A transportable modular container building for military and/or humanitarian field operations, in particular as a container-based field kitchen, comprising a first and a second walk-in container (12, 14) which can be positioned in at least one defined orientation relative to one another at a deployment site, comprising a power generating unit with an internal combustion engine, characterized in that the container building further comprises: a first heat exchanger which is thermally coupled to the combustion engine, wherein the power generating unit with the internal combustion engine and the first heat exchanger is arranged in the first container, a burner operated parking heater, a first pipeline circuit filled with liquid, to which the first heat exchanger and the parking heater are connected to heat the liquid, wherein the first pipeline circuit comprises a first pipeline subcircuit arranged in the first container and a second pipeline subcircuit arranged in the second container, and wherein the first pipeline subcircuit and the second pipeline subcircuit each have two coupling ports (52, 56, 64, 66) through which the first pipeline subcircuit and the second pipeline subcircuit are releasably connectable to form a first overall circuit, when the first and second containers (12, 14) are positioned at the deployment site, a first pump arranged in the first pipeline circuit and configured to circulate the fluid in the first pipeline circuit, with the first pump being electrically connected to the power generating unit, a fresh water tank (82a, 82b) for providing fresh water, a fresh water outlet mounted in the second container, a second pipeline circuit connecting the fresh water tank (82a, 82b) and the fresh water outlet, and a second heat exchanger arranged in the first pipeline circuit and the second pipeline circuit for heating fresh water from the fresh water tank (82a, 82b) using the liquid from the first pipeline circuit. a first heat exchanger which is thermally coupled to the combustion engine, wherein the power generating unit with the internal combustion engine and the first heat exchanger is arranged in the first container, a burner operated parking heater, a first pipeline circuit filled with liquid, to which the first heat exchanger and the parking heater are connected to heat the liquid, wherein the first pipeline circuit comprises a first pipeline subcircuit arranged in the first container and a second pipeline subcircuit arranged in the second container, and wherein the first pipeline subcircuit and the second pipeline subcircuit each have two coupling ports (52, 56, 64, 66) through which the first pipeline subcircuit and the second pipeline subcircuit are releasably connectable to form a first overall circuit, when the first and second containers (12, 14) are positioned at the deployment site, a first pump arranged in the first pipeline circuit and configured to circulate the fluid in the first pipeline circuit, with the first pump being electrically connected to the power generating unit, a fresh water tank (82a, 82b) for providing fresh water, a fresh water outlet mounted in the second container, a second pipeline circuit connecting the fresh water tank (82a, 82b) and the fresh water outlet, and a second heat exchanger arranged in the first pipeline circuit and the second pipeline circuit for heating fresh water from the fresh water tank (82a, 82b) using the liquid from the first pipeline circuit.