The architectural, engineering and construction industry (AEC Industry) needs to focus on the early design phases. The use of Lean Design Management and Building Information Model (BIM) can be used together for reducing uncertainty and improve communication. BIM requires new working methods, and the use of Level of Development (LoD) or model maturity is proposed as a key element to align the challenges in the design phase and to generate an enhanced design process. This paper addresses these challenges and aim to answer three research questions. RQ1: What approaches to model maturity are used or attempted in the Norwegian AEC industry? RQ2: What experiences do the actors of the AEC industry have towards the use of model maturity? RQ3: How can model maturity be implemented in an AEC project? The research method is based on a literature study and a study based on semi–structured interviews. This paper presents an analysis of the interviewees regarding the experiences the industry has with the use of model maturity. There is proposed a framework based on the results, about how to implement model maturity in construction projects. The framework is generic and can be adapted to different construction projects independent of contract form.