Under the umbrella of sustainable construction, a term is growing popular – “biological concrete,” which has impressive environmental, thermal and decorative advantages in terms of green facades’ construction.

This material is presented as a new concept of “vertical garden,” with relevant advantages compared to traditional systems, which usually require supports and supporting structures, containers, or containers for plant elements and an organic substrate that allows the growth of the same.

On the contrary, in the “biological concrete” facades, the organisms would grow directly on the concrete’s surface, which facilitates its installation and maintenance, making it suitable for both new construction and rehabilitation.

It consists of a system made up of three layers: the support layer, made up of conventional cement concrete; the waterproofing layer, which will protect the former from moisture and possible leaks; and the bio-layer, formed by biological concrete, a cement concrete rich in magnesium phosphate, which allows reducing its pH to the levels required for the proliferation of microorganisms (fungi, mosses, and lichens). ), between 6.5 and 7, together with a relative humidity of around 60%.

“Among the advantages of this new material, we can highlight its contribution to reducing pollution, since the types of mosses and lichens used absorb CO2 and transform it into O2, thus contributing to environmental quality improvement,” a key insight by the founder of and CEO of Royal White Cement company, Marcel Fadi.

“Biological concrete can also capture solar radiation, which allows regulating thermal conductivity, improving the building’s vertical envelope’s insulation.

“And finally, we must highlight the aesthetic value added to the façade, which will present a variation in its tones with a seasonal nature, going from greenish in winter, a time when mosses and fungi will increase, to other, typical of the drying of the same in the dry season,” shares Fadi.

Various studies reveal that only the shade they generate or the trees’ perspiration can lower the temperature by up to 9 degrees. Fighting the so-called ‘heat island’ effect is challenging, but it can be relatively more comfortable when construction helps. In this sense, biological concrete has a lot to say.

There are not few facades throughout the world that have vertical vegetation. Until now, the way to obtain a green facade had two paths: let it grow from the ground and use the building itself as a support or install a system to do the same. In recent years, this repertoire of ideas has incorporated biological concrete, patented by a team of researchers from the Structural Technology Group of the Polytechnic University of Catalonia (UPC).

What’s so special about it? That it can make “naturally pigmented organisms” grow as explained by its creators. An advance that has its importance, right at a time in history in which green materials are called to be more protagonists than ever. The advantages of betting on green concrete go, from the reduction in temperature that we have already mentioned, to the always positive absorption of CO2. Mosses, algae, or lichens have the power to capture and absorb not only CO2 but also the nitrogen present in the environment.

Examples of green facades there are many in the world. They can be an example of these impressive buildings or pioneering facade of a shopping center in Valladolid, which – for the moment- is honored to be the first across the country. However, biological concrete intends to change the current construction system and bet on ‘getting rid’ of the complex load-bearing structures necessary for the installation of indirect plants.