Contractor

Name : Conseil Départemental de La Réunion

 https://www.departement974.fr/

Construction Manager

Name : LAB Réunion

Contact : Cédric Delahaye

 https://labreunion.fr/

Stakeholders

Function : Thermal consultancy agency

LEU Réunion

 https://leureunion.fr/


Environmental design office

Function :

LET Réunion

Patrice Chane-Pane

 https://letreunion.fr/

Function : Other consultancy agency

INSET

Eric Ottenwelter

 https://www.inset.fr/

Function : Other consultancy agency

OMEGA

Function : Other consultancy agency

ETBT

Contracting method

Separate batches

Type of market

Global performance contract

Allocation of works contracts

Separate batches

Energy consumption

• Primary energy need : 132,00 kWhep/m².an

Calculation method : RTAA DOM 2016

Envelope performance

More information :

The U-bat is unsuitable in a tropical climate, the objective here is to protect the envelope from direct solar radiation. For this, the use of sunscreens optimized according to the orientation of the sun is systematic, likewise all the bays are protected by solar protection.

Users' control system opinion :

Active home automation systems were not installed on this project or we preferred passive systems (user actions). Indeed, home automation is fragile and delicate to use in this type of establishment and subject to planned obsolescence. In addition, it relieves users of responsibility.

More information

No real estimate at this stage, the establishment having not yet reached its maximum capacity.

Non-renewable primary energy consumption

Non-renewable primary energy consumption : 92,00 kWhep/m².an

Systems

Heating system :
• No heating system
Hot water system :
• Solar Thermal
Cooling system :
• No cooling system
Ventilation system :
• Natural ventilation
• Nocturnal ventilation
Renewable systems :
• Solar Thermal

Smart Building

BMS :

Passive building without systems with planned obsolescence and costly maintenance.

Users’ opinion on the Smart Building functions :

Very happy because they have nothing to manage except the alarm!

Biodiversity approach

This project deploys, thanks to the expertise of the landscaper Michel Reynaud, an advanced strategy of renaturation of the site.

Originally, a dry savannah, degraded and invaded by plant pests. The renaturation of the site for ecological and thermal purposes was one of the strong points of this project, as the photos illustrate better than a long speech. The vegetation lining the ditches and the infiltration basins also participate in the management of rainwater, on a sloping site where rain events can be exceptionally strong (cyclonic zone), in the twenty-seventh case. Thus, all rainwater is contained on the site.

The percentage in U2c of permeable free spaces is 50% of the free spaces:

• Surface area of land 17,947 m² (AU zone) excluding N zone (excluding forecourt and spaces for external access);
• 7,646 m² of gardens in the ground outside the N sector;
• All of the garden courtyards are wooded and permeable and represent 1685 m²;
• Grass slab parking lots: 125 m² (not counted as permeable - indicative);
• Sandpits on draining underlay 58 m² (a sports field and the track are not permeable because they are planned in a sports resin finish on a low-draining concrete support);
• That is a theoretical total of so-called permeable wooded soil of 9,330 m²;
• That is a total of permeable free spaces equal to 51.98% of the total surface of the plot (excluding zone N).

Mitigation actions on soil and biodiversity :

Permeability

The organization of the plan makes it possible to preserve a maximum of the surface of the ground in permeable spaces. Rainwater management is based on compliance with European regulations (see extract from framework directive 2000-60), namely:

• Depollution of rainwater and runoff (residual urban water);
• Availability for the terrestrial environment (refilling the environment and aquifers);
• Protection for the marine aquatic environment, and in particular the ecosystems of the lagoon.
   

These three main principles, to which is added that of the timing of major events for the protection of environments and people and property downstream (hydraulic risk in an intense event) - the only one really taken into account in the current regulations applied in France) determine in the end:

1. The constitution of permeable pedestrian soils: courses in synthetic grass placed on a bed of sand and a draining subgrade.
2. The integration of car parks and the treatment of risks by a separator (or internal trapping in a bed of gravel), supplemented by an external pollution control device (discharge into a natural wooded environment) in the event of a malfunction.
3. The best limitation of the spaces available for vehicles (a single firefighter and service lane within the operation).
4. The realization of rainwater management by occasional drains (infiltration in roof downspouts) and by systems of temporization terraces, valleys, (...) planted allowing phytoremediation (bioremediation of carbonaceous, nitrogenous and sulfur pollutants, and phytostorage of xenobiotic particles heavy metals and chemical metabolites).
5. The definition of landscapes in plant density with gentle differentiated management mode (without fertilizers, without phytosanitary products, without heat engine tools), intended to reinforce the wooded systems and the structure of the humic soils (trapping and retention of water, fixation in clay-humic complexes of toxic metabolites extracted from biogeochemical cycles (neutralisation)).
6. The construction of vegetated terraces on the roofs (heteropogon savannah) forming a "buffering" of low to medium intensity rainfall. The principle of water management in a simplified way is as follows for the types of precipitation (see hydraulic notice):
   - Low occurrence (one year): depollution, feeding of surface substrates (episolum humifère);
   - Intermediate to high occurrence (decadal): temporization and retention by infiltration, recharging of terrestrial environments and depollution, trapping of particulate pollutants, and depollution for the recharge of aquifers;
   - Exceptional occurrence (from 20 to 100 years): temporization and buffer storage at the end of infiltration and phase shift of flows in the outlets. Respect as close as possible to the original outlets determined by the topography of the place.
    

