Green Cascade: the urban block revisited in Lyon, France

The urban block revisited
The project takes the place of the demolished former Keller-Dorian factory (built in three stages, in 1895, 1928 and 1960), which produced small metal items for engraving on metal, particularly for the rolls required in textile printing.

Observing urban planning regulations, the scheme proposes a new interpretation of the urban block, which, with alternating solids and voids, succeeds in maintaining street frontage while preserving a visible, landscaped inner court that runs through from one side to the other. This large scheme is made up of five small buildings placed in a tiered garden. The simple, unified architecture is in keeping with the soft, harmonious atmosphere of the external spaces.

What the client says:
Nicolas Ducrohet, Programmes Director
Cogedim Grand Lyon builds around 450 homes every year. Green Cascade is a relatively large scheme. 20 apartments are for the HMF social housing agency, 2 are reserved for Habitat & Humanisme, and the remaining 78 are sold to private individuals. The scheme consists mainly of small housing units, which is a general trend in the city centre.

“Construction work was completed very rapidly for the first-rate redevelopment of a polluted industrial site with high-quality homes. The architects succeeded in exploiting regulations concerning both urban planning (“URM” zone) and architecture (set-back penthouses). Everything was done to create a living environment that meets the criteria of modern comfort: the human scale of the buildings, their aspects, the balance with the garden, the housing unit modules, and the very adaptable large sunny balconies.”

Urban street frontage, landscaped inner court
Regulations concerning the “URM” zone, defined by the Local Urban Development Plan for the Greater Lyon area, suggests a principle of an urban form based on an entirely renewed conception of the urban block. The traditional urban block is closed, with continuous façades that create a linear street front while freeing an open central inner space, cut off from the street.

On the other hand, the principle of the “URM” zone is based on the alternation of construction and voids. It maintains a city centre street front together with framed, highlighted views onto a landscaped inner court space. Two characteristic atmospheres respond to and complement each other: urban on the street side, and landscaped in the inner court space. Light passes through the entire constructed thickness, providing daylighting of each small block. The other specific characteristic of the “URM” zone regulations is that they allow building within the central space.

The scheme is made up of five small blocks, four of which are on the three streets (Rue Antoine Charial, Rue Saint Eusèbe and Rue de l’Espérance), and one low building without penthouses in the central garden area. A plinth and a garden with tiered terraces were included due to a significant difference of level (4m) between east and west.

What the neighbours say:
Raphaël has lived at 149 Rue Charial since 1985. No. 149 is just above the entrance to building D, which is on the corner of Rue Charial and Rue Espérance. He witnessed the demolition of the first part of the Keller-Dorian and the construction of the eight-storey building opposite. He answered my questions: “It’s a nice change! The apartment blocks remain very low in relation to the rest of the neighbourhood. The city is becoming more built-up, but it’s keeping its greenery.” Pragmatically, he added: “The building work went well. It didn’t cause any particular inconvenience… And the quality of construction appears to be very reliable!”

Today’s apartment housing: a place for mixing
Nowadays, apartment housing projects are based on the principle of providing mixed accommodation, in terms of both the range of housing units and the social mix. The housing units are divided among five plots. They are designed according to the separation of daytime and night-time spaces, always preferring a double aspect, including one side facing south. They are made up of easily adaptable large rooms, and they have large balconies.

While the four buildings facing onto streets are more or less similar in terms of the range of sizes of their apartments, the building in the inner court area is based on other principles. It only consists of single-bedroom apartments, accessible via access balconies and stairs, covered by a steel roof. The façade of this three-storey building recalls that of the penthouses, with an external skin made up of larch battens. Despite their small size, the apartments also have large balconies, which are the scheme’s distinctive features.

In terms of social mix, most of the scheme is designed for first-time buyers, including some subsidized homes for first-time buyers. Building A is for rented accommodation.

In accordance with the Local Urban Development Plan, the penthouse, the dream roof-top home, is constructed by setting back the top floor or the top two floors in relation to the main facade. It has the advantage of minimising the building’s height as seen from the street, while also possibly concealing services plant on the roof and freeing large continuous balconies. The top floors become real houses on the roof, with commanding views. The apartments are extended by spacious balconies in timber slats laid on props. Their comfortable 2 m width makes them real outdoor lounges.

