Decreasing prices of photovoltaics (PV) and Lithium-ion batteries are creating a significant momentum for off-grid Zero Energy Buildings (ZEBs). In literature, most researchers have focused on grid-connected ZEBs built on site. This literature review is written with factory-made off-grid ZEBs in mind. High investment costs, poor construction quality and problems to achieve ZEB in real operation are three challenges that ZEB buildings currently face. This article discusses how automated mass production of continually improved standardized modules can overcome those problems. A shipping container is chosen as the modular unit to take advantage of the existing transport infrastructure. Due to the narrow width, the potential for utilizing daylight is better than that of traditional buildings. Off-grid ZEBs mean that the user must achieve ZEB in real operation, including plug loads. The local energy generation is likely to motivate the users to learn more about renewable energy. Plug loads is the largest energy consumer in buildings but are still often overlooked in ZEB definitions. With the Belt and Road initiative and political incentives to increase industrialized construction in China, the premises for exporting container buildings to the main markets in Asia and Africa are improving.