Headquarters of the Order of Architects Réunion / Mayotte

Extension + refurbishment

  • Building Type : Office building < 28m
  • Construction Year : 2022
  • Delivery year : 2022
  • Address 1 - street : 92 rue de la république 97400 SAINT DENIS, France
  • Climate zone : [Af] Tropical Wet. No dry season.

  • Net Floor Area : 110 m2
  • Construction/refurbishment cost : 247 350 €
  • Number of Work station : 7 Work station
  • Cost/m2 : 2248.64 €/m2
  • Primary energy need
    85 kWhep/m2.an
    (Calculation method : RTAA DOM 2016 )
Energy consumption
Economical buildingBuilding
< 50A
51 à 90B
91 à 150C
151 à 230D
231 à 330E
331 à 450F
> 450G
Energy-intensive building

This project won the Grand Prize in the "Tertiary Buildings" category of the Circular Buildings Trophies 2022.

On the occasion of the competition for the restructuring of the Headquarters of the Order of Architects, we choose to present not a project, but an approach. That of reuse. The opportunity is perfect, a small scale, perfect for trying out the practice, and a project management more than well placed to support the concept. Taking into account the many riches of the island, we specify our commitment to ethical architecture : what will not be reused will at least come from raw materials from Reunion Island. Using word of mouth, we set foot in a network of actors already well engaged in the process.

The project involves renovating and raising a "concrete hut" typical of 21st century Reunionese architecture.

Building users opinion

Not occupied so far.

If you had to do it again?

We would do it again! Even if the pioneering approach in Reunion makes the realization of this small operation fragile, constantly on the wire: resources to be secured every day, financial balance and deadline difficult to meet in the event of disappearance of resources or difficulty of implementation requiring adaptations of supply. Adherence to the approach with all stakeholders is to be reminded daily. The reuse sector being non-existent on the island, we underestimated the time spent searching for resources and securing them: - Provide a "reservation" position for resources during the study phase (delivery and carrier) to ensure the resource. We had a possible storage in the existing house to be rehabilitated, we under-exploited it for financial reasons (work budget not released during the studies and study contract not having provided for this item); - Impose the visit of the site and therefore of the recovered materials to the companies subject to the reuse operations for financial optimization and anticipation; - Check the storage of deposited materials.

See more details about this project


Photo credit



Construction Manager


    Other consultancy agency



    Structural design office

    Environmental consultancy












    Rehabilitation / Structural work




    Green spaces

Contracting method

Separate batches

Type of market

Design and implementation

Allocation of works contracts

Separate batches

Energy consumption

  • 85,00 kWhep/m2.an
  • 85,00 kWhep/m2.an
  • RTAA DOM 2016

    final energy breakdown: ceiling fans (4.5), interior lighting (7), computer workstations and various power outlets (20), exterior lighting (1.5)

  • 140,00 kWhep/m2.an

Real final energy consumption

    33,00 kWhef/m2.an

    33,00 kWhef/m2.an

    2 022

Envelope performance

    No home automation system is installed.


    • No heating system
    • No domestic hot water system
    • No cooling system
    • Natural ventilation
    • Free-cooling
    • No renewable energy systems

    Le projet a été conçu en ventilation naturelle, tirant profit des brises thermiques traversant le territoire. Les façades largement poreuses permettent le passage de l'air et le ressenti d'une température diminuée.
    Ce dispositif est complété par des protections solaires efficaces.
    De plus, les façades Ouest et Est sont pensées en pignon opaque, limitant ainsi la surchauffe lié à l'ensoleillement (à la Réunion, ce sont ces façades qu'il faut protéger au maximum). Les façades nord et sud, elles, bénéficient de larges ouvertures protégées par des brises soleil horizontaux complétés au sud par des joues de protection solaires.

Urban environment

  • 328,00 m2
  • 27,00 %
  • 180,00
  • The project is located in the Bas de la Rivière district in Saint Denis, the capital of the island. It is a historic district that has left its mark on the City and still includes historic facilities and buildings such as the “Turtle Fountain” erected in 1937 on the Place Fontaine Tortue, at the foot of the Ti Quat' Sous 1 staircase. This place appears in the sketches of the Creole poet Georges Fourcade.

    The project is located on Rue de la République opposite the former Collège Reydellet, previously "Jardin du Roy" (then the Governor's). A little further, we find the rue de la boulangerie, where a bakery (also royal) and a mill fed by a diversion of water from the river were established for a long time, the remains of which remain.

    This district is particular in its topography: it is indeed fully disbursed in relation to the city center. Old arrangements of ramps and stairs remain. But in order to effectively connect these two parts of the city for everyone, a vertical layout of traffic and parking lots has been built to revitalize the Lower River district. Thus, from the panoramic lift, we can observe the remains of the mill canal.

    The project is therefore located in a lively residential area composed mainly of individual dwellings or small collectives, local shops and school facilities such as primary and nursery schools.

    It takes advantage of the particular microclimate created by the Saint Denis River flowing into the ocean.


