The Grenelle 1 Law, passed in June 2009, sets ambitious targets for energy efficiency in buildings: dividing by 4 emissions of greenhouse gases by 2050, a 23% share of renewables in end consumption by 2020 and the establishment of the Building Plan. Representing 40% of the total energy consumed in the European Union and 46% in France, the building stock is a key instrument in energy saving policies.
The building plan: reducing energy consumption and greenhouse gas emissions
The Building Plan‘s target is for a 38% reduction of energy consumption and 50% of greenhouse gas emissions by 2020 in the building sector. These targets are based in part on a regulatory policy applied to new buildings. In 2012, all new buildings will comply with the BBC Low Energy label (Low Energy Building): according to RT 2012 (Thermal Regulations), they must use less than 50 kWh/m² per year, compared with 150 kWh/m² per year for the 2005 thermal regulations. 400,000 housing units per year will be renovated starting in 2013, and 800,000 of the most energy-hungry social housing units by 2020. The energy renovation of all buildings belonging to the State and its public buildings will be started by 2011. In 2020, all new buildings should be positive energy buildings, i.e. producing more energy than they use.
Three steps to achieve Positive Energy Buildings
In the Building Plan’s objectives, three steps are proposed. After the widespread construction of buildings according to RT 2012, the goal is to pass onto “passive houses”, whose energy consumption is very low, and which exist in significant numbers already in Germany and Switzerland. In 2020, all newly built houses will have to meet the positive energy requirements. They will use no more than a very small amount of fossil fuel, producing their heat through heat pump systems or solar thermal electricity and will obtain the electricity needed to operate the building using equipment using renewable energies.
The approach of a progressive reduction of energy consumption in the building sector. The final requirement of positive energy houses for a significant production of renewable electricity, of which a small part at least will be fed back into the grid, will require several prerequisites. First, the building will have to have a sizable amount of production facilities, allowing it to be supplied by several renewable energy sources for generating electricity and operating the thermodynamic devices (such as heat pumps). Then, it will have to record excellent performances in terms of thermal insulation. Finally, all the building’s electrical functions will have exemplary frugality and will be controlled. Failing this, the balance between the energy produced and the energy consumed will remain negative.
This house of the future could, ideally, be autonomous in terms of its electricity supply. This is the case of Abalone Energie ‘s headquarters, the first autonomous European building with no release of greenhouse gas emissions. However, currently, most positive energy buildings built are not fully autonomous, and remain, especially during the winter period, dependent on a backup electricity supply.
Read more :