Harmonised standards in general
Harmonised standards (hENs) are crucial elements of the common approach to products across EU. Whereas legislation (directives, regulations etc.) set out the principles, harmonised standards deal with issues specific for the particular product family. hENs provide with common technical language, define requirements, essential characteristics and the methods of their assessment. In principle, they are used to demonstrate that products, services, or processes comply with relevant EU legislation. See the list of product groups where hENs are used. The degree of obligation is defined in the relevant legal act and may vary.
Harmonised standards for construction products
According to Construction Product Regulation 305/2011 (CPR), the use of hENs for construction products is mandatory. Every hEN for a construction product has an Annex ZA where the level of AVCP is given along with the list of essential characteristics which can be assessed and declared.
Unlike hENs for most of other areas, hENs for construction products should not contain requirements for products. This is an issue of great concern, surrounded by lots of misunderstanding and confusion.
Harmonised standards are first prepared by Technical Committees of CEN. They consist mainly of experts nominated by national standardisation bodies, possibly representatives of industrial associations and independent experts. Draft standards are consulted amongst national standardisation bodies in several stages.
The content of a hEN must be in line with a mandate or a standardisation request. These documents are published by European Commission upon consultations with EU member states. The European Commission may publish other documents shaping the content of the hEN. The Technical Committees of CEN are only supposed to elaborate technical details within the concept determined by the European Commission.
Once this process is finished, the standards are assessed by European Commission experts for their suitability to become harmonised standards. A pool of HAS Consultants is in charge to assist at this stage. Many standards fail at this stage which is the reason why new versions of some standards are not harmonised (the old version is still to be used for DoP and CE-marking).
New harmonised standards are cited in the Official Journal of the European Commission. The most convenient tool for finding the standard is the Nando database. It is necessary to read the actual text of the standards to be sure whether the product falls under the scope of the standard or not.
hENs are normally accessible through national standardisation bodies which are responsible for the translation. There have been a number of discussions on free availability of hENs as they are mandatory.