The energy demand increases worldwide and due to the fact that fossil fuel is still dominating the energy mix, the corresponding CO2 emission becomes a more serious problem that threatens the global environment. The building sector is the largest energy consumer and it is of vital significance to reduce the primary energy consumption thus the CO2 emission in this sector. Under this constraint, the standards were set up to design buildings with relatively low energy consumption. Following the standard, the proposal phase of the buildings can be well regulated. However, it is equally important to check the energy consumption of the building in operating condition. In this project, a specific building was selected and its energy consumption condition was simulated both at building and neighbourhood level respectively. EnergyPlus was chosen to run the simulation at single building level and the results were compared with Minergie standard and the monitored data for the building. Another software, CitySim working at a larger scale, is also used. In order to validate the accuracy of the simulations, a benchmark was done based on the calculations of the idea load of the building in EnergyPlus and CitySim. The sources of errors were analysed in detail. At last, renewable resources were also integrated into the building to explore its plotentialof being a net-zero energy building.