The calculation method is based on the appropriate design thermal conductivities or design thermal resistances of the materials and products for the application concerned.

The method applies to components and elements consisting of thermally homogeneous layers (which can include air layers).

ISO 6946:2017 also provides an approximate method that can be used for elements containing inhomogeneous layers, including the effect of metal fasteners, by means of a correction term given in Annex F. Other cases where insulation is bridged by metal are outside the scope of ISO 6946:2017.

NOTE Table 1 in the Introduction shows the relative position of ISO 6946:2017 within the set of EPB standards in the context of the modular structure as set out in ISO 52000-1.

This document also applies to the common spaces in multi-unit residential buildings. Recommendations regarding residential units are given in Annex A.

This document also contains provisions with respect to outdoor features directly concerned with access to a building or a group of buildings from a relevant site boundary, or between such a group of buildings within a common site. This document does not deal with elements of the external environment, such as public open spaces, whose function is self-contained and unrelated to the use of a specific building.

This document is applicable to new buildings and new work in existing buildings.

This document introduces the concept of ‘exceptional considerations for existing buildings’ for situations where it is exceptionally difficult to meet the requirements specified and, thus, impossible to provide full accessibility. By means of ‘exceptional considerations for existing buildings’, an acceptable, though restricted, level of accessibility is specified. An exceptional consideration for existing buildings is not to be applied in other situations or invoked in an unjustified manner, or as an excuse for not achieving a higher level of accessibility, where this is economically and/or technically feasible.

The dimensions stated in this document, relevant to the use of wheelchairs, are related to the footprint of commonly used wheelchair sizes and users as specified in ISO 7176-5 and ISO/TR 13570-2, 800 mm wide and 1 300 mm long.

This document is primarily written for adults with disabilities, but it includes some recommendations on specific accessibility needs of children.

ISO 21542:2011 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. It 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.