HOSTA makes transforming a ring road around Greater Paris into a natural and vibrant urban boulevard look effortless. But construction in this tangle of urban infrastructure presents a web of architectural and sustainability challenges.

Thanks to Woodeum, a leading low-carbon real estate specialist and developer and a lightweight and robust Sylva™ by Stora Enso CLT building kit, there was a sustainable solution for Agence Hardel Le Bihan’s architectural design.

Hosta, will provide 114 bedrooms in a 7-storey hall of residence for young workers suspended over six lanes of traffic on the Porte Brancion when it opens in 2024

Given the location, had the building been constructed with concrete, it would have been so heavy that it could only be four floors high.

The mixed-use residential /educational space will also provide two commercial shops on the ground floor and is being built in conjunction with a 4-storey 3,500 m² sports building with public access and a 5-storey 3,875 m² student residence with 162 rooms and commercial retail space with 22 underground parking spaces.

Using prefabricated Sylva CLT Floors helps facilitate deliveries in the high-congestion area, where there is no room for on-site storage.

Delivery trucks are much smaller than heavy cement trucks so, the trucks can drive through the tight entranceway to the site with just-in-time, perfectly planned loads.

Each Sylva™ element was precoated with an insecticide according to code, which also helped ease the installation process. The coating was effective against wood-eating larvae (house buck, lyctus, rodent beetle), termites, fungi, and basidiomycetes (brown and white rot) and provided another layer of protection during transport, site storage, and installation.

In Woodeum’s and Stora Enso’s continued efforts to lower emissions, some of the Sylva™ CLT Floors were delivered by train. Only the "last-mile" was delivered by truck.

Transport emissions:

- Rail + last mile delivery: 8.1 CO₂e (kg)

- Road transport: 67.8 CO₂e (kg)

More than eight times less transport emissions than had the entire project been delivered by road.