This International Standard specifies a range of requirements and recommendations for many of the elements of construction, assemblies, components and fittings which comprise the built environment. These requirements relate to the constructional aspects of access to buildings, to circulation within buildings, to egress from buildings in the normal course of events and evacuation in the event of an emergency. An informative annex is also included which deals with aspects of accessibility management in buildings. This International Standard contains provisions with respect to features in the external environment directly concerned with access to a building or group of buildings from the edge of the relevant site boundary or between such groups of buildings within a common site. This International Standard does not deal with those elements of the external environment, such as public open spaces, whose function is self-contained and unrelated to the use of one specific building, nor does it deal with single family dwellings, other than those circulation spaces and fittings that are common to two or more such dwellings. At present, consideration is being given to the development and publication of additional parts to this International Standard to deal with the types of external environments described above and single family dwellings. For existing buildings there are options included in some paragraphs which appear as “exceptional considerations for existing buildings in developing countries” (see “Guidance on the Implications of the ISO Global Relevance Policy for CEN Standardization”, 2005) and as “exceptional considerations for existing buildings” where a lesser standard than expected in new developments is accepted on the grounds of technical and economic circumstances only. The dimensions stated in this International Standard, relevant to the use of wheelchairs, are related to the footprint of commonly used wheelchair sizes and users. The footprint for a wheelchair within this International Standard is based on ISO 7176-5 and ISO/TR 13570-2 and is 800 mm wide and 1 300 mm long. For larger wheelchairs and scooters, dimensions will have to be considered accordingly. NOTE This International Standard is primarily written for adults with disabilities but it includes some specifications regarding the specific accessibility requirements that would suit children with disabilities. However, it is envisaged that more detailed requirements will be included in future revisions of this International Standard.