Passive housing neighbourhood in France waterproofed with Elevate RubberGard EPDM

Faced with global warming and increasingly demanding local regulations, the mindsets home owners are changing. They want to move into houses that respect the environment and are energy efficient without sacrificing architectural quality.

French architect Jean-Marc Proche and property developer Karine Maury sought to develop passive housing built from a polystyrene/concrete formwork system. Three years ago, they embarked on the design and marketing of an eco-responsible neighborhood project. In 2018, a first program named "La Petite Halle" was set up 50 km north of Paris, in Luzarches. Delivered at the beginning of 2020, it accommodates 16 apartments and two bungalows connected with 18 garages in wooden structure. Each house has a flat roof. "Choosing a cubic shape is most effective when you want a successful passive house. It also brings a contemporary dimension to the home," underlines Jean-Marc Porche.

To waterproof the houses’ flat roofs and garages, the architect wanted an EPDM roofing system, as it was completely consistent with the overall project. Holcim Building Envelope proposed their RubberGard EPDM solution, which has a Technical Appraisal in France (Avis Technique – Atec). With a life expectancy of over 50 years, the membrane contributes to reduce the site's overall carbon footprint. Free from harmful substances, it also allows to collect rainwater for watering the shared vegetable gardens. The membrane is also compatible with green roofs and photovoltaic systems.

The speed of the flame-free installation of RubberGard EPDM was also a key criterion. As the houses were designed using formwork blocks made of expanded polystyrene, cold installation was a guarantee of safety. In addition to 2,300 m² of RubberGard EPDM, Elevate’s V-Gard vapor control barrier and 120 mm thick RESISTA AK PIR (polyisocyanurate) insulation boards were used in this project.

Green roofs were installed on six of the houses, a real source of biodiversity. Tested in the laboratories of the German organization FLL and the KIWA BDA TESTING institute in the Netherlands, the RubberGard EPDM membrane is very resistant to root penetration. In combination with the RESISTA AK insulation boards, green roofs contribute to achieving energy efficiency. Temperature variations are limited in summer and winter, resulting on the owners saving on heating costs.

In addition, the roofs of four of the houses of this eco-responsible neighborhood were equipped with photovoltaic panels. These are connected to an intelligent electric radiator which analyzes the rhythm of life of the inhabitants and manages energy consumption accordingly. The solar panels were ballasted on top of the RubberGard EPDM membrane.

The waterproofing work was carried out by CHARI ETANCHÉITÉ, which is a Firestone Licensed Contractor. Between February and June 2019, 2,300 m² of RubberGard EPDM were fully adhered. "The winter period of 2019 was marked by strong winds, heavy rain and even snow. In spite of this, the installation took about twenty days, at the rate of one roof per day carried out by a crew of three roofers on average", explains Laurent Vyncke, Holcim Building Envelope Regional Sales Director.

The large 5.8 m wide RubberGard EPDM membrane panels used on this project made it possible to limit the number of joints, further speeding up installation and allowing both the roofing contractor and the building owner to save precious time.

Learn more about Elevate’s RubberGard EPDM roofing system and why it’s ideal for passive buildings.