Structural Technology Group's "bioconcrete" is designed to retain moisture, nourishing the algae, lichen and mosses that grow on its surface while creating a solid fa?_ade for the structure. The "living concrete" system reduces atmospheric carbon dioxide levels, as the plant life absorbs CO2 while creating fresh oxygen.

landscapearchitect has reported on the debut of a range of new concrete products recently - from concrete made with biofuel waste to concrete that glows in the dark - but a product that premiered in Spain at the end of 2012 may be the most interesting yet.

Structural Technology Group, based at the Universitat Polit??cnica de Catalunya in Barcelona, Spain, has developed and patented "living concrete", a threefold breakthrough that allows the concrete to serves as a fa?_ade material, air filtration system and insulation layer.

The layers within the system begin with a waterproof membrane that rests at the base. The membrane creates a barrier that protects the housing structure from exterior elements, and serves as the foundation for the biological concrete. A special low-pH concrete mixture is applied on top of the membrane, with higher levels of magnesium phosphate, which creates a habitat appropriate for select plant life such as mosses, lichen, and algae.

Finally, a porous coating tops the design, harvesting available moisture from the surrounding environment and channeling it to the base membrane. The retained water and the biological organisms help to insulate the building, promoting a controlled climate for the building's occupants.

Unlike vertical gardens or other vegetated walls, there is no need for supplemental support systems that can add bulk to a building or limit its application to existing structures. Marginal maintenance keeps the structure beautiful year round.

The designers are developing variations of living concrete that foster particular types of plant life, helping builders control the appearance of the structure. The system allows the biological organisms growing on the surface to change and adapt to the seasons, and customizable exterior elements will permit more predictable control over energy savings.

Buildings in Mediterranean climates like Barcelona's will reap the benefits of the material first, as such environments provide the ideal combination of moisture and sunlight to help the organisms thrive. To date, concrete variations for drier and colder climates are not available, and researchers have not explained how the living concrete definitively deters the growth of unwanted biological organisms like mold, weeds, and unwanted forms of fungus.