As part of urban rehabilitation of the ZAC Centre Sainte-Geneviève, a new neighborhood has seen the day in Nanterre, a unique place in France in terms of sustainable development. Urban density, social mix and innovative power in energy, those are the principles of spatial planning which have helped to transform this parcel of approx. 5 hectares into a real "eco-neighborhood".  Abdelmalek-Sayad, the school group which includes a recreation center in addition to a kindergarten and a primary school that can accommodate up to 400 children, is one of the sections of this urban planning project.

From its design to its use through the choice of materials, the wooden building imagined by the architect Nicolas Favet is a model of sustainable construction which displays a positive energy balance, thanks, among other things, to an effective wood-based fiber insulation made by HOMATHERM. The work of the architect Nicolas Favet pioneeres, and for two reasons: the wooden construction generates in a year more energy than it consumes, making it the first building to have positive energy balance of the municipality of Nanterre. A little more than half of the energy needed to produce hot water and heating comes from the recovery of the heat emanated from wastewater going into sewerage. The school and all the buildings in the neighborhood are supplied through underground pipes - an innovative heat distribution system, the first of this kind and of this size in France. Thanks to a photovoltaic system installed on its roof, the school group produces in a year more energy than it consumes, a surplus that is fed into the distribution network public.

Built in wood, insulated with wood

The timber frame with the outer shell serves as insulation; the construction firm Vaninetti has also focused on building a construction 100% ecological. The wood comes from forests that are certified sustainable within a radius of less than 400 kilometers, in order to maintain the CO2 emissions level as low as possible. The company has ensured in every detail the use of natural materials in order to allow this exemplary construction to display a positive energy balance - for this, an efficient insulation of the entire building shell was necessary. The insulation of exterior walls and ceiling of the building with HOMATHERM HDP-Q11 has emerged as an optimal solution from the ecological point of view, but not only: the high quality of the insulating panels made from wood fibers makes it possible to achieve energy savings due to good insulation values, but also to ensure optimal thermal protection thanks to a phase shift up to 14 hours.

An effective insulation for a good learning climate

The company Vaninetti has implemented in its workshops more than 80 per cent of wood fiber from the whole of the site. The wooden walls have been filled with rigid insulating panels HDP-Q11 standard 220 mm HOMATHERM. Delivered ready-to-assemble on the site, these elements were able to be placed quickly between the rafters of the wooden frame. The exterior walls have been reinforced from inside using an additional layer of HDP-Q11 standard 100 mm, thus offering a decoupling free of thermal bridges.

The three layers of rafters trim of the flat ceiling with HDP-Q11 standard ensures, with a total thickness of 32 centimeters of wood fibers, optimum protection against the summer heat and an effective insulation during the cold winter days. With a thermal conductivity of 0.040 W/ (MK) and a coefficient of insulation of 8.0 m 2 K/W, the insulating panels HOMATHERM allow all of the flat roof to  achieve exceptional coefficients in terms of thermal resistance. As the insulators HOMATHERM have a high absorbent capacity and are open to the diffusion of water vapor, they can perfectly store humidity of the ambient air temporarily and returned it in a targeted way. This helps to create a pleasant climate inside the classrooms and lounge areas throughout the year.