In 2006 an international standard, ISO 14025, was published on the principles and procedures of environmental product declarations (EPD). The standard gives requirements to the development of EPDs and PCRs and is used as a basis of EPD development within many EPD programmes globally. Despite an international standard, published EPDs today have different contents and format depending on who published the EPD. The main goal of EPDs is to provide objective, comparable and credible information about the environmental impacts of a product throughout its life cycle. These objectives can be diminished by the variations seen in EPDs and PCRs today. Through the mapping of six different international EPD programmes and the analysis of published PCRs and EPDs, this thesis shows that there is a need for communication between and harmonisation of EPD programmes at a global level. The main objective of this thesis is to contribute in the harmonisation of standards and guidelines for communication of environmental performance products and services in Norway. The thesis results in a recommendation to the Norwegian EPD Foundation within five areas; o format and layout of EPD o front page of EPD o environmental impact categories o user guide o online database