ENERGY EFFICIENCY

Doing more with less

The most direct weapon for combating Europe’s dependency on hydrocarbon imports can be summed up in just two words: energy efficiency. The energy-thirsty construction sector in particular offers major scope for savings.

© CNRS/Photothèque/François Penot
© CNRS/Photothèque/François Penot
© Shutterstock
© Shutterstock
Comment rendre les bâtiments peu énergivores? En isolant, en optant pour le bois ou les panneaux solaires. La «flamme bleue» (Laboratoire d’Études thermiques – CNRS) est une visualisation des mouvements d’air internes contribuant à la compréhension des turbulences pour maîtriser les transferts de chaleur en minimisant la consommation énergétique. © Shutterstock
How to make buildings less energy thirsty? By insulating, opting for wood or solar panels. The “blue flame” (Laboratoire d’Études Thermiques – CNRS) is a visualisation of internal air movements as an aid to an understanding of turbulence to control heat transfer while minimising energy consumption. © Shutterstock
Maison des Cyclistes à Ixelles (Bruxelles – BE). Ossature en bois FSC (Forest Stewardship Council), panneaux solaires thermiques, géothermie, double vitrage et isolation, éco-matériaux, toiture végétale. © Jean-Paul Hermant
Maison des Cyclistes à Ixelles (Bruxelles – BE). Frame in FSC (Forest Stewardship Council)-certified wood, thermal solar panels, geothermics, double glazing and insulation, eco-materials, vegetal roof. © Jean-Paul Hermant
© Shutterstock
© Shutterstock

Consume better to consume less: that is Europe’s new motto. As it tackles three key sectors – transport, industry and construction – it aims to reduce energy consumption by 20 % by 2020. The European Commission’s “Action plan for energy efficiency” identifies the construction sector as top priority, with it alone absorbing about 40% of the EU’s energy. Housing accounts for about two-thirds of this percentage, with public buildings and business premises making up the rest.

What is more, for once this is a field in which private interests are largely favourable to public initiatives. “Unlike other sectors, and transport in particular, introducing energyefficiency measures to buildings brings only benefits, in terms of reduced energy bills, increased comfort and job creation,” stresses the European Construction Industry Federation in a memorandum(1).

Act locally, think globally

The eco-design of a building offers a twofold advantage. First, from an economic point of view it results in huge energy savings. “We can divide a building’s energy consumption by eight and thus reduce consumption from 280 kW/h/m² to 35 or even 15 kW/h/m²,” explains Claude Rener, Administrator with Arc&Style, a Belgian company that has specialised in eco-construction and eco-renovation for the past 25 years. Secondly, from an ecological point of view eco-construction concentrates on the global energy balance of a material and thus takes into account the energy used in its production as well as the energy savings it will permit when incorporated in a building. “We take into account the total impact of the material on the environment, from its creation to its destruction. It is an approach that also opens up a whole new recycling chain based on the recovery of grey energy (2) from materials,” continues Rener.

Wood is particularly favoured in this new vision of construction. “This carbon reservoir can be used both as the frame and as insulation, in the form of wood fibre for example.

It makes it possible to obtain a very low K coefficient (3), and thus to limit heat loss from the building. To offset wood’s low thermal mass – its ability to store heat – it is combined with silico-calcareous materials that are less demanding on energy than earthenware bricks and better calibrated, which makes it possible to limit mortar use. Admittedly these bricks are a little less effective in terms of insulation but when reinforced with wood insulating sheets the energy results are nevertheless excellent.” This innovative approach also marks a return to the materials of the past. “Traditionally, wood has been favoured in the construction sector.

Similarly, natural, earth-based coatings, straw, air-slaked lime, marble or casein powder are making a marked comeback after having been abandoned during the past 30 years or so,” notes Rener. “When combined with modern methods – such as domotics that make it possible to automate a building, or heat pumps that will soon replace condensing boilers – these traditional materials help save vast amounts of energy.” The biggest challenge of course lies in renovating existing buildings, which are the most numerous and the least efficient. “All the technologies needed have already been developed and the issue now is to discover how to speed up their inclusion in everyday life,” explains Andrew Warren, Adviser with the European Alliance of Companies for Energy Efficiency in Buildings (EuroAce). This is the goal of the European Energy Performance of Buildings Directive (EPDB), which entered into force in 2003 and introduces requirements in terms of the energy certification of buildings, a joint evaluation methodology, minimum performances for certain buildings and the training of experts to make regular inspections.

The inaction of Member States

By adopting such measures Europe would already be able to reduce its energy consumption by 11%. Yet despite such promising potential, the Member States seem torn between the political commitments given at European level and the actual implementation of the measures laid down in the EPDB. At the end of February 2007, infringement procedures were instigated against 19 countries that had failed to submit an action plan setting out national measures acting on the Directive. “It was negotiated by the energy ministers but has to be applied at national level by the construction and buildings ministers, hence the problem of synchronisation certainly explains this delay on the part of Member States,” says Andrew Warren. “This situation is further aggravated by the fact that building policy is fragmented inside the Member States themselves, with responsibility lying at regional level. Also, only new buildings and buildings of more than 1 000 m² that undergo major ren- ovation are subject to energy performance obligations. The present shortage of experts is also delaying the system of certification that is supposed to draw up an inventory and identify actions to be taken for each building owner.

It must also be said that this is the first energy efficiency measure to really tackle buildings globally so it is perhaps not surprising that implementation is taking rather long.” “Fortunately,” says Claude Rener, “whereas we were preaching in the desert for 20 years, we have now seen a major shift in public thinking since 2000, and also among politicians who – at least in Belgium, the Netherlands, France and Germany – are making strenuous efforts to put into place financial incentives.”

Julie Van Rossom

  1. FIEC Memorandum, The impact of buildings on climate hange - FIEC’s suggestions for raising the energy
    performance of buildings, 6/12/2007.
  2. The quantity of energy needed for the production of industrial materials or products.
  3. Heat insulation coefficient of a material constituting a wall or a building (not to be confused with the lambda) – the lower the figure the better the insulating performance.

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Some European projects

What to do while waiting for Member States to transpose European resolutions? Intelligent energy for Europe, a vast programme launched in 2003 and now financed under the Framework Programme for Competition and Innovation, already supports many projects designed to promote the development of green energies and improve energy efficiency.

  1. EuroTopten is a website where you can compare the energy efficiency of various products available on the market. It consists of 10 sites for 10 Member States (FR, AT, BE, HO, IT, PO, HE, NL, FI, CZ).
  2. The ECO N’HOME project offers 1 000 European households a free energy audit of their home and travel practices. The data obtained are then used to draw up a guide to best practice in this field.
  3. BOILEFF aims to optimise the use of boilers and water heaters. Responsible for most of the energy consumed in European buildings, these appliances are often improperly used or badly maintained.
  4. REMODECE is seeking to compile a database and computer programme of the various characteristics of residential electricity consumption in the EU countries
  5. The new EU Member States are much less advanced in terms of energy performance. The CEECAP project is seeking to identify the best way of introducing energy labels for devices in Eastern and Central Europe.


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