This Guide sets out the rules for the drafting and presentation of candidate harmonized European Standards (hENs) for construction products drafted in the framework of Regulation (EU) 305/2011 (Construction Products Regulation). This Guide gives rules which are additional to the CEN-CENELEC Internal Regulations - Part 3 (based on ISO/IEC Directives, Part 2) when this is necessary because of the special provisions of harmonized product standards in the construction sector. This Guide applies to all new candidate hENs and for new Work Items (WIs) revising/amending existent hENs.