Insulation material for the renovation of building L on the Etterbeek campus of VUB

17 februari 2021

Lola Lybeert, Lorenzo Toen en Stefano D’ercole, MA2 students in Chemical and Materials Engineering, conducted this research for the module 'Sustainability of Materials' (prof. dr. Hubert Rahier).

The L-building is just one of the iconic buildings present at the Vrije Universiteit Brussel, constructed in its brutalist style, giving it a typical raw character. Home to both the faculty of Physical Education and Physiotherapy, as to the sports facilities, it is a building many people see, enter, and use. It consists of several interconnected buildings. 

As part of the expansion of the Vrije Universiteit Brussel also the sports complex (building L) on the Etterbeek campus is up for renovation. In a proposition by MODULO KADERSTUDIO, the flow within the building would be optimized, a martial arts dojo would be built, and the sports hall would be insulated (1).

The building industry is constituting 40% of the total energy demand, approximately 44% of the total material use, and is responsible for the generation of over one-third of energyrelated greenhouse gases around the world, making it one of the less sustainable activities on the planet. The largest environmental impact is represented by energy consumption during the operational phase of buildings (2,3). Heat loss from buildings is mostly through outside walls and the roof, accounting for 35% and 25% respectively. Therefore, a high-performance insulating material is necessary in order to mitigate thermal losses throughout the building, thus increasing energy efficiency, and reducing the total energy consumption (2,3).

In order to choose an adequate insulating material, several factors have to be considered, such as thermal conductivity, cost, flammability, density, and the required R-value. For the latter, the legislation has to be controlled, as there are legal minimal values for buildings, walls, and roofs. Moreover, the policies regarding toxicity and all the legal procedures with respect to safety during installation are considered in this work.

After a first screening process, involving the most commonly used building insulation materials, glass wool emerged as one of the most fitted candidates for this renovation project due to its properties and its enhanced sustainability compared to the organic counterpart (PIR). As the world is undergoing an environmental revolution, the sustainability and more specifically the circularity of materials is highly important. Therefor the life cycle analysis (LCA) of glass wool is explained based on existing LCA. By making an inventory of the consumption of primary energy, materials, secondary raw materials, and water and the output and emissions of all different stages of the insulation life cycle, all positive and negative impacts of glass wool on its environment can be evaluated (4). The LCA consists of 4 essential steps: 1) defining the goals, scope, and functional unit, 2) making an inventory compilation, 3) assess the environmental impact, and finally 4) interpret these results (5). LCA’s give practical information on the environmental performance of products, which can be translated into the Environmental Product Declaration (EPD) (6).

Furthermore, a durability study on Expanded Polystyrene foam (EPS) has been studied according to the task of assessing the durability of a polymer or ceramic material. Firstly, the general properties of this material are presented briefly through an overview; afterwards, the durability is treated more thoroughly taking into account aspects such as resistance to chemical products, humid environments, and flammability. To end, the use of additives is explained in the scope of improving fire resistance.


Hubert Rahier


prof. dr. Hubert Rahier


VUB Campus


Vrije Universiteit Brussel