Using a finite-difference procedure, the dynamic energy response of indoor spaces under the influence of indoor energy pulses is analyzed. The method of analysis is simple and explicit and is based on the indoor surface thermal capacitance and heat-loss coefficient C(s) and L(s) respectively. It is demonstrated that these parameters characterize fully any specified indoor space, as far as its energy behaviour is concerned. Their values are calculated for an extended variety of indoor spaces, i.e. for various floor areas, floor dimensions ratios, indoor surface materials of envelope, partitions and furnishings, fenestration and indoor partitions areas. The range of validity of the present method of analysis is also defined and the corresponding deviations are quantified with reference to rigorous finite-difference solutions. The provided values of indoor space characteristics C(s) and L(s) may be used in a wide range of technological building applications, including comparisons and classifications of indoor spaces, design and selection of construction materials and furnishing as well as the investigation of effects from electric equipment, windows or doors opening, short-time ventilations, brief stay of visitors, etc. (C) 2010 Elsevier Ltd. All rights reserved.