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the building stock as the practices applied to the first buildings were then applied to the others. Over time, therefore, the energy performance of the whole group of buildings improved.

These encouraging results were also recorded in the SISPs that participated in the programme (fig. 4).

Voluntary Schools PLAGE projects

The Schools PLAGE project started up in 2009 and also produced impressive results. This PLAGE project was organised by a variety of networks. The results show reductions in fuel consumption as high as 22%, but electricity consumption in certain instances continued to increase. The reasons for this are relatively simple: we see an annual trend of a 2 - 3% increase over the whole of the tertiary buildings sector, mainly due to the increase in the amount of machinery used. PLAGE projects focus primarily on reducing fuel consumption, and address electricity consumption to a far lesser degree. Working on a boiler installation or optimising centralised hot water production are campaigns that can be carried out within a short space of time, while electricity consumption is much more widely dispersed throughout the building stock. Moreover, reducing electricity consumption requires changes in change consumer habits (e.g. photocopier usage, computer usage, etc.) which means that the effort required is much more disparate. In addition, in terms of cost, fuel consumption is much more onerous than electricity consumption.

This article concludes by presenting two local schools where interventions took place. The first is the municipal primary school, (preschool and primary school) in Forest (fig. 5). The establishment currently has 400 pupils with a heated surface area of almost 5,000 m². It was built in the 1930s and the energy efficiency is very low compared to the number of pupils. The pre-PLAGE energy cost per pupil/year was 206 euros. At the end of the programme, it was 142 euros per pupil/ year. Consumption dropped from 300 kWh/mVyear to 182 kWh/m²/year thanks to classic PLAGE actions: adapting the heating schedule to fit in with occupancy of the buildings. We tried to answer the following questions: Can heating start up later? How low can we set the heating? Can we lower the heating curves? Modify the boilers? Some boilers ran at one speed when they could run at two.

Fig . 3

It is interesting to note that situations within the municipalities were very different at the start in 2008. We note that it is easier to make far-reaching improvements with regard to energy to a group of buildings in very poor condition than to a group of buildings that is already quite efficient (© BE).

96 | Presentation and results of the “plage” projects