Lojalitetsplikten i entreprenadavtal enligt ABT 06 - En analys av entreprenörens upplysningsplikt, samverkansskyldighet och Högsta domstolens praxis
(2025) LAGF03 20252Department of Law
Faculty of Law
- Abstract
- The thesis examines the meaning and scope of the duty of loyalty in construction contracts governed by ABT 06. The analysis focuses on the contractor’s duty to provide information, the parties’ obligation to cooperate, and how these duties have been shaped through case law from the Swedish Supreme Court.
The thesis shows that the duty of loyalty is neither expressly regulated in statutory law nor formulated as an independent provision in ABT 06, Instead, it appears as an underlying principle throughout the standard contract. The structure of ABT 06 presupposes openness, cooperation and mutual trust between the parties, which is also clearly expressed in the preamble and the accompanying commentaries. In practice, the duty of loyalty... (More) - The thesis examines the meaning and scope of the duty of loyalty in construction contracts governed by ABT 06. The analysis focuses on the contractor’s duty to provide information, the parties’ obligation to cooperate, and how these duties have been shaped through case law from the Swedish Supreme Court.
The thesis shows that the duty of loyalty is neither expressly regulated in statutory law nor formulated as an independent provision in ABT 06, Instead, it appears as an underlying principle throughout the standard contract. The structure of ABT 06 presupposes openness, cooperation and mutual trust between the parties, which is also clearly expressed in the preamble and the accompanying commentaries. In practice, the duty of loyalty mainly takes form through rules that require the parties to inform each other and to act cooperatively during the execution of the project.
A central aspect of the duty of loyalty in total contract is the contractor’s duty to inform. Since the contractor is responsible for both design and execution, the contractor usually has an informational advantage in relation to the client. This limits the client’s insight into technical and practical aspects of the project and makes the duty to provide relevant information particularly important. Through continuous information and communication, the client is given a real opportunity to take informed decisions, which contributes to a more balanced contractual relationship.
The duty to cooperate constitutes another key element of the duty of loyalty under ABT 06. Both parties are expected to act actively and contribute to the fulfilment of the contract, rather than focusing solely on their own interests. Cooperation and ongoing dialogue reduce the risk of misunderstandings and conflicts and are therefore essential for the practical functioning of long-term construction contracts.
The thesis also demonstrates that the duty of loyalty has been further clarified through the case law of the Swedish Supreme Court. In NJA 2017 p.203 and NJA p.1195, the Court emphasized that the duty of loyalty may require both active conduct and the provision of information, but that the duty is mutual. The cases show that passivity can lead to legal consequences, even where the other party had acted improperly. At the same time, the Court has made clear that the duty of loyalty is not unlimited and must be assessed considering the circumstances of the individual case.
Overall, the thesis concludes that the current role of the duty of loyalty in ABT 06 is largely functional. When applied as a supplementary principle to the contract, it supports cooperation and reduces the risk of disputes. However, the open and unwritten nature of the duty also entails a degree of legal uncertainty, as parties often only gain clarity on its scope after a dispute has arisen. Despite this, the continues development of the duty of loyalty through case law appears both necessary and appropriate, if it is applied with balance and respect for the agreed allocation of risks. (Less) - Abstract (Swedish)
- Uppsatsen syftar till att undersöka lojalitetspliktens innebörd och omfattning i entreprenadavtal, enligt ABT 06. Fokus i uppsatsen ligger på hur lojalitetsplikten kommer till uttryck i standardavtalet, särskilt genom entreprenörens upplysningsplikt och parternas samverkansskyldighet. Uppsatsen tittar även på hur lojalitetsplikten har utvecklats genom Högsta domstolens praxis. Syftet har varit att klargöra vad lojalitetsplikten faktiskt innebär i ett entreprenadförhållande. Fortsatt har syftet även varit att bedöma ifall principen leder till en rimlig ansvarsfördelning mellan beställare och entreprenör.
Uppsatsen framkommer att lojalitetsplikten varken är lagreglerad eller skriven som en egen bestämmelse i ABT 06. I stället märks den... (More) - Uppsatsen syftar till att undersöka lojalitetspliktens innebörd och omfattning i entreprenadavtal, enligt ABT 06. Fokus i uppsatsen ligger på hur lojalitetsplikten kommer till uttryck i standardavtalet, särskilt genom entreprenörens upplysningsplikt och parternas samverkansskyldighet. Uppsatsen tittar även på hur lojalitetsplikten har utvecklats genom Högsta domstolens praxis. Syftet har varit att klargöra vad lojalitetsplikten faktiskt innebär i ett entreprenadförhållande. Fortsatt har syftet även varit att bedöma ifall principen leder till en rimlig ansvarsfördelning mellan beställare och entreprenör.