Note: the Roquefeuil college sector is positioned in the SDEP of Saint Paul in a low constraint zone (yellow color on the map opposite), the compensation for the part of built waterproofing and roads having to be treated by a limitation of rejected flows, ie flow after development = initial flow.

Risks

Hazards to which the building is exposed :
• Flooding/Runoff
• Earthquake
• Wind / Cyclone

Risks measures put in place :

• The choice of buildings with a metal structure greatly reduces the oscillating masses and thus the efforts in the foundation (optimization of the foundation concrete). The flexibility of the steel and of the facades in filling in the dry die avoids the appearance of cracks.
• The dimensioning for cyclonic winds (250 km/h) ensures good protection of the structure.
• The textile cover of the gymnasium limits the risk on the structure, the cover being able to serve as a fuse before the structure is destroyed.
• Twenty-year rainwater management (see above).

Urban environment

The project is located at the high point of a joint development zone, it dominates the site and thus benefits from the views and above all from a good potential for natural ventilation (no masks built around).

The organization on the site limits earthworks and optimizes the slope, thus reducing visual impacts.

Access to buses, pedestrians and bicycles (cycle path) has been designed in such a way as to easily serve the equipment from the district and the surrounding area. A bus station is positioned opposite the main access.

• Land plot area : 18 847,00 m²
• Built-up area : 48,00 %
• Green space : 9 330,00

Product

Steel sheet cover



Ondulit

 http://www.ondulit.com/fr/ondulit.html


Product category : Structural work / Carpentry, cover, titghtness

Steel sheet with natural aluminum reflective complex with excellent solar factor (reflects 90% of radiation), acoustic reduction of around 25dB and excellent resistance to salt spray and corrosion

Simple technology of implementation, equivalent to a traditional sheet.

SMC2

SMC2

 https://www.smc2-construction.com/


Product category : Structural work / Carpentry, cover, titghtness

Integrated textile structure system for large gymnasium-type spans with textile cover.

A solution allowing an optimal quality of natural lighting in a gymnasium, with a great homogeneity of natural lighting.

Construction and exploitation costs

• Total cost of the building : 18 000 000 €

Water management

The toilets are supplied by Presto-type timed systems, which limits consumption.

Indoor Air quality

The choice of buildings with natural comfort ventilation (air renewal rate of around 50Vol/hour) ensures excellent renewal of indoor air and therefore contributes to very good air quality.

The choice of low-emission acrylic paints and recycled PVC floors (Gerflor) with resin encapsulating VOCs contribute to this quality.

Comfort

Temperature level :

The climate of Roquefeuil (source meteo France) gives maximum average temperatures of 32°. Thanks to the strategy of natural comfort ventilation (low built thickness of less than 10m, high porosity of the facades, greater than 30%, solar protection of the envelope, roof overhangs, solar protection of bays, sunscreens, greening of the surroundings of buildings, 70% of the linear facades, installation of ceiling fans for windless days), the temperature felt is a maximum of 28°C, which guarantees comfort without recourse to artificial air conditioning and is observed after two seasons warm to use.

It is indeed a global passive aerothermal design that has been deployed here.

Humidity control :

Operation in natural ventilation with airflows of the order of 50Vol/h allows the humidity generated by the occupants to be evacuated, the air speed optimizing this control.

The high porosity of the student toilets ensures excellent hygrometric comfort and limits, or even eliminates, bad odours.

Acoustic comfort :

Acoustic comfort has been the subject of specific attention at two levels:

1. For buildings: use of an insulating sheet (Ondulit) reducing the impact noise of rain and airborne noise by around 25dB. The addition of acoustic insulation on the underside of the sunscreens in the classrooms, limiting airborne noise from the courtyard.
2. For the facilities: the vegetation on the outskirts of the buildings improves the reverberation time and thus limits the nuisance in the classrooms which have the windows open for the VNAT.
    

The relative isolation of the college greatly limits road noise.

Visual comfort :

The low thickness of the buildings ensures excellent autonomy in natural lighting. The systematic presence of solar protection prevents glare.

The use of a white textile cover for the gymnasium ensures excellent homogeneity and quality of natural lighting, drastically limiting the use of artificial lighting.

Ergonomic design :

A specific reflection was carried out for the comfort of the courtyards with the design of a large bench of wooden urban furniture, which also allows the infiltration of water from below.

The ergonomics of the maintenance of the toilets has also been designed to allow intervention from the outside of the toilets thanks to a removable facade giving access to the waste and drinking water networks.

• Degree-hours of discomfort : 200,00 °C.h.

Carbon sink

The large proportion of plantations, and in particular of tall trees (see elsewhere), allows carbon to be stored in the long term.

Initiatives promoting low-carbon mobility

• Bicycle parking is organized and secure at the entrance to the establishment;
• A cycle path and a generous sidewalk accompany these gentle journeys;
• A bus station is provided opposite the entrance to the establishment.

GHG emissions

• Building lifetime : 50,00 année(s)