Stochastic assessment of the energy performance of buildings

A building’s energy performance is a complex multi-dimensional metric consisting of a variety of parameters. Presented herein are the results of a stochastic analysis of the factors affecting a building’s energy performance. The analysis is based on the Dwelling Energy Assessment Procedure (DEAP) (amended for cooling loads) and the general guidelines prescribed by the European Energy Performance of Buildings (EPBD) Directive 2010/31/EU. Modifications to the DEAP model are made for investigating the effect of variable external weather conditions on a building’s energy performance, and to incorporate the additional energy requirement for cooling. Subsequently, a stochastic analysis for three dwelling types is performed to assess the impact of 68 factors on the energy performance of buildings, for 12 different regions in Europe. It is concluded that (1) the factors with the greatest impact on energy use are in descending order, the floor area, external weather conditions, dwelling’s envelope u value (roof, window, walls, and floors), the space heating system, ventilation, windows area and walls area; (2) the energy performance of a building follows a lognormal probability distribution function; (3) buildings in colder EU regions exhibit higher energy profiles and higher variability in their energy profiles than those in warmer regions.