The document specifies the characetristics related to dynamic thermal behaviour of complete building components and gives methods for their calculation. It also defines the information on building materials, required for its use. The dynamic thermal characteristics (thermal admittance, periodic thermal conductances, thermal capacities) defined in this standard can be used in products specifications of complete building components. This second edition shall cancel and replace the first edition of 1999-09. Principal changes to the clauses that have been technically revised are: Clause 2: ISO 10077-2 and EN 13465 added Clause 3: All equations reviewed and corrected as necessary Clause 3.1.5: Definition of heat capacity changed Clause 7.2.1, 7.2.2: All equations reviewed and corrected as necessary Clause 7.2.3: Added equation for periodic thermal transmittance. Added footnote 1. Annex A: Equation (A.4) corrected Annex B: Minor revisions to B.2.1 and B.2.2 Annex C: Added Table C.1 Annex D: Amended examples to align with changes to the formulae in the main text