Owing to the proliferation of people in cities worldwide, the size of urban green areas has decreased along with biodiversity. Suwon City, a highly populated area adjacent to Seoul, the capital of the Republic of Korea, and the subject of this study, has been making significant efforts to prevent such a decrease in biodiversity. In this study, we aim to develop a suitable scenario for roof greening in Suwon City, analyze how the efficiency of increasing the suitable habitat area of the Paridae bird changes with the scenario, and propose the most efficient roof greening plan. For the development and application of this plan, public, commercial, and residential buildings were selected as target spaces to which roof greening was applied. Then, the appropriate roof greening area was determined (400000 m2, which is 0.712% of the area of Suwon) with reference to the Roof Greening Promotion Plan of Seoul. Subsequently, roof greening types were classified into low, medium, and high management based on the cases of roof greening. We found that the increase in the habitat area of Paridae depended on the types of roof greening and construction building. The buildings with the highest efficiency of increasing the habitat area in Suwon City (an increase of 1197.5%) were all commercial buildings except for those with low management, while the buildings with the lowest efficiency (115%) were public buildings. The information on the increases in the habitat area of Paridae and the cost of roof greening per area (m2) for the three types of building can be used to establish suitable green roofs that will promote urban biodiversity.