    Passive cooling solution: natural ventilation

    Structural work / Passive system

    The project works passively: in fact, no installation or system is planned to provide thermal comfort to users.
    The design is based on the foundations of tropical bioclimatic architecture: through natural ventilation and solar protection.
    The existing house is therefore renovated in this sense: partitions are removed in favor of trellises in order to promote natural ventilation, the shutters are rehabilitated for solar protection, air blowers are put in place to ensure cooling throughout. of the year.
    The elevation was designed to meet these two objectives: the reused joinery was redesigned to allow an opening favoring natural ventilation. A compass system allowing easy and constant opening during use.
    A solar protection principle completes the system (see below).

    Not occupied so far.

    Passive solution: sun protection

    Structural work / Passive system

    As mentioned, in order to guarantee passive thermal comfort to users, we must imperatively protect the facades with an effective system of solar protection in bioclimatic architecture.
    Thus, the shutters of the existing house are restored and put into service.
    The design of the elevation develops solar protections offset from the facade in local materials: frame in cryptomeria (local wood) creating cheeks perpendicular to the facade, supports for horizontal blades in the face of the facade in cryptomeria essence for protection North / South and whose interior filling is made of pallet blades for East/West protection.
    This effective device associated with natural ventilation supplemented by a system of air blowers provide real comfort to users.
    Added to this is the landscaping of the plot essential to the device.

    Not occupied so far.

    Air blower



    HVAC, électricité / ventilation, cooling

    The climatic context of Reunion and a responsible bioclimatic architectural design will always ensure fluctuations of incoming and outgoing air (open permeability) which will solve the problems of air quality and evacuation of internal thermal loads.
    On the other hand, for certain windy geographical areas or for certain periods of the year when the wind is weak, the ventilation strategy developing natural dynamic irrigation currents will need to be assisted. We will then use the ceiling fan.

    This solution is implemented on the Order's Headquarters project with one ceiling fan per office or work area/small meeting.
    The Council Chamber will have 4 ceiling fans to ensure real comfort for all occupants.

    Not occupied so far.

Construction and exploitation costs

  • 33 557
  • 247 350
  • A significant part of the budget (€94,000) corresponds to installations and overheads, road and utility works and above all reinforcements of the existing structure (€54,000).

Reuse : same function or different function

    • Structural framework
    • Roofing
    • Facades
    • Locksmithing-Metalwork
    • Outdoor joineries
    • Floorings
    • Electricity
    • Landscaping
    • others...

    • Sheet metal roof: 84m²
    • Wood frame: 6m3
    • Wooden floor: 55m²
    • Exterior joinery / Glazed doors with wooden frames: 11 units
    • Exterior joinery / Windows with wooden frames 4 panes: 4 units
    • Exterior joinery / Wooden frame windows transom window: 4 units
    • Interior door - Wood: 1 U
    • Metal railing: 18mL
    • Sanitary: 2 units
    • Sinks / washbasins: 3 units
    • Mirrors: 1 units
    • Sanitary accessories: 1ENS
    • Closings:17mL
    • Exterior flooring: 120m²
    • Sunscreen side panels: 24 SET
    • Three-row horizontal brise-soleil: 11mL
    • Earthenware: 3m²

    Sheet metal roof : 84m² - Submitted by S2R (company holding the GO lot) for the elevation of the Clinique Sainte Clothilde (Réunion), reused.

    Timber frame : 6m3 - Scrap from stock from the EBOI company (holder of the frame lot), reused for the timber gantries sized according to the available sections.

    Wooden parquet floor: 55m² - Wooden slats removed following the rehabilitation of the Pont de la Rivière de l'Est (Réunion), reused for indoor use.

    Exterior joinery / Glazed doors with wooden frames : 11 units - Joinery from the rehabilitation of Clinique Sainte Thérèse (Réunion), reused.

    Exterior joinery / Windows with 4-pane wooden frames : 4 units - Joinery from the demolition of Gîte du Volcan (Réunion), reused.

    Exterior joinery / Windows with wooden transom window frames : 4 units - Joinery from the demolition of the Gîte du Volcan (Réunion), reused.

    Interior door - Wood : 1 U - moved on the project, reused.

    Metal railing: 18 mL - Deposited as part of the elevation of the Sainte Clothilde Clinic (Reunion) reused for the same use.

    Toilets : 2 units - Removed as part of the rehabilitation of the Lycée de la Renaissance (Réunion), reused.

    Sinks / washbasins : 3 units - Removed as part of the rehabilitation of the Lycée de la Renaissance (Réunion), reused for the same use.

    Mirrors : 1 units - Removed as part of the rehabilitation of the Lycée de la Renaissance (Réunion), reused.

    Sanitary accessories : 1ENS - Deposited as part of the rehabilitation of the Lycée de la Renaissance (Réunion), reused.

    Fences : 17 mL - Brises soleil deposited as part of the elevation of the Clinique Sainte Clothilde (Réunion), reused as a fence.

    Exterior floor coverings : 53 m² made from rubble from demolitions or reusing floor tiles deposited on site, reused.

    70m² made from asphalt slabs deposited as part of the rehabilitation of the Lycée de la Renaissance (Réunion), reused.

    Sunshade sides: 24 ENS made from wooden slats taken from pallets, resold by Ecopal, reused.

