Abstract

Previously, only solutions with long-term experience were used in the building sector and it was sufficient to describe, e.g. in the building regulations, how they should be constructed. However, the innovation rate has gradually increased, encouraged by industrialization and by building regulations becoming more functional based. As a result, the required performance is often described for the whole building or for a building component, but not at product level. Furthermore, CE marking makes it possible to market and sell a product in any country within the European Union if only one or a few properties are declared, and these may even not be the most relevant ones for a specific application in a technical solution. A CE mark is therefore neither a quality mark nor an approval of the product for a specific application, although clients and consultants often believe this is the case. It is therefore a major challenge for the building sector to determine if a new building product is suitable in a specific technical solution (wall, roof, etc.). The paper identifies a gap between performance-based requirements for a technical solution and specific requirements to properties of building products. Two cases (flat roofs with no slope, MgO-containing boards used as wind barriers) show the possible economic consequences of not closing this gap; the technical solution failed, as one of the products was not suitable for Danish weather conditions. The first case initiated the formation of the Danish Building Defects Fund in 1986, the second one from 2015 shows that the gap still exits, 30 years later. The cases show how difficult it can be even for professionals to understand different certifications, especially when a product seems to be well suited for a specific use. Based on the cases, the paper presents a systematic approach that guides users through important issues relating to requirements for a moisture-safe building envelope.