• Building Type : Office building < 28m
  • Construction Year : 2014
  • Delivery year : 2015
  • Address 1 - street : 184 avenue de Londres 62138 DOUVRIN, France
  • Climate zone : [Cfb] Marine Mild Winter, warm summer, no dry season.

  • Net Floor Area : 250 m2
  • Construction/refurbishment cost : 570 000 €
  • Cost/m2 : 2280 €/m2

Proposed by :

Certifications :

  • Primary energy need :
    46 kWhep/
    (Calculation method : RT 2012 )
Energy consumption
Economical buildingBuilding
< 50A
51 à 90B
91 à 150C
151 à 230D
231 à 330E
331 à 450F
> 450G
Energy-intensive building

The operation involves the construction of an office building at Artois-Flandres Industries Park in Douvrin, London Avenue.

  • Plot area: 2000 m²
  • Building area: 250 m² (technical facilities and annexes included), 4 office for 2 people, a tearoom, a meeting room.
  • Cost of design-build contract: € 620,000 before tax. These costs include: fees, work and operating monitoring for a year.

Best Office Building: Some figures:

  • 18 monocrystalline 260 Wp panels; 4390 kWh / year expected for the overall needs of 3800 kWh / year (electro-domestic equipment included);
  • Bbio Bbiomax- = 25% (target - 30%)
  • RT = PV Cep out 46,3kWep / m².year) or Cep = Cepmax - 39% (target - 40%)
  • Cep total off Photovoltaics = 65kWep / m².year) (target: 120)
  • Cepenr = - 8kWep / m².year be Cepenr Cepmax = -110%

Internal consumption of electricity produced by photovoltaic panels to cover 100% of the building's electricity needs; Scalable building as will fit in the Third Industrial Revolution in terms of consumption, storage, industrial park in positive and zero carbon energy; Passive and positive energy building envelope according to the RT 2012 (Thermal régulation) ; Use of bio-sourced and made from recycled materials:

  • Bio-based materials: wood fiber insulation produced in France, OSB (oriented strand board) type panels of reconstituted wood (German origin), pine wood structure of the Vosges, interior and exterior cladding in raw untreated wood origin France.
  • Recycled materials: Wadded panels insulation (Métisse) (produced a few hundred meters from the building)
  • Health and Environmental Quality: domestic products eco-labeled (A +) , natural lighting, sun protection and automatic free-cooling following internal and external climatic conditions, etc. ;
  • Vegetated roof garden (50 cm vegetable substrate) to recreate the biodiversity of building' footprint;
  • Stormwater management: no possibility to infiltrate onsite given the vulnerability of the groundwater table. 3 levels of tamponade: the roof garden, rainwater collection tank (10 m3 for irrigation and flushing toilets) and a large capacity tight tank connected to the public network via a sludge;
  • Possibility of extending the construction above the parking (on stilts);
  • Measurement campaing of performance and comfort under way : transmit the experience, inform users and professionals.

Sustainable development approach of the project owner

Project REGAIN is an acronym in English of an European program. It can be translated into French by "Reduce Greenhouse Effect through Alternative Industrial Management of territories in North-West Europe"(
Research exemplary and demonstrator for the park industries
Innovation and anticipation of future regulations (Thermal regulation RT 2020)
Development of biodiversity (fauna inventory / current flora)
Development of bio-based and recycled materials (Manufacture of insulation Métis on the Park area )
Awareness of actors and students by opening sites (primary to +5 ) : schools sites, educational sites

Architectural description

Regain (Bis) is a lookout to bring man closer to nature. We were really surprised by the beauty of the site. Even if the Artois Flandres Industrial park is a place that has been recomposed by the hand of man, nature has nonetheless reasserted itself. We were touched by the “poetic” atmosphere; outstanding in a business area. In particular, the channel, the peaceful blue corridor inviting to travel; the wood planted on the nearby slopes, the island in ditches; twin slag heaps, tribute to the mining culture... We wanted immediately to build a panoramic viewpoint to place the visitor at the heart of this landscape. By elevating the building, it was possible to provide future occupants in constant contact with the environment.

On the ground floor, the visitor passes through a carpet of ferns and goes to the front door. A staircase then leads to the heart of the building, the large landing upstairs home serving all living spaces. Conceived as a nave-atrium with a glass roof, this area offers a 360 ° view: the sky and shrubs planted on the roof, as well as the surrounding landscape by transparency created through the offices. The living areas, offices and common rooms, surround this atrium, balanced and symmetrically, each benefiting from different directions and different landscapes.

On energy and the environment, we tried to reach the 15th target of high environmental quality (HQE), which tends to correct the ecological footprint ... In the case of a conventional construction; the influence of the buildings is permanently lost to the detriment of the biodiversity. We have therefore chosen to minimize the building impact on the ecosystem, restoring lost space: on stilts, the building will be covered with a roof garden.

REGAIN (bis) preserves of maximum the soil and recreates on the roof a “memorial" of biodiversity removed. We invite thus, biodiversity in both the building and under the building: shrubs, grasses, bulbs and plants on the roof, ferns under the building, recreating an image as the different strata of the forest environment, the undergrowth and the canopy.

