'A' House is located in a typical urban area named 'Yong-In' in Korea where recently developing rapidly. The site surrounded by low mountains that facing to the South and sitting on a sloping plot which is adjacent to neighbors. In this village, 'Tree-full Hills', each house unit has two level of boundaries: public boundary at the street level and individual boundary at the living level. The 'A' House celebrates interaction between families and neighbors while maintaining a strong sense of privacy and of ownership. Therefore the 'A' House is a place where degree of privacy is maintained with openings and spaces are merged in continuous spaces redefined by 'A-shaped' natural light which starts from one light at the top then spread out as it goes through two bottom openings under the 'A-shaped' roof also. The adjacency of the houses surrounding boundary and facing south lead to development of opening and massing that communicates maximum size and location of openings in the consideration of the light exposure and privacy from the public. The simple volume and a gable roof came from the strict application of local urban regulations and result reflected the client request: 1. Complying with prevailing site regulations; project should have sloping roof at least 70% of the floor area. Therefore, client want to have a typical 'gable' roof shape rather than having a portion of angled roof. 2. Client desire that all rooms able to meet the maximized light exposure orient to South. 3. While project has three separate floors, client asked to keep the connectivity between family members in terms of visual, sound and light. The main space in 'A' House is an triple height openings which connecting the diverse spaces by light and sensual connection. When light comes in, some spaces gets directly and other spaces get light through filtering which is light that comes into one space spread into another space. Also, other architectural components such as walls, doors, stairs and window frames are customized on site and designed to be harmonized with color white. Simple south facing volume layout not only maximizes surface area touching the given natural environment, but also reflects and communicates with surrounding urban settings and site regulations while having different architectural languages and maintaining a degree of privacy from the public.