[en] 50 years of progressively strengthened energy requirements in the Danish building code appear to be a success, as the energy consumption has remained constant despite an increase in the total area in requirement of heating. This article however argues that the building code mechanism is heavily influenced by path dependent regime structuration processes, and that the mechanism constitutes a barrier to more radical developments within low energy housing. Few and poorly organized frontrunner activities within low energy housing have accordingly taken place in a Danish context during the past decades. Finally it is proposed that the current development within the energy system provides opportunities for cultivating an improved transitional awareness and for carrying out experimental activities that may challenge the path dependencies of prevailing regime structuration processes. - Highlights: ► We analyze the role of the building code energy strategy as an incumbent regime. ► Regime independent development activities such as passive houses are retained. ► Industry is characterized by adaptive capacity to support radical development. ► Adaptive capacity needs to be mobilized and configure by regime problematizations. ► Governance capabilities to achieve such a mobilization are presently in short supply.