Les Marbriers II – Color

Situation

The aim was to create mainly low-cost housing, some with care for the elderly, and some as condominiums. Common outdoor facilities, in line with the provisions of the neighborhood plan, have been set up for all these homes. Within this framework, the Fondation HBM Camille Martin was the contracting authority for an important element of the complex, a building in two symmetrical parts served by a common entrance.

Techniques

The HPE label (high energy performance standard) guarantees the energy efficiency of the building, which is equipped with single-flow ventilation in the apartments and double-flow ventilation on the first floor for the offices and shops to be fitted out. Photovoltaic panels generate electricity, and heating is provided jointly by the district heating network from the Cheneviers plant and a heat pump.

Concept

The building houses 80 apartments. The layout of five apartments per floor, articulated around a single staircase, offers generous distribution space, complemented by a large void of natural light. Generally speaking, the small apartments have a single orientation, the medium-sized apartments are in the corners, and the large apartments are all through-planning. All apartments have large bay windows, and the larger units have loggias. The first floor is semi-buried.

It houses cellars and equipment rooms, as well as two large bicycle storage areas, accessible directly from the arcades.

The single entrance hall gives access to the two distribution cages, as well as to the laundry room and common room. These two communal areas open onto the arcades and courtyard, contributing to the conviviality of the whole. A more sober treatment illuminates the upper floors, where the doors and their frames are painted white, contrasting positively with the grey of the concrete, combining sobriety and luminosity in a contemporary spirit.

Project

The building fits naturally into the neighborhood plan and expresses a homogeneous, serene and sustainable architecture. Emphasis is placed on the quality of communal spaces, such as the entrance courtyard, with its alternating play areas, tree-lined zones and relaxation areas. The courtyard is framed by generous arcades that make it easy to meet people, a function also found on the upper floors.

The façade is treated as a large mineral monolith, reinforced by a play of offsets that makes it vibrate and gives it a character of its own. The precast concrete is composed of Neuchâtel aggregates, white sand compacted without pigment.

Its finish reinforces the mineral character of the whole. The stainless steel balustrades are composed of inverted Vs, alternating like chromosomes.

Realization

The project aimed to limit earthwork volumes by optimizing the subsoil. The open-ground zone becomes an open-ground zone on the slab, allowing the planting of major trees and avoiding the need to create a second basement. The static system is composed of reinforced concrete interior and peripheral load-bearing walls. The concrete structure contributes to the building’s thermal inertia and soundproofing.

As many rooms as possible benefit from natural light. A good form factor and a high-performance thermal envelope are proposed to minimize energy requirements from the outset.

Inside, the materials are simple, raw and of high quality: raw concrete walls and tiled floors in the distribution shaft, for durability. Wood/metal windows and parquet flooring throughout.

Exterior fittings

On the scale of the new district, the proposed outdoor landscaping fits in with the spirit of the spaces already created, reinforcing the overall coherence sought. The area in front of the new building is totally permeable and, with the exception of the driveway paving that provides level access, becomes a flowery meadow planted with street trees. The Promenade du Credo extends the existing axis to the east. Alternating cercis (often called Judas trees) and cherry trees planted in rows highlight the route and define the vocation of the spaces. Between two short flights of stairs, and taking advantage of the regular slope of the layout, a level access is created. Parallel to the Chemin du Bac, a line of oak trees forms the transition between the public space and the building.

A variety of fruit trees are planted freely in the garden on the east side of the building. The recently constructed stabilized gravel path is retained.

The courtyard, which can be traversed in all directions, alternates between planted green spaces, meeting areas and children’s play areas. Taking advantage of the open space between the surface and the underground parking lot, slight mounds are planted with a variety of trees, including serviceberry, birch and cherry. The site comprises two types of surface: impermeable, similar to the street, favoring accessibility, and permeable, including the green expanse and connecting paths. The aim is to promote absorbent, infiltrating surfaces, in order to reconstitute the function of the soil and improve the urban environment. The planting of stem trees and fruit species is consistent throughout the Marbriers district, as is the choice of street furniture.

Project challenges and strengths

The main challenges were keeping to schedule, coordinating all the parties involved and balancing architectural choices with the client’s requirements. Site decontamination proved necessary.

A particular highlight is the generosity of the communal spaces, from the arcades to the storey landings. In addition, the facade, treated as a large mineral monolith, reinforced by the play of offsets, is a striking feature of the project.