The site is a lot in the northwest corner, adjacent to vacant lots to the south and southeast. This makes it impossible to predict the amount of daylight it would receive in the future. For this reason, we designed with the aim of allowing ample natural light into the house in any circumstance. The client requested spaces for hobby, especially a roof deck for astronomical observation and a loft for outdoor goods and play. We looked for a simple solution to meet all those conditions.First, we placed a main simple volume in the shape of a gable roof. After that, by adding and pulling small volumes from the main volume, we created inner/outer spaces for hobby and pleasure. This connects the family spaces and private spaces, allowing natural light to travel across the rooms while transmitting atmosphere.The rooms are allocated to invite natural light from the top side window of the loft all the way to the glass floor of the living room on the ground level. Light is reflected by the ceiling mirror, crosses through the glass floor of the MBR and reaches the living space. The dining room and a bedroom are connected by the volume under the outer stairs to the roof deck so that the rooms can share natural light.The terrace and the eaves are designed to block sunlight and heat in the summer. The house is well insulated in the winter and is equipped with a built-in air circulation system powered by solar panel.