When buying land in a residential area in Japan, many envision maximizing the space with a large, box-shaped house. However, the reality often involves a strict rule known as the "North-side Sloping Line Restriction. (北側斜線制限)" Simply put, to ensure sunlight for neighbors to your north, the law mandates a height limit for the northern side of your building. Depending on the plan, this might make a 3-story house impossible, or significantly reduce living space on the 2nd floor,