**2. Methods**

According to the Guideline for Chinese Environmental and Economic Accounting [5] and the characteristics of construction engineering, the environmental costs of buildings are divided into three parts: (1) green construction measures cost, which refers to the practical costs of protecting the environment during construction stage; (2) virtual abatement costs, which are used to control the emissions of pollutants in the life cycle of buildings, including water pollutants, air pollutants and solid waste pollutants, and where *Cva*1, *Cva*<sup>2</sup> and *Cva*<sup>3</sup> are the virtual abatement costs of air pollution, water pollution and solid waste pollution, respectively; (3) environmental degradation cost, which is the environmental loss cost caused by the emission and pollution of buildings, where *Ced*1, *Ced*<sup>2</sup> and *Ced*<sup>3</sup> are the environmental degradation costs of air pollution, water pollution and solid waste pollution, respectively.

The flowchart of the model is demonstrated in Figure 1. Based on the collected project inventory, three types of environmental pollution including air, water and solid waste pollution will be quantified. Based on the quantified results and the methods proposed in this paper, the virtual abatement costs and environmental degradation costs of the three types of environmental pollution can be obtained. Finally, the total environmental costs of a building will be obtained by adding green construction measures costs of subengineering fees including construction, decoration and erection works.

**Figure 1.** The flowchart of the model.
