Even though industry consumes nearly half of total energy production, the relative share of total energy consumption related to heating and operating buildings is growing constantly. The motivation for this study was to reveal the differences in electricity use and district heating consumption in school buildings of various ages during the working day and also during the night when human-based consumption is low. The overall aim of this study is to compare the energy (electricity and heating) consumption of six school buildings in Kuopio, Eastern Finland. The selected school buildings were built in different decades, and their ventilation and building automation systems are also inconsistent. The hourly energy consumption data was received from Kuopion Energia, the local energy supply company. In this paper, the results of data analysis on the energy consumption in these school buildings are presented. Preliminary results show that, generally speaking, new school buildings are more energy-efficient than older ones. However, concerning energy efficiency, two very new schools were exceptional because ventilation was on day and night in order to dry the building materials in the constructions. The novelty of this study is that it makes use of hourly smart metering consumption data on electricity and district heating, using modern computational methods to analyse complex multivariate data in order to increase knowledge of the buildings' consumption profiles and energy efficiency. (C) 2015 Elsevier Ltd. All rights reserved.