Les Trefles – ‘Passive School Building’

Year: 2014

Location: Anderlecht

Country: Belgium

Volume: 12000 m³ expanded clay 8-16 mm

Owner Builder: City of Anderlecht

Contractor: CFE Brabant

Designer: ARTER

Problem / Solution

The design for this school was a winning project in the city of Brussels’ call for ‘Example buildings 2012’. The school and gym both have progressive energetic- and environmental performances which meet the passive housing standards.


This project wants to be an example in terms of energetical performances but also wants to create energy efficiency awareness amongst children. This way, sustainability becomes a crucial part of this pedagogical project.

Why expanded clay?

The choice of building materials was based on Life Cycle Assessment, in which the ecological footprint is determined by the whole lifecycle. Since expanded clay is a 100% ecological product, it fitted perfectly into this project. Also, the design restricted the need for primair energy thanks to a thorough thermal insulation.