A study on parametric design tool for residential buildings securing valid sunlight hours on the winter solstice

This study developed a design tool intended to suggest mass forms that can satisfy the standard of two consecutive sunlight hours on the winter solstice and achieve the maximum floor area ratio by identifying the relations between the relevant mass and surrounding buildings within and outside of the urban block, based on the plan created by an architect in line with design concepts at the initial stages. As a basic method to obtain two hours of consecutive sunlight, vector lines were drawn to connect the solar position and the two vertices at the bottom of the elevation. The plane created by the solar vector and the three-dimensional form created by the said plane were used to exclude the mass of adjacent buildings, subsequently preventing the entry of the buildings into the said three-dimensional shape in order to secure sunlight hours. In a bid to verify the design algorithms developed in this study, a variety of simulations were conducted, encompassing from buildings within a single block to nine multiple blocks on the three azimuth angles. The outcomes generated were able to meet the standard of two hours of consecutive sunlight, ensure sunlight hours for the adjacent buildings, and enable high-density development.