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 €
  • 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

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. The approach of reuse. The opportunity is perfect: a small scale, perfect for experimenting with the practice, and a project management team 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 the 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 La 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 by 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 access to 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



    Ordre des architectes Réunion Mayotte


Construction Manager


    Marine Martineau, martineau[a]co-architecte.com


    Other consultancy agency



    Structural design office

    Environmental consultancy











    Rehabilitation / Structural work




    Green spaces

Contracting method

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

    The project was designed with natural ventilation, taking advantage of the thermal breezes crossing the territory. The largely porous facades allow the passage of air and the feeling of a reduced temperature.
    This system is complemented by effective solar protection.
    In addition, the West and East facades are designed as opaque gables, thus limiting overheating linked to sunshine (in La Reunion, it is these facades that must be protected as much as possible). The north and south facades benefit from large openings protected by horizontal sunshades completed on the south by solar protection cheeks.


    Passive cooling solution: natural ventilation

    Gros œuvre / Système passif

    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 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

    Gros œuvre / Système passif

    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


    Génie climatique, électricité / Ventilation, rafraîchissement

    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).

Urban environment

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 are still there.

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.

Land plot area

328,00 m2

Built-up area

27,00 %

Green space


Parking spaces

2 parking spaces including 1 for disabled people.
1 path accessible from the parking area allows bicycles to be parked at the back of the plot.

Building Environmental Quality

  • indoor air quality and health
  • works (including waste management)
  • waste management (related to activity)
  • energy efficiency
  • products and materials

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.

Sustainable design

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

    These wooden slats come from the Pont de la Rivière de l'est, an emblematic construction of the Reunionese landscape. S2R being in charge of asbestos removal from this bridge, we were easily put in touch with the contacts, including Freyssinet, in charge of the rehabilitation of this bridge. To avoid waste falling into the overhanging river, the disposal protocol plays in our favour. The wooden strips will be cut along the lines of the fixing nails.

    We had agreed with the company EBOI in charge of the installation, that it will not have to carry out any intervention on these blades, so as not to risk damaging their machines. It is therefore a bit of a "bet" to reuse these blades as they are. In this sense, their exposure to rain and salinity testifies to the great resistance of these elements, sized for the passage of vehicles. We will use them in interior parquet, their use is therefore "downgraded" and thus guarantees the durability of these boards.

    Exterior joinery / 4-pane wooden frame windows: 4 units - Joinery from the demolition of the Gîte du Volcan (Réunion), reused

    These woodwork are the only materials deposited by a company external to the group, EGB Zilmia. We had been invited by the architects to offer us the materials from the demolition of this gîte, for which we carried out a reuse diagnosis. However, once a large number of materials were targeted, the lodger recovered a good part of the available stocks and the company had on its side, arrangements with local farmers to take back some of the materials. We were only able to recover these joineries, after much insistence. This experience led us to ask more questions about the internal arrangements and organizations of construction sites, especially when we arrive at the end of the chain to recover materials.

    However, the game is worth the candle. Once sanded and repainted, these woodwork still hold up well and are also witness to an emblematic architectural heritage of Reunion.

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

    The floor coverings have been the subject of meticulous work and research by the Ad'hoc landscaper. In the same dynamic as that of the building, the existing floor coverings were carefully removed (facilitated by their laying on a bed of sand) in order to be reused as a pavement, in the form of a callade. Asphalt slabs will complete this plant patchwork, the joints of which will be grassed. In appendices, a plan for identifying the landscape intentions for these coatings.

    The raising of this box has been designed in a wooden structure in order to allow its complete dismantling. This structure was sized from sections of wood from scrap stock available from the company EBOI, holder of the lot.

    The free plan of this floor, lit and naturally ventilated, will also allow a new compartmentalization of space in a future use.

    The concrete box has been preserved as much as possible, hardly touching the initial partitions, in order to limit the quantities of waste generated as well as the use of new materials.

    The elements that could not be reused were made of Cryptomeria wood, a local wood from Reunion still too little used in construction. We seek by this to demonstrate the possibilities of this material and to promote its use.

    Similarly, in order to preserve the existing structure of the hut, reinforcement operations have been implemented. Links of beams - slabs as well as carbon reinforcements were made to allow the raising.

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 panes: 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.


