Social housing apartments

Quartier Mermoz / Lyon / France

The Tectoniques architectural firm has been awarded the French Academy of Architecture and National Order of Architects’ Housing Award 2018, for all their work in this field and their thinking on housing. This prestigious award coincides with the delivery of a block of 55 social housing apartments in the Mermoz neighbourhood, at the heart of the eighth district of Lyon. 

However, Tectoniques was a latecomer to collective housing. From the outset the firm specialised in dry and wood construction and obtained its first orders in the construction of facilities. For two decades wood construction and collective housing were widely considered to be incompatible. Today, there has been a genuine paradigm shift! Increasing numbers of housing projects use a variety of wood construction processes which provide responses which offer an ever better fit with modern living standards, and in particular with the desire for improved environmental performance (short distribution channels, bio-based materials, reduced worksite duration and disturbance, modular buildings etc.). 

Composed of two buildings known as “Delta” and “Foxtrot”, the project on the Mermoz mixed development zone concentrates all the principles governing how the architects design and build people’s homes today. 

In urban planning terms, the Lyon Mermoz project is the flagship for the revitalisation of the eastern access to the city of Lyon. This work began over a decade ago when the motorway bridge linking to the A43 was demolished and the roadway requalified as a landscaped urban boulevard. This major regeneration project has ambitious goals both in quantitative terms, and in terms of the quality of the programme and image of the neighbourhood. The Mermoz North mixed development zone is the first stage in this transformation process. Across 6.5 hectares of land, 318 existing housing units were demolished, whilst others were preserved and renovated, and 12 new-build programmes were launched to diversify the housing offer and social mix.

Staying the course

Despite the already stringent specifications (dimensions, density, volumes, openings, depths, thickness of the built volumes etc.) the architects also wanted to include features essential to comfortable living: corridors with natural light and ventilation, staggered entrances to mark a break between the public and private spaces, no blind hubs, dual or multiple aspect apartments, comfortable outside spaces and, of course, the use of a mixed construction using materials where they offer the best performance. 

They also wanted to avoid a stereotypical basement-main body-attic structure and so chose to build a double attic with a sloping roof, breaking with the horizontal lines that dominate the neighbourhood, opening up new perspectives and streamlining the bulk of the buildings. 

The 55 apartments are split between two small buildings (blocks 21 and 26) with 22 and 33 apartments respectively, retail space on the ground floor running along avenue Mermoz (block 21), cycle sheds on the street and underground parking spaces.  

The blocks are not positioned opposite one another. Block 21 has a more urban location on the corner of avenue Mermoz and rue Boselli. Block 26 closes off the northern boundary of the mixed development zone. Both are laid out in the same way, two buildings connected by vertical accesses, with natural light and ventilation, enveloped in a metallic, grey, perforated and folded skin. The perforated metal sheets created a veiled effect and are transparent from the inside and opaque with shifting colours when viewed from the street. The feel inside is light, serene, and soft without ostentation.

There are four apartments on each floor. Each apartment has a large balcony of 9 to 15 m2 angled to avoid being overlooked.

Using the light/heavy relationship

In terms of construction, the project pushes the use of mixed materials to its limit: concrete for the basement and load-bearing walls; wood frameworks for the partitions and facades; and a mixed wood-metal structure for the components of the facade. The wood framework walls were prefabricated by Rubner. The facades, produced using prototypes, contain all the different materials and systems used.

Playing with duality 

The designers aimed to develop a different architectural language by favouring materials with a dual perception: matte or satin, light or heavy, playing with light colours and effects which change with the light. The golden metal shutters, balcony partitions and storage, contrast with the mineral, matte effect of the fibre panels, whose vertical arrangement creates a very precise pattern on the façade. The lacquered, perforated metal used for the guardrails enhances the warmth generated by the wood used for the balconies and the woodwork.

55 social housing units
Lyon / North Mermoz district
Lots 21 and 26 Delta & Foxtrot

Total SDP: 4,597 M2
Cost of works : 5,8 M€HT

Client : Grand Lyon Habitat

Commissioned Architects: Tectoniques Architects
Associate architect: Julien fontaine
BET: Tectoniques engineers
Inddigo environment
ETBA structures

Built in 2017
Photographers: Jérôme Ricolleau (royalty-free photos)

Environmental performance (under RT 2012)
Cep < 42 kWhep/
Share of renewable energies above 40% of the global energy balance
Airtightness requirement: Q4 < 0.3 m3/h.m2 and n50 < 0.6 vol/h
Insulation rating: 0.55 < 0.7
Ratio of glazing area and SHON: 0.18

The Foxtrot building (building 26) was selected under the national call for E+C- projects.
The Delta building (building B21) was selected for the Energie Carbone experiment in Auvergne Rhône-Alpes (OBEC- AURA).

Main products:

Mixed wood-concrete-metal structure
Wood used for the balconies: cross laminated timber panels Binderholz BBS
Wood frame bracing panels:  FERMACELL
Cladding: Equitone / Tectiva panels certified NF FDES-PEP for use on wooden frameworks
Insulation mineral wool for wooden frameworks:  KNAUF Classic 035
Shutters: BSO GRIESSER   + DURMI folding shutters
District heating
Sanitary fittings: PORCHER certified NF CSTB
Electrical fittings: LEGRAND certified NF FDES-PEP