Social Housing - Gymnasium in Paris

ANTOINE REGNAULT ARCHITECTURE – France

Social Housing – Gymnasium in Paris

Building use

Other

Country/Region

France

Overview

The renovation of the Ilot-Saint Gemain in Paris includes the creation of 254 social housing units, a kindergarten and a gymnasium. The composite solution was used for the creation of the gymnasium roof.

Basic information (construction date, number of stories, gross floor area, adopted design code, engineer(s), Contractor(s), etc.)

Construction date: 2020-2023
Number of stories: 1
Gross floor area: 1,500m2
Adopted design code: –
Engineer(s): EVP Structure + Antoine Regnault Architecture
Contractor(s): GTM Bâtiment

Issue and/or innovation

Due to the small amount of space available inside the courtyard, the mandatory requirement of a certain amount of space of natural ground (for rainwater water absorption needs) was achieved by creating a planted garden above the roof of the gymnasium, which is otherwise excavated one story below the courtyards level. To this end, 120 cm of soil are needed above the roof. Additionally, the traffic conditions in the area and the limited space available on site for trucks requested the beams to be assembled on site, preventing the use of pre-fabricated beams.

Reason for composite solution

The composite solution was chosen due to loadbearing capacity required for the gymnasium roof. In fact, the creation of a vegetated garden with full-scale trees requested the provision of 1.2 meters of soil, that adds a significant weight to be carried by the 21-m long span beams.

Specific solution/technical details

23 prefabricated composite beams have been used for the roof of the gymnasium, each spanning 21 meters in length. Each beam was delivered by the Italian company Tecnostrutture divided in three sections, and was then re-assembled at the construction site to create a single span of 21 meters by means of bolted connections. Each beam was then hoisted to its final position without the need of temporary support elements that would have created an impediment on the construction site of the gym.

Impact or effectiveness

The fact that the beams have been assembled on site by simple bolting (no welding required) significantly facilitate the transportation through the congested streets of downtown Paris and also inside the construction site, where limited maneuverability of large elements was possible.
The use of composite beams (instead of other materials) allowed to limit the depth of the gym excavation to the minimum, allowing at the same time the load bearing capacity for the 20x30meter wide roof planted with trees on a 1.2m thick layer of soil (required for rainwater absorption needs).