Research on the Design of Green Roofs for Office Buildings in Xuzhou Based on Building Energy Consumption Evaluation

The daily average air conditioning cooling load per unit building area of the top-floor rooms with a green roof was 1.05 kWh/m², which was 0.21 kWh/m² lower, achieving an energy-saving rate of 16.7%. Simulations using EnergyPlus for factors such as soil layer thickness, soil thermal conductivity, and leaf area index concluded that the soil thickness should not exceed 0.3 meters, the lower the soil thermal conductivity the better, and the larger the leaf area index the better.

Finally, taking Building No. 2 in the Materials Market as an example for renovation, it was found that the energy-saving rate of the renovated green roof was 27.0%. Modular design steps for green roofs were provided, with a suggested cost of around 204 RMB/m², effectively applying the research to practice.