Insufficient energy monitoring was a main problem encountered in the field study. For example, the consumption of several buildings with different types of usage was measured using the same meter, which makes an accurate analysis very difficult. Often, there was a canteen or a gym integrated into a school building and the total consumption counted on a single meter. As already mentioned, a British study of school buildings determined that energy consumption in schools providing catering increased by 7-10%, whereas the energy consumption can increase up to 20% if the school premises include a gym [10]. Especially the electricity consumption varies more if the school has a large canteen kitchen (Fig. 7). To assess the impact of large kitchens and to estimate the electricity consumption of these kitchens in each building