Check whether there is a national annex to harmonised product standards
There are more than 440 harmonised product standards. This means that the vast majority of usual construction products are covered by harmonised product standards.
Difference in local, geographical, climatic conditions, may justify the existence of national annexes. Be aware that Norway may prepare national supplements (labelled NA) for a number of harmonised product standards, such as:
NS-EN 206 Concrete - Part 1: Specification, performance, production and conformity.
NS-EN 13240: 2001 Roomheaters fired by solid fuel - Requirements and test methods.
NS-EN 12566-3 Small wastewater treatment systems for up to 50 PT - Part 3: Packaged and/or site assembled domestic wastewater treatment plants.