:envihab is a medical research facility of the Institute of Aerospace Medicine of the German Aerospace Center (DLR) where the effects of diverse environmental conditions on humans are being analyzed and explored as well as possible countermeasures are being developed. The name :envihab is a combination of the words “environment” and “habitat” (Latin: home/living space). The concept of :envihab is to deal with complex problems of a life support system and the interaction between humans and the environment from a medical, biological and psychological point of view. Major focus will be put on research topics that deal with providing for health and performance of humans. The modular house-in-house concept makes it possible to use the different units and the technical equipment without leaving the building. 12 test persons can permanently be exposed to equal and controlled environmental conditions. Total floor space of :envihab is approx. 3.500 square meters.