Le show forum wood of Marvejols BBC has a wooden house in Lozere
The first BBC labeled wood house in Lozère qualified as "the most waterproof house in France" (BBC: Low Consumption Building)
In February 2010, the company ORLHAC sarl built the first wooden house in Lozere labeled BBC (House Lagloire to Montrodat) according to the plans of architect Nathalie Crepin. The results of the blower door test (Q4 = 0,07) for the labeling of the building, have a much better performance than necessary to label BBC (Q4 = 0,60) and even to those of the label LIABILITIES (Q4 = 0,20).
Tests passed hands down, this house was called wood "most waterproof house in France ..." by SIRTEME certifying body. The Grenelle 2 law, published in the official journal 13 July 2010, aims to improve the energy efficiency of buildings and harmonize planning tools.
In view of this publication, this construction built in February was very avant-garde because of the new regulations and test scores.
Questions to Jean-Pierre Orlhac, manufacturer and Nathalie Crépin, architect
CCI: Can you clarify what a BBC home?
JPO: It is a low energy house. The designation BBC Effinergie is an energy performance label constructions. It refers to new buildings whose very low energy requirements (for heating, hot water, ventilation, ...) can significantly reduce fuel consumption and thus the cost of running the house, but also its gas emissions Greenhouse effect.
NC: A BBC home has every interest to meet the criteria of a bioclimatic building to take full advantage of environmental inputs before calling technology (solar photovoltaic, solar thermal, heating system ...). Bioclimatism allows use from the design of a house, the advantages of the microclimate of the implantation site (sunshine, prevailing winds, soil inertia ...) without neglecting the human side of the project, that is -dire functionality and comfort. A bioclimatic house must strive for energy independence through a symbiosis with the natural environment.
CCI: What are the difficulties in the implementation of this type of work? and what a blower door test?
JPO: To achieve an efficient and economical home from an energy point of view, healthy and comfortable for its occupants and at an acceptable cost, it is necessary to adopt a comprehensive approach from the design of the house.
It will in particular ensure the compactness of the house, its orientation, the level of insulation of walls and woodwork, the airtightness at the choice of ventilation and heating system.
Obtaining the BBC Effinergie Label requires a very high level of insulation, but it also incorporates an imperative parameter control of the airtightness of the walls. This is to eradicate parasites cold air intakes, which may represent 25% of heat loss of traditional buildings (cold air entered by decision, on the perimeter of the openings through the roof ...).
The infiltrometry test is designed to measure these leaks and parasitic air penetrations. For this, we install a "fan door" and pressure sensors connected to a computer control measures. The building is pressurized and depressed to simulate the effect of wind on the outer walls and thus measure the rate of air exchange by leaks. This test was carried out during the construction phase (self-checking phase) and at the end of the construction site to verify that the house meets the requirements of the BBC-Effinergie label.
The results of the infiltrometry test are excellent (9 times better than the requirements of the BBC label, 3 times better than the PASSIVE HOUSE label) and confirm the performance of the wood frame wall "Low Energy ORLHAC" developed by our office. internal studies, manufactured and implemented by the ORLHAC carpentry team.
ICC: What are the challenges in the design of this type of project?
NC: The labeling of a BBC building is obtained after tests and mainly thermal and energy studies. The difficulty in designing this type of building is that thermal requirements should not take precedence over all the parameters related to the project design: functionality, integration to the site, comfort of life, and costs ... The draft Mr. and Mrs. Lagloire is as such a success because no concession aesthetic and functional (eg accessibility) was made at the expense of its thermal performance.
CCI: Is the wood a particularly suitable material for designing houses BBC?
JPO: That's exactly right. timber construction, well designed and well controlled, is well positioned to meet the thermal performance requirements and control construction costs. Wood is also a natural, renewable and clean, which has a beneficial effect on the potential for global warming: it can store a large amount of carbon; between 20 and 30 tons for a detached house.
NC: The benefits of designing a BBC house wood frame are multiple. This offers more freedom for the integration of windows or bioclimatic greenhouses. The timber also facilitates the junctions between the vertical walls, the horizontal walls and openings. The building gains in coherence and thereby the thermal bridges and air are reduced. Thanks to prefabrication of timber frame, the on-site assembly of duration is fast and risk approximation diminished.
CCI: An accepted idea is that wood buildings have a shorter life span than so-called "traditional" buildings (concrete, bricks, stone ...). What do you think ?
