We assessed the energy demand of a typical detached house in Finland in the observed recent and anticipated future climatic conditions. Hourly test reference weather data sets spanning a whole year (2030, 2050 and 2100) were used as input to a dynamic building energy simulation tool. The annual energy demand for heating of spaces and ventilation supply air thus simulated was found to decrease by 20-40% by 2100, while the energy demand for cooling was found to increase by 40-80%, the ranges illustrating the uncertainty arising from the future evolution of greenhouse gas emissions. The impacts of the changing climate on delivered energy consumption and energy costs at a household level were examined using three different combinations of heating and cooling techniques. Despite the increases in energy use in May to August, the annual sum of delivered energy consumed in heating and cooling was estimated to decrease by 20-35% by 2100, depending on the magnitude of the climate change. Based on a long-term economic analysis, and also taking into account the energy used in buildings for other purposes, the net present value of households' energy costs in 2100 would be 5-10% lower than without climate change. (C) 2015 Elsevier B.V. All rights reserved.