The objective of this product category rules (PCR) project is two-fold: to develop an international common operational methodology for building products environmental declarations (ED), and to identify aspects that are not yet agreed upon. This PCR cover technical aspects relevant for the declaration of building products based on a life-cycle assessment (LCA) covering the 'cradle-to-gate' perspective. The PCR also include specifications to develop a PCR on building products' applications that account for a full life cycle (cradle-to-grave). Only when the LCA covers a full life cycle is it, in theory, possible to use the result for supporting decision-making in comparative purpose, provided that a common functional unit can be established. The development of EDs also makes the type III declaration a useful tool to aid consumers in decision-making. To comply with the ISO 14025 standard for EDs, this PCR has to be complemented by administrative rules that are relevant to a program operator and the environmental declaration type III program that is specified by this program body. For implementation on the Swedish market, the PCR developed here will be complemented with such administrative issues defined in the type III program 'Requirements for Environmental Product Declarations', hosted by the Swedish Environmental Management Council (MSR).