Buildings are responsible for 38% of energy-related carbon dioxide emissions, and the global building stock is expected to double by 2060. The building sector is a sleeping giant for climate mitigation and adaptation. The Programme for Energy Efficiency in Buildings (PEEB) aims to transform the building sector by promoting sustainable building design and construction. PEEB combines financing for energy efficiency in large-scale projects with technical assistance through policy advice. PEEB mobilizes innovative financing solutions for large building projects such as hospitals or schools, but also large national green building programmes. PEEB supports its partner countries to make policies, standards and NDCs more ambitious and effective to channel investments towards green buildings. Capacity-building for professionals and decision-makers in the building sector prepares the ground for investments. PEEB is catalysed by the Global Alliance for Buildings and Construction (GlobalABC) and supports the implementation of the GlobalABC roadmap “Towards low GHG and resilient buildings”. The programme was initiated by the governments of France and Germany at COP22 in 2016.