Multifunctional roofs in a neighborhood of passive buildings

How do you imagine the residential neighborhood of the future? Design criteria aside, part of your answer is probably: it should be environmentally friendly. For La Petite Halle, a neighborhood of passive buildings near Luzarches, France, the architect achieved energetic independence of buildings and efficient management of renewable resources by making the most of flat rooftop surfaces.


Luzarches, France

Project completion


Designed by


Project type

new build

Building type


Roof surface

ca. 2,300 m²

Roofing membrane

Firestone RubberGard EPDM 1.1 mm and 1.5 mm

There are many ways of activating the fifth façade: from green and blue roofs to solar panels, a roof lends itself to a wide variety of sustainable solutions. Jean-Marc Porche, the architect behind La Petite Halle, implemented all of them for maximum ecological efficiency. Thanks to its characteristics, EPDM covers all of these needs. Moreover, since the membrane itself remains uninfluenced by external conditions, has a service life of over 50 years and can be reused or recycled, it significantly contributes to the overall carbon neutrality of the buildings.


In a conversation with Jean-Marc Porche, we broke down three key functions of the roofs at La Petite Halle. Green roofs regulate the temperature of the building and provide a habitat for insects and birds. Photovoltaic panels are connected to smart electric heaters that analyze the way residents live and manage the consumption accordingly. Rainwater-collecting functionalities provide water for plants in a community gardening area. View the gallery and read more about the designing and building process of this eco-friendly neighborhood.


Extensive green roof system/ solar panels


Firestone RubberGard EPDM roofing membrane


Firestone RESISTA AK insulation


Firestone V-Gard vapor control membrane


Expanded polystyrene/concrete roof deck

There is a lot to
discover about EPDM

EPDM is the most future-proof roofing solution when it comes to sustainabilityperformance and design freedom. Learn more about the role it played within this project and many others by discovering its benefits.

How did EPDM elevate this project?

Green Roofs

Green roofs cool down and insulate. Reduce noise. Create habitats for birds and insects. All great features. However, it’s only made to last when it’s designed carefully and installed on the non-toxic root-and water resistant EPDM membrane.


The UV resistance of EPDM is the highest among all available roofing solutions. It lasts longer than the solar panels, which allows to create sustainable, low-maintenance solar roofs that function for many decades.

The future of roofs is green

Roofs represent about 20–25% of the total urban surface area. What is particularly visible on satellite photos is that we are not making the most of our roofs yet: more often than not, they stay empty. At the same time, as cities continue to grow and expand, becoming warmer and noisier in the process, roofs are expected to go beyond their primary function of ensuring watertightness. More than just “covers” on top of buildings, they need to contribute to their energetic efficiency, sustainability and overall reduction of the environmental impact. Green roofs are among the best solutions that address all these needs.