JPO: There are no particular problems on the durability of wood constructions. There are numerous examples in France and abroad. Here, one of the oldest houses in Saint Chely d'Apcher, home of Miss BONNET, is a timbered house with wooden support structure ... Of course, as with all construction materials, wood requires a good design and know-how of implementation.
NC: This misconception is understandable, here in Lozère, because historically the building material was stone. In areas (eg Alsace) or countries (eg Sweden) in which the buildings were constructed of wood, this preconceived idea does not exist. We find buildings with centuries-built timber (forerunner of the wooden frame), or adobe houses.
CCI: Do you think it is possible and profitable to design buildings BBC to higher dimensions (semi-apartment buildings, kindergartens, schools, ...)?
JPO: Of course. The search for thermal performance, control of operating and heating costs, well-being of the occupants and respect for the environment is equally present in the collective buildings. The large BBC buildings appear here and there: social housing, schools, nurseries, administrative buildings. In 2009, we participated in the construction of an 350 m2 "passive" administrative building: although it is located in an unfavorable climatic zone, this building does not need a traditional heating system or air conditioning.
NC: As the building is large easier it is to design the BBC because the more you can make the compact building, the more decreases the surface of the outer walls and thus the sources of losses. Today I work for example in the design of a timber housing in Ispagnac, which is common to several families. The association of the buildings there allows a reduction in energy costs.
CCI: What is the future of the wooden house and the BBC in Lozere?
JPO: Environmental issues, energy management and regulatory developments lead us to prefer low energy consumption buildings. To achieve this, the wood will remain a reliable, comfortable, economical and respectful of our environment.
NC: After this experience, I direct all my sites to test the seal because it provides a guarantee to the quality of implementation. More companies are likely to experience the BBC over this implementation mindful of detail will become obvious.
Moreover, the Lozère is the department with the lowest average temperature, the heating-related energy expenditure is important, the return on investment is very fast. This should logically be very incentive for developing BBC Lozère.
Questions to Mr. and Mrs. Lagloire, project promoters
ICC: Why and how did you get the urge to build this type of home?
SL: Initially, we did not know the concept of the BBC, we wanted a bioclimatic house and integrated into our build environment (semi urban Caussenard atmosphere). So we appealed to Nathalie CREPIN was sensitized bioclimatism. She designed the house on these principles plus an accessibility constraint for a person in a wheelchair. On this basis, we filed a building permit on February 6 2010 and obtained two months later. At this point, we still do not have a notion of the BBC.
Later, during a discussion with Mathieu COUDERC, in charge of the Department of renewable energy, we discovered the BBC and its financial benefits (energy savings and tax benefits).
Soon, we sought information and local artisans to adapt our project with BBC requirements. We met with the company ORLHAC who worked on wooden houses with high energy performance. The seriousness and motivation of this business we decided to embark on the adventure of the BBC. So we gathered all the companies with which we planned to work and we presented them our project and BBC as no craftsman had no experience in this area, we asked them if they agreed to play the game and they all accepted. We wish also to thank again because they were great in the quality of their work.
ICC: Why wood? Is it easy to carry a wooden house project in Lozere?
SL: My parents have a wood frame house came directly from Germany for thirty years and it is built, it is still comfortable and reasonably consuming energy. Looking at the design of this house, we saw that the Germans were well ahead in wood construction.
CCI: How long took place from the project idea to the layout in your house?
SL: The idea of the strict consensus BBC project emerged the 13 2009 April when we met with Mathieu Couderc (the permit was already obtained), and we moved the 26 August.
CCI: Are there additional costs in this project compared to a house called "classic"? Is it compensated and how?
SL: Basically, we had a house with an original design (greenhouse arched), specific equipment (Canadian well, comfort ventilation, solar thermal, solar photovoltaic, breezes sun), we used still little used materials by artisans (wood wool, fermacell, tiles larch) which increases the cost compared to a conventional actual construction, but it was a personal choice.
The cost of the house is estimated at 1 600 € TTC / m2.
With experience, we have learned that we can still make the BBC a more modest cost. We believe the BBC, it is mostly a reflection (often common sense) on the orientation of the house, insulation, choice of materials and electrical equipment (including ventilation) and most of all excellent quality of implementation on tightness parasite air and on the latter point, the company ORLHAC brilliantly showed that she was very competent.
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