eXtra-eXtra-Small House is located in a specific part of the centre of Ljubljana. The neighbourhood called Krakovo has the character of an historical village, which in the Middle Ages supplied the nearby monastery with fresh food and is today a highly protected historical area. The basic dimensions of the new house were already defined by law according to the volume of the pre-existing 100 year old housing. The task was to integrate all residential functions in an extra small volume to suit the needs of a couple living in their new urban holiday-home. Since the house faces north, it was a challenge to bring the direct and indirect sunlight to the living spaces in the ground floor. The heritage protection rules allow light shafts on the roofs, but in this case we also turned them 90 degrees. A huge wall size slide window opens up the space to the intimate atrium and allows for indirect lighting. The concept of raw materials stretches from exterior to interior - using fibre cement panels in their primer mode for the roof and yard facade and 'beton brutNULL, terrazzo, plywood, iron, felt for the indoor. The total area of 43 sq m ultimately names the house.