The performance of a passive heated and cooled education building, located in Israel's Negev desert, is studied. A year's worth of measured data are presented and analysed from the viewpoint of thermal comfort, Winter heating, which is effected via direct-gain passive solar means, is found to provide comfort conditions without the need for a backup system. Summer cooling is provided via the use of enhanced nocturnal ventilation, a method which is suitable for the particular desert location involved. The cooling system is found to be satisfactory, with certain qualifications. In addition to site-specific results, some conclusions of a more general nature are drawn regarding the design of passive solar public buildings.