The rehabilitation of the building 2 Rue Rabelais in Montreuil is part of a High Environmental Quality. Generally this approach is designed to meet the traditional quality objectives (architectural quality, quality of use, quality of atmosphere, technical grade) while limiting the environmental and health impact of the building.
The project we have reached today with href=”http://www.lepissier-architecture.com/” architect Pascal Lepissier meets our ambitions for its specificities both architectural and technical. The following is a brief description of the project and a presentation of thematic issues addressed by the Building winner strong> of the call for Sustainable Rehabilitation project.
As an environmental consulting firm, we tried to make our future headquarters showcase our skills in the field of environmental consulting in the building. In partnership with our architects, so we tried to define from the constraints of the site and its opportunities, the best response to the new challenges of construction, namely:
– Bioclimatic design
– Limiting the building’s carbon footprint
– Limitation of drinking water needs
– Reduction of waterproofing rate Plot
– Visual comfort
– Hygrothermal comfort
– Choice of building materials according to their environmental and health quality strong>
Although the project includes a renovation phase of the existing building, we wanted the whole building is well outperforms the objectives of the RT 2012. Strong>
We then during design studies sought to go to that level of performance in seeking to limit the heating needs below 10kWh / m² strong> and compensating all regulations in energy consumption primary by a local production of electricity from photovoltaic solar panel of 21.8 kWp. Strong>
So today the building is energy positive with a production of 48.6 kWhep / m².year strong>
Réponse architecturale :
• North and South facades largely glazed strong> to ensure visual comfort throughout the depth of the office floors
• South façade is protected from solar gain summer via caps on each level and external fabric blinds but leaves fully enter winter solar gain in order to reduce heating needs
• North façade is equipped with interior blinds strong> to reduce the number of hours of overheating and ensure visual comfort.
And • ventilation windows are installed in the upper part of the two opposing fronts to promote natural cross ventilation strong> and enable naturally ventilate or surventiler strong> trays according periods year
• insulation of wood frame walls with a double cross-layer insulation strong> so as to cover the amounts of the framework and ensure an insulating jacket without breaking
• Special attention was also paid to the air tightness of the building strong> with a rigorous design and site supervision at the level of singular points with validation of performance achieved by a test the end of the open and closed just before the
Spaces organisation :
• The existing post beam structure allows to benefit from vast plateaus of 10 m deep. Unlike existing offices we have chosen not to retain the partitions in individual offices to take advantage of these large trays widely naturally lit strong> throughout their depth.
• This solution also advantageously benefit from the effects of cross ventilation strong> to ensure summer comfort passively strong>.
• The low value added areas that are the elevator, reprographics area or health were all grouped on the facades North and East in order to benefit offices and the best orientation meeting room in the South.
Materials choice :
• We are committed to selecting materials healthy strong> and low emission of pollutants strong> for the interior spaces arrangement. As such the walls are painted with paints enjoying their labels or certifications regarding VOC emissions to air, type Blue Angel, White Swan or NF environment.
• For flooring, there is a ground cast rubber also benefiting certificate on VOC emissions. This type of seamless smooth coating is easy to clean and does not require specific products that emit odors. Also pouring through the delivery system avoids the use of adhesives often emit odors and VOC also.
• Apart from a few acoustic panels, there is no false ceiling in the building. The chosen acoustic solution also complies with the European Directive 97/69 / EC of 5/12/97 on the carcinogenicity testing mineral fibers. These are also bagged to avoid the risk of polluting the air inside.
