Based on the analysis of the characteristics of the three types of residential balcony construction area calculation rules since the founding of the People’s Republic of China, the rules that the construction area should be calculated separately according to whether the residential balcony is closed or not are proposed, and the impact mechanism of the rules on the economic benefits and land cost of residential development, as well as the different manifestations in different periods and regions, are clarified. The changes and problems caused by residential design were discussed from four aspects: residential balcony function, indoor physical environment, safety performance and external landscape, and countermeasures and suggestions were put forward to improve the residential balcony area calculation rules, deepen the floor area ratio management regulations, strengthen the review, management and enrichment of design theory of area calculation, so as to guide the scientific and reasonable design of residential balcony.