Reproductibility and Innovation

    The project, as we have explained, was, from the competition phase, presented from the angle of reuse. We therefore had great support from the MOA, which supported us in this process. A rental lease has been signed pending the delivery of the official keys to allow us to store the materials used. In addition, the choice of the technical controller fell on a professional who was open and helpful with regard to the regulatory obstacles that may be encountered. He agreed to limit his missions to structure and accessibility, which allows us, among other things, not to present technical data sheets or AEV characteristics to reused joinery.

    The materials were sourced throughout the design before being integrated and described in the market file. Not being subject to a public call for tenders, and having been largely supported and supplied with materials by the companies S2R and EBOI, we therefore offered them to officially join the adventure.

    In the written documents, the reuse elements were described in the corresponding batch, and not in a separate batch. It was quantified for each, the services expected (refurbishment, sanding, cutting), specifying whether it was a question of supply or installation. The origin of the deposit was also specified in the CDPGF. The operations were then precisely described in the CCTP. The preamble of the latter presented the challenges of reuse, and insisted on the need to favor reused resources rather than new ones.

    Finally, a specific reuse notebook listed all sourced materials, in the form of traceability sheets to allow a visual and complete monitoring of resources.

    The storage of materials was allowed on site, thanks to the temporary lease signed by the MOA, in particular for materials deposited by companies outside the project (such as EGB Zilmia). In this case, we signed an estimate for the transport from the Gîte du Volcan to our site with the company in charge of the removal (EGB Zilmia). We also benefited from storage with Synergie Péi, which organizes "Materials flea market", supplied among other things by S2R, and from whom we had selected joinery that they were kind enough to store for us until the start of the works. The roof was stored by the carrier mandated by S2R to evacuate it. The scrap wood was already present in the premises of the carpenters who kept it until the manufacturing stages.

    The main obstacles were to be able to ensure the availability of the materials, on the one hand before other actors just as legitimate as us decide to recover them, and on the other hand in the management of the schedule. It was a question of anticipating a removal not too early to avoid storage, nor too late, which had a heavy impact on the site. We were obliged to make forecasts on a certain number of materials, and to sometimes go back when they were finally no longer available.

    Finally, we wrote "Matières Péi" editorials throughout the design and the project in order to share and communicate around the approach. It is also an opportunity to promote the actors who have intervened in the project and who have accompanied us in the process.

    The company in charge of structural work and demolition, S2R, ensured continuity and exchanges between these demolition / cleaning / construction phases.

    The existing floor coverings have been carefully removed in order to provide for their reuse.

    In addition, 2 small lean-tos were present on the plot. Their deconstruction generated rubble that will serve as backfill for the slope for PMR accessibility. The square tubes making up their metal frame were recovered by the Ressourcerie, which is in charge of creating 2 offices and a meeting table by upcycling. It offers furniture incorporating square tubes and melamine tops, all made from reused materials.

    The circle is complete!

    The materials resulting from the deconstruction and targeted by a reuse operation were stored on site. The square tubes were evacuated during construction to be deposited with the lessee, a donation to the Ressourcerie.

    The technical equipment (hot water tanks, air conditioning) was recovered by workers on site or offered at the Synergie Péi materials flea market, in the form of a donation.

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)

This project is the very first reuse project on Reunion Island. Accompanied by the companies in charge of the project (EBOI, S2R and Paysages), the architects got down to sourcing the materials and supplying the design in parallel. Many round trips were necessary to finalize the project.

The facades of the elevation will be made up of joinery from the deconstruction of the Gîte du Volcan and the Sainte Thérèse Maternity Hospital. The sheet metal roof comes from the elevation of the Maternity Sainte Clothilde, the wooden floor is made of the decking of the Pont de la Rivière de l'Est. The brises soleils use recycled and treated pallet wood. Sanitary equipment is also reused.

We also use stock scraps. Thus, the frame was drawn from a stock of wood from the company holding the EBOI lot. The tiling comes from surplus S2R sites.

In the context of on-site demolitions (small lean-tos and floor coverings), the latter will be used as embankments to allow PMR accessibility, and as exterior floor coverings.

The metal tubes supporting the small roofs were taken over by Ressoucerie, a public interest and integration company, creator of upclycling object design.

The removal of the air conditioning unit and the hot water tank is neat, allowing their resale by Synergie Péi.

Building candidate in the category

Bâtiments tertiaires / prix de la rénovation

Bâtiments tertiaires / prix de la rénovation

Trophées Bâtiments Circulaires 2022

 2022 Circular Buildings Trophies
 circular economy
 materials and solutions
 tertiary building

Author of the page

  • Clémentine Thenot

    Chargée de projet environnemental


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    Trophées Bâtiments Circulaires 2022