Can building passive can rhyme with competitive price?
On French passive projects, we are talking about additional costs or overinvestment compared to the BBC. In Belgium, where the concept is more widespread, the cost of building a passive building may be lower than that of a standard building. Explanations.
For its first collective housing project to target "passive" labeling, Habitat 62 / 59 Picardie will have spent more than for its previous BBC-Effinergie projects. An over-investment that should not prevent the company HLM nordiste to achieve its goal of producing 500 housing per year. Without a "very good price" land and regional subsidies, Denis Ratelade, construction manager, said he could not afford to meet the requirements of the German label Passivhaus on a program of 49 social housing.
The construction cost (excluding fees) of residential buildings under construction in Béthune (59) should be 1400 euros excluding tax per m². Either, according to Denis Ratelade, 200 euros more than a BBC project, or 400 euros compared to a building for no other purpose than compliance with the RT 2005.
This over-investment seems to be concentrated on a few lines of price slips. For example, triple glazed joinery accounts for almost 15% of the construction cost. The project's actors also point out the cost of the dual flow VMC with exchanger, equipment that could be done on a BBC, but which is essential for any building that claims to be passive. Installed in each of the housing units, each unitary system returns, on this building site, to close to 5000 euros.
In France, the requirement of "Passive" requires expensive equipment and can be expensive for craftsmen.
The importance of the cost of glazing and VMC double flux are also found on a passive project located in Champagne-Ardenne. The Foyer Rémois, whose homes built in 2011 are at least BBC, had shown the way to the northerners, delivering, in the spring 2010, "La Clairière". The construction of this building 13 passive housing, located in Betheny, near Reims, will also have to wipe plaster casts.
Development director of the manufacturer of Champagne-Ardenne, Jean-Denis Mège warns owners and businesses: the level of detail required for passive labeling is higher than for a BBC and therefore requires increased concentration during production.
"The" La Clairière "site lasted 20 months. Faced with the zeal of the Passivhaus Institut certifiers, the site's companions had to review their copy and some had to redo the work several times to achieve the required quality of execution. Extending the time spent on the site can be costly for subcontractors, ”explains the person who supervised the work.
Windows to replace, VMC to recoffrer, Canadian well ventilator to resize ... the list of the problems met on the site did not demotivé Jean-Denis Mège. On the contrary, based on its experience, the latter considers that by rationalizing future passive projects should not require an overinvestment of more than 10% (compared to a low-energy project).
"Passive construction requires expanding the mission of the thermal engineer, meticulously observing the execution details or even verifying the material certificates", explains the development director of Foyer Rémois. "But this rigor makes it possible to obtain a building whose real performance matches theoretical performance," he explains. And that is priceless.
In Belgium, prefabrication reduces construction time and makes the "Passive" more than competitive
Beyond the Quiévrain, the concept of "passive" is much more widespread. In the Brussels region, where building to passive standards will be mandatory for all buildings from January 1 January 2015er, there is already more 300 000 m² meeting the requirements of the German label. Here, we no longer speak of overcost or overinvestment linked to the "Passive" label. The Brussels architect Sebastian Moreno Vacca won a competition for the construction of a set of 50 housing, a school and some offices, proposing a construction cost to 1100 euros per m², 15% less than the average cost of other unsuccessful projects.
The secret: reducing construction time thanks to extensive prefabrication. "In Belgium, pouring concrete is a luxury. On our project, the facades consist only of 5 different prefabricated modules with which we play to vary the appearance of the buildings", explains the architect in charge of the house platform. passive of the flat country.
Sébastian Moreno Vacca also emphasizes that responding to design-construction calls for tenders allows "working hand in hand with companies to implement a whole bunch of little tips". "For example, for electrical outlets, rather than using more expensive airtight plugs, we use standard plugs behind which we throw plaster, a material that is found in abundance on construction sites."
The price of materials can also explain that building passive in Belgium does not necessarily cost more. Sébastian Moreno Vacca does not hesitate to install triple glazing on all the facades of his projects. "Now you can find them for less than 300 euros per m²". The Belgian architect tried to get the same price on a French project, he says he was "rebuffed".
In short, to make that French side, passive rhymes with competitive, it will not only be enough to change the habits of site.
Eric Leysens | Source THE MONITOR.FR
Source: http://www.lemoniteur.fr/195-batiment/a ... competitif