This International Standard deals with the definition and calculation of surface area and volume indicators. In defining area measurement, this International Standard uses three measurement concepts: t he intra-muros and extra-muros concept used in many parts of the world; t he wall centre method of measurement used in many parts of the world; v ariations on these methods to comply with certain national laws, or for particular types of buildings. The surface area and volume indicators defined in this International Standard are intended for practical use, as a basis for measuring various aspects of the performance of buildings or as a planning aid. In other words, they should enable judgement to be made on functional, technical and economic aspects of buildings. This International Standard is intended to be used when establishing: specifications for the geometric performance of a building and its spaces (e.g. in design, purchasing procedures, etc., or in building regulations where appropriate); technical documentation relating to the performance of whole buildings prepared by designers, contractors and manufacturers; the amount of floor area that will not be effectively available for the placement of an individual’s workplace, furniture, equipment, or for circulation; evaluation, comparison or control of the properties of a building which are connected to its geometric performance. Although, as stated above, there are a variety of methods of area measurement around the world depending on the country and/or types of buildings, all measuring methods are not necessarily of practical use because of inability to identify real area (e.g. the wall centre method of measurement). Thus this International Standard specializes in the measurement solely for practical use.