Here we write about NS 8415, NS 8416 and NS 8417 which are all drawn up to regulate the relationship between the main or general contractor and the sub- or total subcontractor, respectively. In the relationship between main and subcontractor (execution contracts), NS 8415 or NS 8416 is used, while NS 8417 is used in total subcontracting contracts. We have written about construction reforms, etc., in a separate article. There is a lot that is common in the three contacts. In our articles, which are mainly thematically designed, we have tried to show where in the individual contracts one finds the provisions relevant to the topic. However, our starting point is NS 8417 because it is this standard contract that we experience is most frequently used. We cannot reproduce the contract provisions in full, and we have only a few short quotations. When reading the articles, one should therefore have the collection “Legal Standards for Building and Construction” published by Norsk Standard at hand. It can be purchased in paper format and digitally at Norsk Standard.