Journal of Civil Engineering and Architecture 15 (2021) 103-117 doi: 10.17265/1934-7359/2021.02.006 Surpassing the Limits to Human Cognition? On the Level of Detail in the Norwegian Building Design Guides Erlend Andenæs 1 , Berit Time 2 , Tore Kvande 1 and Jardar Lohne 1 1. Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Høgskoleringen 7A, Trondheim 7491, Norway 2. SINTEF Community, Høgskoleringen 7B, Trondheim 7465, Norway Abstract: The SINTEF Building Research Design Guides are a series of Norwegian building technical recommendations. The design guides are highly reputed and widely used in the Norwegian construction sector, serving as a link between the technical regulations and the design process of the individual construction project. This paper examines the element of risk in the use of multiple design guides to extract information about a topic not explicitly covered by any single guide, using the example of blue-green roofs. The research has been conducted in the form of a document study. While the advice given in the design guides is both valid and coherent, the amount of information presented is likely to be overwhelming for industry professionals. There are great degrees of awareness of quality risk present in the individual design guides, but an overall risk picture is not presented. Input from the fields of project management and psychology can help develop risk awareness strategies. The design guides may benefit from an aggregate level of information, where main technical challenges are grouped into super-level categories. Key words: Risk, quality risk, blue-green roofs, human cognition. 1. Introduction In Norway, the requirements of the building code are given on a function-based level [1]. The technical regulations for buildings (TEK17 [2]) specify requirements of the Planning and Building Act of 2008. Any technical solution may be chosen as long as it complies with these requirements. The Norwegian Building Authority [3] expresses the structure of the legislation as follows: “The collected requirements of the government, defined in the Planning and Building Act and its associated regulations, set a minimum level of quality and safety to be fulfilled by the finished building. TEK10 [The Technical Regulations of 2010] specifies requirements on all essential topics pertaining to health, safety, environment, and usability. The requirements are stated in the form of overall, Corresponding author: Erlend Andenæs, Ph.D. candidate, M. Sc., research fields: Building materials, blue-green roofs, quality risk. qualitative, functional requirements” (our translation). Note that the functional structure and role of the current regulations (TEK17) are identical to that of TEK10 [4]. This form of legislation gives architects and designers wide freedom, but there is also an inherent risk in that this large degree of freedom left to designers entails a potential high level of quality risk—preliminarily defined here as the probability and consequences of technical building defects. The core of the issue is to ensure that the chosen solution will remain functional throughout its intended life span. Challenges of quality risk in the built environment today can be exemplified through the introduction of so-called blue-green roofs [5]. One challenge brought by climate change in the Nordic region is an increase of the number and intensity of precipitation events [6]. Heavy rainfall may exceed the capacity of urban stormwater drainage systems, necessitating local measurements to retain and detain stormwater. Blue-green roofs, wherein vegetated roof assemblies D DAVID PUBLISHING