Building users opinion

The employees of a company feel less invested with active mission to operate the bio climatisme of a building, therefore the automation of a number of function.
Bioclimatic design requires expertise to prevent disturbing effects such as glare or risk of overheating, particularly as the envelope is over-insulated.

If you had to do it again?

The Siziaf is an occasional contractor on building construction, this is not its original purpose.
The general organization of the project between architect and contractors as well as design and construction remains relatively much more complex when performance targets are expected.

See more details about this project




    Arnaud Lecourieux

    Site certified ISO 14001, Energy and Environmental Rehabilitation seat ongoing participation in European calls for projects to develop environmental practices in industrial activity areas

    Assistance to the Contracting Authority


    Assistance to the Contracting Authority

    Comète Ingénierie

    Yaminah Bellacene

    Assistance to the Contracting Authority




    Environmental consultancy


Contracting method

Other methods

Energy consumption

  • 46,00 kWhep/
  • 65,00 kWhep/
  • RT 2012

    Heating: 16.6 ECS: 0 lighting: 7.8 Auxiliary: 21.9

Real final energy consumption

    39,00 kWhef/

    11,90 kWhef/

    2 015

Envelope performance

  • 0,30 W.m-2.K-1
  • Bbio = Bbiomax - 25% (target - 30%)

  • 0,49
  • I4

  • 0,30
  • ongoing evaluations

More information

Cep RT = 46.3 Photovoltaic off kWep / m².year) or Cep = Cepmax - 39% (target - 40%) Total Cep out Photovoltaics = 65 kWep / m².year) (target: 120) Cepenr = - 8 kWep /m².an be Cepenr Cepmax = -110%


    • Individual gas boiler
    • Individual electric boiler
    • Others
    • Double flow heat exchanger
    • Solar photovoltaic
  • 100,00 %
  • 18 monocrystalline 260 Wp panels is 4390 kWh / year expected for the overall needs of 3800 kWh / year (including electro-domestic appliances)

    Apports solaires passifs, enveloppe sur-isolée (48 cm isolation périphérique, 40 cm en toiture et en plancher, triple vitrage)

Smart Building

    Energy metering, control of heating, lighting and cooling, raised defects

    Energy metering in real time (production and consumption)

    being evaluated

Biodiversity approach

  • 2 000,00 m2
  • 50,00 %
  • 1 725,00
  • Located on a ISO 14001 certified site, the building does not extend and remains compact. The majority of its grip surface on-high, reducing the footprint of the building, land and the deterioration of the existing biodiversity. The print is totally restored through the roof garden, allowing biodiversity reassert itself.
    The promontory creates thus a 360 ° view on the region and its remarkable sites.



    Le Relais

    Stéphane Bailly

    Métisse® is a range of acoustic and thermal insulation in recycled cotton for building construction. It insulates against cold and heat, but also the noise. It has exceptional acoustics thanks to the cotton that composes it. The RELAIS is a network of companies acting for 30 years for the integration of people suffering exclusion, through the creation of sustainable jobs. Member of Emmaus France, it based its action on the conviction that the return to work of people in difficulty is one way to help them preserve their dignity and regain a place in society. It developed for it several economic activities which have enabled the company to create more than 2400 jobs until today. The product is manufactured on the Park site a few hundred meters from the REGAIN BIS.

    Product greatly appreciated by companions because it is not irritating, easily hand cut, odorless during and after installation. It is also very easy to install , its acoustic and thermal qualities are felt in the premises in which it is placed .

Construction and exploitation costs

  • 12 850,00
  • 620 000

Energy bill

  • 14,00

Water management

  • 10,00 m3
  • Storm water recovery tank 10 m3 for:
    - watering: Drip drop enslaved to a humidity sensor
    - the flushing of toilets: Double speed chase

Indoor Air quality

    All interior products: (A +) certified or eco-labeled and current VOC measurement


    Natural cooling privileged Daylight View quality

    430 ppm (le 16/06/2015 à 16h)

    19°C mini et 25°C maxi

    24.1°C (le 16/06/2015 à 16h, température extérieure : 19.9°C)

    Inside dubbing Brown, in perforated vertical battens (in his trap)

GHG emissions

  • 4,80 KgCO2/m2/an
  • RT 2012

Life Cycle Analysis

    - Bio-based materials: wood fiber insulation produced in France, OSB type of reconstituted wood panels (German origin), pine wood structure of the Vosges, interior and exterior cladding in raw untreated wood origin France.
    - Materials from the Recycling: Mixed insulation panels and batting (produced on the park a few hundred meters from the building)

Reasons for participating in the competition(s)

​REGAINS BIS est un bâtiment exemplaire et innovant à plusieurs niveaux. Il est très performant énergétiquement (très faible consommation d'énergie par une enveloppe passive), il consomme 100% de l'énergie qu'il produit localement, il est composé de matériaux bio-sourcés et recyclés, et se préoccupe du confort et de la santé des ses occupants. Il respecte également la biodiversité du site qui est certifié ISO 14001 depuis 10 ans maintenant...Ce projet n'est pas né par hasard, il est le fruit d'une réflexion mûrie par l'expérience (cf. construction du premier REGAIN), mais également de la volonté de ses Maîtres d'ouvrage d'être exemplaire par l'action...

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