Uppsatsen framkommer att lojalitetsplikten varken är lagreglerad eller skriven som en egen bestämmelse i ABT 06. I stället märks den genom hela avtalet. I förordet betonas bland annat öppenhet, förtroende och en rimlig balans mellan parternas rättigheter och skyldigheter. I praktiken tar lojalitetsplikten form genom regler som bygger på att parterna informerar varandra och samarbetar under entreprenadens gång. Det blir extra viktigt i totalentreprenader, eftersom entreprenören ansvarar för både projektering och utförande och därför ofta har mer information än beställaren. Upplysningsplikten och samverkankraven hjälper då till att jämna ut den obalansen, så att beställaren kan ta del av bättre underlag.
I den praxis som analyseras i uppsatsen tydliggör Högsta domstolen att lojalitetsplikten i långvariga avtalsförhållanden kan innebära krav på både upplysning och aktivt agerande. Högsta domstolen lyfter också fram att lojalitetsplikten är ömsesidig; även den part som anser sig ha blivit illa behandlad kan inte vara passiv hur länge som helst utan att förlora sina egna rättigheter. Praxis markerar att lojalitetsplikten både kan ge skydd och samtidigt ställa krav.
I analysen diskuteras om lojalitetsplikten är rimlig eller riskerar att bli betungande. Å ena sidan fungerar den som en nödvändig utfyllnad i entreprenader där det är svårt att i förväg reglera alla situationer. Å andra sidan skapar principens öppna karaktär en viss osäkerhet. Om lojalitetsplikten tillämpas för långtgående finns en risk att ansvar flyttas bortom den riskfördelning som parterna faktiskt avtalat om, vilket kan bli särskilt krävande för entreprenören.
Sammantaget talar uppsatsens resultat för att lojalitetsplikten i ABT 06, i huvudsak fyller en viktig funktion och kan bidra till en balanserad ansvarsfördelning. Detta fungerar dock bara om den används med viss återhållsamhet och knyts till avtalets struktur och omständigheterna i det enskilda fallet. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9217600
- author
- Marante Krumpacnik, Claudia LU
- supervisor
-
- Sandra Ahrén LU
- organization
- course
- LAGF03 20252
- year
- 2025
- type
- M2 - Bachelor Degree
- subject
- keywords
- Avtalsrätt, Sakrätt, Entreprenadrätt, Standardavtal, Lojalitetsplikt
- language
- Swedish
- id
- 9217600
- date added to LUP
- 2026-02-09 15:34:42
- date last changed
- 2026-02-09 15:34:42
@misc{9217600,
abstract = {{The thesis examines the meaning and scope of the duty of loyalty in construction contracts governed by ABT 06. The analysis focuses on the contractor’s duty to provide information, the parties’ obligation to cooperate, and how these duties have been shaped through case law from the Swedish Supreme Court.
The thesis shows that the duty of loyalty is neither expressly regulated in statutory law nor formulated as an independent provision in ABT 06, Instead, it appears as an underlying principle throughout the standard contract. The structure of ABT 06 presupposes openness, cooperation and mutual trust between the parties, which is also clearly expressed in the preamble and the accompanying commentaries. In practice, the duty of loyalty mainly takes form through rules that require the parties to inform each other and to act cooperatively during the execution of the project.
A central aspect of the duty of loyalty in total contract is the contractor’s duty to inform. Since the contractor is responsible for both design and execution, the contractor usually has an informational advantage in relation to the client. This limits the client’s insight into technical and practical aspects of the project and makes the duty to provide relevant information particularly important. Through continuous information and communication, the client is given a real opportunity to take informed decisions, which contributes to a more balanced contractual relationship.
The duty to cooperate constitutes another key element of the duty of loyalty under ABT 06. Both parties are expected to act actively and contribute to the fulfilment of the contract, rather than focusing solely on their own interests. Cooperation and ongoing dialogue reduce the risk of misunderstandings and conflicts and are therefore essential for the practical functioning of long-term construction contracts.
The thesis also demonstrates that the duty of loyalty has been further clarified through the case law of the Swedish Supreme Court. In NJA 2017 p.203 and NJA p.1195, the Court emphasized that the duty of loyalty may require both active conduct and the provision of information, but that the duty is mutual. The cases show that passivity can lead to legal consequences, even where the other party had acted improperly. At the same time, the Court has made clear that the duty of loyalty is not unlimited and must be assessed considering the circumstances of the individual case.
Overall, the thesis concludes that the current role of the duty of loyalty in ABT 06 is largely functional. When applied as a supplementary principle to the contract, it supports cooperation and reduces the risk of disputes. However, the open and unwritten nature of the duty also entails a degree of legal uncertainty, as parties often only gain clarity on its scope after a dispute has arisen. Despite this, the continues development of the duty of loyalty through case law appears both necessary and appropriate, if it is applied with balance and respect for the agreed allocation of risks.}},
author = {{Marante Krumpacnik, Claudia}},
language = {{swe}},
note = {{Student Paper}},
title = {{Lojalitetsplikten i entreprenadavtal enligt ABT 06 - En analys av entreprenörens upplysningsplikt, samverkansskyldighet och Högsta domstolens praxis}},
year = {{2025}},
}