• In addition to the aspects related to health quality, the materials also have an impact on the embodied energy content in the building. One of the big interests of the rehabilitation strong> is to limit the consumption of resources and energy to the new building since some existing elements are retained. On this, it is the whole of the steel beam structure poles + concrete slabs and brick gable was kept. In addition, the inventory of existing allowed to list a number of facilities that have been preserved during the demolition for reuse in the new building as:
• Insulation acoustic partitions
• some health facilities in good condition (toilet bowls + sinks, taps …)
• various electrical equipment,
• certain doors
• Fire extinguishers
• The Recovery strong> of the good quality materials already present in the existing building has a small financial economy strong> on the project while having a favorable impact on the amount gray expended energy strong> for building rehabilitation. For new materials of the project as the facade, insulation or coating materials we selected the products for their ability to be recycled strong>, their natural strong> or < strong> local production strong> and under accession suppliers and companies to the HEQ strong>.
• The supporting structure of the existing building is steel beam columns and concrete floor. One of the benefits of rehabilitation is to benefit from this existing structure in good enough condition to ensure the same role for the next 50 years of life of the rehabilitated building.
• The project rehabilitated to permit adding 2 additional levels strong> from the existing building. These 2 levels that will be added to the existing framework will also respond to a light structure.
• The north and south facades reported the slab edge are also wood frame and insulated by two crossed layers of wood fiber. Pinions brick which were stored are in turn isolated from the inside and also by a wood fiber. Wishing to avoid thermal bridges at the posts found in nuts, we have chosen to encoffrer in the thermal lining. These posts are 220 mm deep so we could use a less efficient than glass wool but thicker insulation.
• For all the wooden elements, the CCTP demanded that the wood comes from sustainably managed forests strong>, provide the origin of the wood and emphasize local wood strong> to France and finally to select the timber in use class to avoid treatments.
Réponse technique :
• The heating is by radiators and hot water via a gas condensing boiler strong> associated with inter-seasonal heat storage system strong>.
We actually opted to install an inter-seasonal heat storage innovative system whose operation is as follows:
hot water storage at 90 ° C occurred during the summer
– By 2 thermal solar tubes 3m strong> each installed south facade
– 1 storage tank with a total volume of 10m3 strong> very highly insulated (polyurethane 50cm).
This hot water is then used from the start of the heating season to warm the return of the hot water distribution circuit (after passing through the radiator) to limit the power drawn via the gas boiler. According to our theoretical studies, this solution is one that allows the best exploitation of the volume of hot water since it allows a saving of 900 kWh per year or 9% of needs.
• The ventilation of rooms is by double flow system efficiency plate heat exchanger 90% strong> and driving speeds by time control associated with a presence detection at each blowing opening strong> to adjust the flow rates to the occupation of each plate and limit electricity consumption ATK fans and winter heating needs.
• A rainwater recovery tank strong> for the building of health food. Studies show that a coverage rate of about 80% is achieved via this 8m3 vessel.
• Installation of 21.8 kWp photovoltaic panels strong> ensuring the roof terrace pergola role compensates for primary energy consumption of 5 and regulatory positions and to reach the level passive building.
• We considered the use of a PAC Geothermal given the presence of water in the basement, however the hydrogeological feasibility studies we realize showed that the exploitable water table was at a depth 60m and therefore costs drilling would not be recouped over the life of the light installation of lower building heating requirements.
• DHW heating is by electric balloon. A comparative study of different solutions was conducted and shows that decentralized Joule solution is the most interesting both from the perspective of the primary energy consumption and the financial point of view. Note also that only the showers and the cafeteria will be supplied with hot water, sanitary floors are supplied in cold water.
• Artificial lighting by low consumption T5 luminaire for offices and LED boards in the meeting rooms. Lighting is controlled by brightness sensor strong> to adjust the lighting power needs.
• Installation of Many sensors strong> (temperature probe, air velocity, …) connected to a BMS strong> to make a follow-end performance and building dynamics . This tracking allows us to always make the most passive solutions strong> installed on the project ie the natural ventilation, heating via the inter seasonal heat storage facility. BMS is also connected to many energy meters allowing us detailed analysis of consumption of each position strong> (lighting, auxiliary heating and ventilation, computer equipment, hot water, heating offices , preheat the fresh air, …)