In Korea, apartments account for over 50 percent of the housing types. Residential spaces soaring higher and growing denser accompany the violation of the right to have sunshine duration hours and invite disputes among adjacent buildings. According to the court's ruling, the sunshine duration measurement of a residential area is based on the winter solstice. Sunshine duration should be over two hours from 9 a.m. to 3 p.m., or at least four hours from 8 a.m. to 4 p.m. One of the ways to measure sunshine duration is to measure sunshine duration on the site in question. However, the court does not accept that because sunshine duration measurement is possible only once a year using that method. The court measures sunshine duration hours using a 3-dimensional computer simulation and makes an evaluation for court case data. Accordingly, this essay suggests how to simulate the sunshine duration of an apartment using Autodesk VIZ program and attempts to verify the validity of the simulation results in comparison with the result of the sunshine duration measurement of an apartment.