Eco-quartier de Pré-nouvel / Seyssins / Isère

Transitional landscaping

Lot C2 is the first stage of the development of the Pré Nouvel eco-neighbourhood, located in the town of Seyssins on the outskirts of Grenoble. The fourth and most recent neighbourhood to be built, it is intended to provide 500 housing units on a 6-hectare estate.
In the magnificent landscape of the Vercors regional park, between the banks of the Drac and at the foot of the Moucherotte, the project stakeholders, in collaboration with the urban planner Jean-Pierre Pranlas-Descours and the landscape architect Catherine Mosbach, set themselves ambitious goals in terms of environmental quality and the social mix in this neighbourhood, with its garden city feel. 
With a programme split into 47 affordable housing units for Vinci Immobilier, and 18 social housing units for Grenoble Habitat, the Tectoniques architectural firm sees this hybrid form of housing as a new conception of how to build towns and neighbourhoods in natural settings, to imagine more friendly, more cooperative towns, which they believe is their ecological and civic responsibility.

Living in parkland

The stated aim of lot C2, later named “Seyssins Heights”, was to build dense blocks within the parkland setting. Its implicit role was to set the tone for future urban planning by integrating subtly and graciously into the sumptuous mountain landscape.
This dense and compact project (4,800 m2 built on a 5,000 m2 plot of land) is designed around an open, permeable structure which lets the surrounding landscape in through a series of gaps and framed views. Nature permeates into the block through the graduated spaces, from the most public to the most private, preserving the residents’ peace and privacy. The buildings are laid out around a communal garden which opens out onto the Comboire forest to the south-east. There are no fences, forming an open island and allowing free movement between Seyssins and the parkland.
The significant height difference (7 metres) between the north and south sides has been put to good use. The housing units, divided into small, staggered blocks, set into the slope, break up the mass of the building as a whole, creating an overall impression that resembles a collection of individual houses, rather than collective housing. 
For reasons relating to energy consumption the apartments are accessed directly from the outside, allowing the creation of intermediate spaces between the natural surroundings, and the public and private spaces. Walkways, alleyways, passages, internal streets and other systems all make the most of the remarkable setting. The communal areas are linked via these distribution and circulation systems: a shared bike / pushchair storage facility in each stairwell, distribution and metering shafts, a boiler room, letterboxes, bins with recycling and composting facilities. 

Two projects, one architecture

The architecture is homogeneous across both projects, for both respective clients, making no distinction between the social housing and the affordable housing.  In terms of image and use, the “townhouse” feel predominates over and above that of collective housing; and is better suited to the surrounding landscape.  
The social housing forms the northern boundary, the affordable housing occupies the double bar to the west and south.
This hybrid form of housing offers an urban structure adapted to the garden-town setting, the required social mix, and the role this first phase of development is intended to play as a social mediator. On the ground floor, the housing is on one level and opens out onto the gardens to the south. On the higher floors, the apartments are on two levels with well-exposed terraces. The buildings are 10 metres high with a maximum of three levels. 

Simple, comfortable housing

The layouts of the apartments are simple and ready to be developed. All apartments are dual aspect – north/south – with the living room and kitchen on the south side of the building, and the bedrooms to the north. The plans are compact with no corridors and integrated storage. The limited depth of the buildings means there is plenty of natural light throughout the living space, even in the bathrooms.
The apartments are accessed via exterior walkways. Sheltered and comfortably sized, they also contain shared storage facilities and communal spaces.

A domestic scale

The rural setting and surrounding landscape, along with the new neighbourhood’s goals in terms of environmental responsibility, and the programme developed around a hybrid form of housing all argue in favour of a small-scale solution. This helps to mitigate the collective whole by breaking down the architectural volume into housing “blocks”, groups of houses, juxtaposed and piled up. 
In this way, each apartment and its accesses (walkways on the facades or stairwells) are easily identified. This landscaped urban space welcomes residents with an open, friendly feel.

Sustainable construction

As well as aiming to control the buildings’ energy consumption, various decisions were made regarding the construction which contribute to the final architectural output. Firstly, the decision to use limited materials where they are most effective: wood for the outside envelopes, concrete structure for the floors and partition walls, and a mixed metal-wood structures for the supporting framework, balconies, and staircases.
The preferred use of wood and prefabrication for the wooden framework walls, as well as for the metal and wood balconies, are a common feature of the firm’s work. The exterior cladding is composed of kiln-dried wood to limit the weathering effect, or cement boards. All the exterior features are independent of the building and supported by a light metal framework.
The two projects were built in parallel, with two separate calls for tenders which meant there were often numerous contractors working on-site (up to 40 contractors) which considerably complicated the project. The deadlines were also extremely short: 18 months for Vinci Immobilier and 13 months for Grenoble Habitat.

Lot C2 Eco-district of Pré-Nouvel / Seyssins
18 social housing units
47 housing units in accession

Project owners
Grenoble Habitat
Vinci Real Estate Residential

Total SDP: 4,795 m2
Cost of works : 6,75 M € excluding tax.

Architectural representatives: Tectoniques Architects
Economist: Engineering tectoniques
TCE Engineers: Egis Bâtiments
BE Environment :Tectoniques Engineers
BE Control: Veritas
SPS Coordination: Veritas

date of construction 2017
Photographers : Tectoniques (Royalty free photos)

Main products

Mixed wood – concrete – metal structure
Woods used: Douglas fir certified Bois des Alpes
Cladding: Equitone / Tectiva panels certified NF FDES-PEP on MOB
Insulating: Homatherm Insulation made of semi-rigid cellulose wadding and Rockwool rock wool
Occultations: Griesser BSO
Collective heating : Gaz Vaillant
DHW production by solar collectors + Atlantic DHW tanks
Sanitary equipment: Hans Grohe certified NF FDES-PEP
Electrical equipment: Schneider Electric certified NF FDES-PEP

Main companies

General contracting: BP Construction
Facades and balconies: SDCC
Joinery and Occupancies : White Joinery
HVAC / Plumbing: Sanybat
Electricity: Cofema
Earthworks, VRD : Converso