical fiber strands constitute only 4 to 5 percent of the volume of the mixture, and the low percentage allows this green construction material to retain all the strength of conventional concrete.

Thickness of the optical fiber can vary, resulting in more or less light transmission, allowing a range of applications. Optical fibers are highly efficient, and regardless of the thickness of the concrete, lose no light conductivity. Colors can even be used, creating a variety of possible effects.


At first, the production was accomplished using individual fiber filaments, but production this way was expensive and time-consuming. More advanced processes use a fabric of the woven fibers rather than the individual filaments, and alternate layers of this fabric with concrete inserted into molds. This cast material can be cut into panels or blocks of varying thickness and can be polished to a high gloss finish, while semi-gloss is available as well. Even tiles are an option, and given the demand for new green construction materials, we will likely see even more permutations in the near future.


While there are limited examples of translucent concrete currently in use, some of the potential applications under consideration for implementation include:

  • Translucent concrete inserts on front doors of homes, allowing the resident to see when there is a person standing outside.
  • Translucent concrete walls on restaurants, clubs, and other establishments to reveal how many patrons are inside.
  • Ceilings of any large office building or commercial structure incorporating translucent concrete would reduce lighting costs during daylight hours.
  • Lane markers in roadways could incorporate various colors in the translucent concrete, allowing for dynamic adjustments when required by traffic fluctuations.
  • Sidewalks poured with translucent concrete could be made with lighting underneath, creating lit walkways which would enhance safety, and also encourage foot travel where previously avoided at night.
  • The use of translucent concrete in an outer wall of an indoor stairwell would provide illumination in a power outage, resulting in enhanced safety.
  • Speed bumps in parking lots and driveways could be illuminated from below, making them more visible and therefore more effective.
  • Subways using this material could be illuminated with daylight.

Look for other exciting applications of light permitting or translucent concrete to appear in everyday use as this technology grows.