Abstract
This research discusses two different types of extreme weather data for building simulation, the Extreme Reference Years ERYs and the eXtreme Meteorological Years XMYs, with the aim of performing a comparison analysing their impact on the assessment of building energy performance. A dataset of 12 climates is used to generate both typical and extreme weather data, whose properties are examined both in terms of selected reference months and calculated heating and cooling degree-days. Finally, EnergyPlus simulations are run to evaluate the effects of the two alternative types of extreme weather data on the simulation outcomes.