An earth-sheltered structure built in the arid Negev Highlands of southern Israel was monitored during several seasonal periods in order to analyse its thermal behaviour and to determine the appropriateness of this type of building for the Negev and climatically similar regions. Temperatures were measured at various points within the building, which consists of two connected concrete shell domes totalling 58m2in floor area. A comparison of thermal conditions was made between various operating patterns, which included the introduction of shading and night ventilation for cooling and direct solar gain for heating. Mechanical heating was used in winter for the evaluation of energy input required to maintain comfort conditions. The paper analyses various thermal effects of the earth cover and of the particular envelope design, based on temperature measurements taken both in the interior space and within the soil, and evaluates the particular design approach taken in terms of its appropriateness for the given climatic conditions.