Objective At present, plants in residential areas in China are shading buildings, causing the problem of insufficient sunlight in buildings. Exploring the influence of plants on building sunlight through software numerical simulation analysis can provide a scientific basis for the construction of plant landscapes in residential areas, and can also provide a reference for further discussion on the implementation of ways to improve the living environment.

Method Taking the slab multi-storey residential buildings in Beijing as an example, an ideal building model was established. The basic unit of canopy spatial distribution was constructed according to the plant survey data obtained in the previous study. The impact on building sunshine was explored by Ecotect analysis software.

Result (1) The plant canopy within the 40° included angle between the building and the side of the building will have an impact on the building sunshine. The impact of plants in the green space between the buildings on the building sunshine was significantly higher than that of the green space beside the building. Both of them showed that the high-rise location was significantly higher than the low-rise location in the vertical direction, and the impact law in the horizontal direction was more complex. (2) The sensitivity classification of sunlight impact was carried out for the space next to the building. The sensitivity level Ⅰ (sensitive), level Ⅱ (generally sensitive) and level Ⅲ (insensitive) areas accounted for 10.2%, 56.2% and 33.6% of the total space volume, respectively. (3) The sensitive level Ⅰ area was not suitable for the existence of plant canopy, which directly affected the building’s sunshine compliance. The canopy distribution of level Ⅱ areas affected the total sunshine hours of building facades, and there was a possibility of affecting the sunshine hours of the second floor and above. The canopy distribution of level Ⅲ areas will not affect building sunshine.

Conclusion (1) Compared with the green space next to the building, the plant canopy of the green space between the buildings has a wider impact on the building sunshine, and the impact effect is also significantly higher. (2) There is a complex spatial relationship in the influence of plant canopies on building sunshine, and the degree and scope of the influence of plant canopies on building sunlight in different positions show great differences. (3) Different sunshine-sensitive zones have varied requirements for planting. The plant canopy in this area (level Ⅰ, level Ⅱ) will affect the sunshine hours of the building, and the design and management of plant landscape should be carefully carried out.