Recently, the concept of a Green Investment Scheme (GIS) has been developing rapidly and gained pace in 2008 when Hungary and Latvia adopted the GIS legislature and at least three more European countries prepared to follow suit. Against this background, the paper examines the Hungarian case looking into its legal framework, possible GIS architectures and the countrys actual choice regarding the modality of a Green Investmet Scheme. An overarching question is the allocation of revenues from sales of assigned amount units (AAUs). The primary focus of this paper is on the allocation of AAU revenues to the buildings sector since the latter represents one of the priority areas to be addressed in the context of climate change mitigation. On this basis, an overview of existing national and EU subsidy systems supporring energy efficiency in the Hungarian buildings sector is presented. The authors point to a complementary nature of Hungarian Green Investment Schemes which are supposed to address the projects weakly supported by other policies. In addition, the experiences of CEE countries in energy efficiency projects in buildings are reviewed to the extent which can be relevant for selecting appropriate GIS architecture modalities. Furthermore, the paper addresses the issue of similarity between JI (Track 1) and GIS projects and gives certain recommendations with regard to implementation of Green Investment Schemes in the buildings sector.