Tidsförlängning och underrättelseskyldighet vid hinder – En jämförande analys av AB 04 och NS 8405

Sammanfattning: The Swedish and Norwegian construction contract law is mainly regulated by standard-form contracts. In NJA 2018 p. 643 the Swedish Supreme Court takes guidance from the Norwegian standard-form contract NS 8405 and Norwegian construction contract law literature to decide the extent of a regulation in AB 04. Therefore, it is relevant to examine whether other regulations in the standard-form contracts correspond to each other in a way that makes it possible to use regulations in NS 8405 to decide the extent of corresponding regulations in AB 04. The purpose of the thesis is to compare the regulations of the contractor’s right to time extension, and the obligation to notify in case of impediments in AB 04 and NS 8405. The regulations are of importance to the standard-form contracts’ time frame. The thesis is delimited to a comparison of the regulations of time extension when the contractor has suffered an impediment due to the client. The thesis finds that the standard-form contracts’ area of application and purpose differ from each other. NS 8405 is delimited to application of major construction contracts, while AB 04 does not share this restriction. The regulations in the standard-form contracts regarding time extension affect the contracts in a corresponding way. The general duty of loyalty has a clearer effect on the regulation of time extension in case of impediment in AB 04 than the corresponding regulation in NS 8405. In both standard-form contracts the burden of proof regarding time extension is placed on the contractor. However, the evidentiary requirement is stricter in AB 04 than in NS 8405. The thesis also discusses the opportunity for a contractor to demand time extension due to a congregated number of impediments. The question has been tried in the Norwegian Supreme Court. The court found that this was possible. Therefore, there is a possibility that the Swedish Supreme Court would reach a similar conclusion. Additionally, the thesis states that there are obvious similarities regarding the client’s area of control and responsibilities within this. The analysis finds clear similarities regarding how time extension in case of an impediment which depends on the client is assessed. However, smaller differences exist. Consequently, deciding the extent of the regulation in AB 04 with guidance from NS 8405 should be performed with caution. Regarding the obligation to notify, the thesis finds that it would not be suitable to decide the extent of the regulation in AB 04 with guidance from NS 8405, since this obligation to notify is not given the same importance in AB 04 as in NS 8405. Additionally, the obligation to notify is more systematically structured in NS 8405 than in AB 04.