    Horizontal brise-soleil in three rows : 11 m, made from wooden slats taken from pallets, resold by Ecopal, reused.

    Earthenware : 3 m² from waste from S2R site stock, reused.

Environmental assessment

    The data below is given in Kg

    Sheet metal roof: 84m²

    • eq Kg CO2: 2066.15
    • water: 0.02
    • waste: 5024.92

    Wood frame: 6m3

    • eq Kg CO2: 902
    • water: 14.5
    • waste: 788

    Wooden floor: 55m²

    • eq Kg CO2: 152.53
    • water: 3.42
    • waste: 257.79

    Joinery: 18.02 m² [ Exterior joinery / Glass doors with wooden frames: 11 units / Windows with wooden frames with 4 squares: 4 units / Windows with wooden frames with glass transom: 4 units ]

    • eq Kg CO2: 11141.77
    • water: 10.37
    • waste: 1421.87

    Metal railing: 18mL

    • eq Kg CO2: 1671.46
    • water: 11.61
    • waste: 821.56

    Sanitary: 2 units

    • eq Kg CO2: 136.94
    • water: 2.22
    • waste: 123.84

    Sinks / washbasins: 3 units

    • eq Kg CO2: 270.66
    • water: 2.60
    • waste: 161.56

    Mirrors: 1 unit

    • eq Kg CO2: 14.19
    • water: 0.03
    • waste: 10.60

    Sanitary accessories: 1ENS

    • eq Kg CO2:
    • water :
    • waste :


    • eq Kg CO2: 6881.07
    • water: 43.69
    • waste: 6504.59

    Exterior flooring: 120m²

    • eq Kg CO2: 5798.73
    • water: 25.22
    • waste: 14431.01

    Closures and solar protections: 61.55 m² [ Sunshades cheeks: 24 ENS / Horizontal sunshades on three rows: 11 ml ]

    • eq Kg CO2: 2508.16
    • water: 42.94
    • waste: 1207.02

    Earthenware: 3m²

    • eq Kg CO2: 47.56
    • water: 10.15
    • waste: 98.06

    Office furniture: 2 U

    • eq Kg CO2: 218.03
    • water: 2.28
    • waste: 151.63

    Lighting - Industrial suspension: 10 U

    • eq Kg CO2: 1738.16
    • water: 14.22
    • waste: 2154.82

    Interior door - Wood: 1 U

    • eq Kg CO2: 104.98
    • water: 97.81
    • waste: 130.63

    The reuse operation saved the equivalent of 25,273 kilometers traveled by a small car, or 215 Paris-Nice journeys, 1,875 rectangular bathtubs filled with water and 67 years of household waste.

Economic assessment

  • 26 %
  • 23 385

Social economy

    Several materials such as the joinery of the Clinique Sainte Thérèse were supplied by Synergie Péi . Synergie Péi is an experimental approach of Industrial and Territorial Ecology (ITE). It is a pillar of the circular economy, industrial and territorial ecology is an operational approach which aims to promote the pooling, reuse, reuse and recycling of industrial resources to optimize their use and reduce their footprint. environmental.

    Materials not used on site were recovered by the ADRIE Ressourcerie . It is a member of the Réseau des Ressourceries and has an ACI (Atelier Chantier d'Insertion) Ressourcerie. This allows the association to employ people in social and professional difficulty. An order for furniture was made to them, reusing the materials recovered on site.

Reasons for participating in the competition(s)

Ce projet consistitue le tout premier projet réalisé en réemploi sur l'île de la Réunion. Accompagné des entreprises en charge du projet (EBOI, S2R et Paysages), les architectes se sont attelés au sourcing des matériaux, alimentant en parallèle le dessin. De nombreux allers-retours ont été nécessaires afin de finaliser le projet.

Les façades de la surélévation seront constituées de menuiseries issues de la déconstruction du Gîte du Volcan et de la Maternité Sainte Thérèse. La toiture tôle provient de la surélévation de la Maternité Sainte Clothilde, le plancher bois est constitué du platelage du Pont de la Rivière de l'Est. Les brises soleils utilisent du bois de palettes recyclé et traité. Les équipements sanitaires sont également issus du réemploi

Nous utilisons également les rebus de stock. Ainsi, la charpente a été dessinée à partir d'un stock de bois de l'entreprise titulaire du lot EBOI. Le carrelage provient de surplus de chantiers S2R.

Dans le cadre des démolitions sur site (petits apentis et revêtements de sol), ces derniers seront utilisés en remblais pour permettre l'accessibilité PMR, et en revêtement de sols extérieurs. 

Les tubes métalliques soutenant les petites toitures ont été repris par la Ressoucerie, entreprise d'intérêt public et d'insertion, créateur de design d'objet en upclycling.

La dépose du bloc clim et du ballon d'eau chaude est soignée, permettant leur revente par Synergie Péi. 

Building candidate in the category

Users’ Choice

Users’ Choice

Green Solutions Awards 2022-2023
 Circular Buildings Trophies 2022 building circular economy materials and solutions tertiary building Green Solutions Awards Green Solutions Awards 2022 2023

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clémentine thenot

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