Blue-green roofs are vegetated roofs used for stormwater management purposes. With the roof serving several different purposes at the same time, the risk that any of its functions could be compromised needs to be addressed. Risks related to roof defects may present a threat to the long-term operation of a building, and could lead to waste by making defective products. This article presents an investigation to explore how the Norwegian building sector handles and manages this risk. Tender documents for green roof construction projects in the Norway are examined. Technical documents are studied to chart how the projects manage risks related to the integrity of the roofs in the tender phase. Findings suggest that risk in relation to building physics is not systematically analysed and managed in design and procurement phase of the project. Contractors are given significant control of design elements in certain common contract strategies. Risk is effectively not being managed in the early phase, with much of the risk management given to the contractors. The project owner will yield little control over decisions whose outcomes will only manifest long after the warranty period expires.