What the occupants say:
Marie Jane is the tenant of a small apartment on the 5th floor of 128 Rue Charial. “Aesthetically, I liked these different buildings very much. The gaps between the blocks remind me of an old building with wings separated by gardens. The wood finish goes well with the refined garden, which is planted with trees and plants that are rare in Lyon”.

Léna lives in a two-bedroom apartment on the ground floor of building C: “Having moved house nineteen times, I can say that these apartments are very well designed. Our spacious balcony is very pleasant, facing due south, with no buildings looking onto it. The large shaded windows provide external views while keeping the interior very cool. The sound insulation contributes to comfort that you don’t have in old buildings.”

Playing with few effects
In this context, the architects opted for a scheme that is discreet and unostentatious. The architectural style and the forms are simple. “Space is luxury” is a concept that ensures the occupants’ comfort. The scheme uses few materials, but high-quality materials that are carefully applied with attention to detail.

The buildings are composed of three strata. Firstly, a concrete plinth with a dyed and textured moulded finish is formed by a resin mould that shapes the vertical elements, giving it a dynamic visual effect, accentuated by a recessed joint. The horizontal plinth takes up the changes in level. Secondly, this ground floor supports the main body of the building, consisting of two floors of simply rendered concrete. Thirdly, these floors are topped by a single-storey or two-storey penthouse, whose external walls are covered with wooden battens placed vertically so that there are 50% voids and 50% solids, to comply with fire regulations.

On the street side, the repetitive large 210 x 240 cm openings recall the style of the former factory. On the inner court side, the choice and combinations of materials produce a delicate graphic effect. A play of lines is created between the expanded metal guard rails, the horizontal sun louvers, the wood façades and the wood on balconies.

What artists say:
Elisabeth Berthon and Chloé Lecoup, felt artists from Morse Felt Studio, created four works that are placed in the buildings’ entrance halls. Made with felt panels mounted on frames of different sizes, they are all variations on the same theme. They integrate perfectly into the scheme with their colour, softness and plant material, in colored harmony with the floors, walls and letter-boxes.

Felt is the oldest textile fabric in the world. It is a strong, non-woven, non-tearable material made with three things: wool, rubbing and moisture. Made from local wool, it is a natural material with many enviable properties: biodegradable, warm, and providing acoustic insulation. The composition of the panels is based on the migration of tannins and pigments of different qualities of dry eucalyptus leaves on the wool.

“Making wool felt panels, then printing the imprints of eucalyptus leaves on them in a contemporary housing scheme that is sensitive to the comfort of non-polluting materials, searching for a better quality of life, gives meaning to our work. We want to make wool central to this search for comfort in simplicity. This is a priority of the Atelier de la Passerelle approach. The smell of the eucalyptus mixed with that of wood evokes nature in the heart of the city.”

The garden laid out in strips reflects the pattern of plots in the neighbourhood
The garden is one of the key elements of the scheme. Designed and laid out by the Atelier Anne Gardoni firm, it is arranged on the entire plot according to a principle of strips that reflect the neighbourhood’s inner suburb layout. Its design was guided by three principles. First of all, the optimisation of the gaps and spaces between constructions, planted with standard trees and visible from the street, creates marked contrast between architecture and nature. Then the layout in strips proposes different materials and different uses. For example, alleys between buildings or rows of bushes provide privacy for the homes. The garden includes trenches for rainwater infiltration, in the form of channels. It takes up the 4 m change in level by creating tiered terraces and freeing outdoor lounge areas on timber decking. The third point concerns the interstitial spaces between the entrance halls of buildings and the street, which are treated as “small inner courtyards” or light wells, with climbing plants, ground cover plants and a paved floor. In continuity with the landscape in strips, the roofs will be planted with sedum [stonecrap]. The harmony of the chosen materials creates a soft, calming atmosphere for a very quiet inner court area.

What the architect says: “When we design a scheme, the user is central to our thinking. We bear in mind the users’ comfort, and we think of how they will make this housing complex their own, and what environment they will observe every day. Above and beyond the scheme, the practical and pragmatic aspects, and the dual competencies of client and project manager required by such a scheme, we are aware that, first and foremost, we are building a place for living and for interaction. As time goes on, the users will gradually make this place their own, and “this building” will become “our building” and “our home”. So we try to “see“ through their eyes and to feel as they will feel, while respecting the surrounding urban context and complying with the client’s specifications. Our schemes are produced with great care, but no two are the same, because we choose to be guided by a rationale of composition that aims to give the project its identity.”