The development capacity in a lot is limited by legal density and sky exposure plane control. The physical control standards, such as F.A.R., building coverage, sky exposure plan control, are important factors to manage urban space. But this has resulted in many problems such as skyline control, heigh density developments, land-use problems and lack of city identity. So major cities in foreign countries are administering various unique height control methods that are adaptable to the city. Therefore, it is essential to know accurately the influences of the physical control standards in urban space. The purpose of this study is to analyze the controlling mechanism of the building envelope design methods in a residential area according to the condition change and to predict the density. AutoCAD program was used with the data which were obtained by the cadastral map, regulation, statistics. The sample size was 21area in Seoul residential area. The results of this study were as follows; Control effect of the restrictions was change according to the size of housing site and proportion, direction of the main load and width and the restrictions of architectural slant line for daylight and the diagonal plane control by Street width are excessively act on small lot in a residential area. Therethrough the Attainable F.A.R., the building envelope design and building arrangement are irrational in a small lot.